i

Materials Science and

Engineering Laboratory

FY 2004 Programs and

Accomplishments

Polymers

Division

Eric J. Amis, Chief

Chad R. Snyder, Deputy

NISTIR 7126

September 2004

National Institute of

Standards and Technology

Arden L. Bement, Jr.

Director

Technology

Administration

Phillip J. Bond

Undersecretary of

Commerce for Technology

U.S. Department

of Commerce

Donald L. Evans

Secretary
ii

Certain commercial entities, equipment, or materials may be identified in this document in order to

describe an experimental procedure or concept adequately. Such identification is not intended to imply

recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended

to imply that the entities, materials, or equipment are necessarily the best available for the purpose.
iii

Table of Contents

Table of Contents

Executive Summary ...................................................................................................................1

Technical Highlights:

Coherent Anti-Stokes Raman Scattering (CARS) for

In-Situ Chemical Imaging of Tissue Engineering Constructs.............................................2

Use of Reverse Transcriptase Polymerase Chain Reaction

(RT-PCR) to Measure Cellular Responses ........................................................................4

Profiling the Photoresist-Liquid Interface: Fundamentals

for Immersion Lithography and Polymer Dissolution .........................................................6

Dielectric Metrology and Test Methods Supporting

Embedded Passive Device Technology ..............................................................................8

High-Throughput Measurement of Interfacial Tension ....................................................10

Polymer Library Fabrication Techniques Using

Microfluidic Technology ....................................................................................................12

MALDI-MS Interlaboratory Comparison of Polymer Mixtures ......................................14

Extraordinary Transport Properties of Nanotube/Polymer Nanocomposites ................... 16

Advanced Manufacturing Processes ......................................................................................19

NIST Combinatorial Methods Center (NCMC)

Pioneer and Partner in Accelerated Materials Research ........................................... 20

Polymer Formulations: Rapid Prototyping Technology

for Polymeric Materials Development .............................................................................. 21

Carbon Nanotube Processing ........................................................................................... 22

Processing Flows and Instabilities.....................................................................................23

Quantitative Polymer Mass Spectrometry ........................................................................24

Polymer Standards ............................................................................................................25

Biomaterials .............................................................................................................................27

Structure-Property Relationships in Dental Nanocomposites........................................... 28

Multi-Modal Imaging and Quantitative Data Reduction

Methods for Regenerative Medicine ................................................................................ 29

Tissue Engineering Scaffolds ............................................................................................ 30

Combinatorial Methods for Rapid Screening of Biomaterials .......................................... 31
iv

Table of Contents

Materials for Electronics .........................................................................................................33

Characterization of Porous Low-k Dielectric Constant Thin Films..................................34

Polymer Photoresists for Next-Generation Nanolithography ........................................... 35

Organic Electronics...........................................................................................................36

Nanoimprint Lithography ..................................................................................................37

Nanometrology ........................................................................................................................39

Combinatorial Adhesion and Mechanical Properties:

Axisymmetric Adhesion Testing........................................................................................40

Combinatorial Adhesion and Mechanical Properties:

Innovative Approaches to Peel Tests ............................................................................... 41

Gradient Reference Specimens for Advanced

Scanned Probe Microscopy ..............................................................................................42

Wet Nanomanufacturing ...................................................................................................43

Characterization of Counterion Association with

Polyelectrolytes: Novel Flexible Template Behavior ....................................................... 44

Safety and Reliability ...............................................................................................................45

Ballistic Resistance of Polymeric Materials .....................................................................46

Polymers Division FY04 Annual Report Publication List ........................................................47

Polymers Division ....................................................................................................................59

Research Staff.........................................................................................................................60

Organizational Charts ..............................................................................................................69
1

Executive Summary

Executive Summary

The NIST homepage summarizes the key vision for

the National Institute of Standards and Technology

. . .working with industry to foster innovation, trade,

security and jobs. This vision guides the choices of

research in the Polymers Division. In this annual

report, we have tried to give you an update on our

current projects and a glimpse of some of the

scientific highlights of 2004.

Our researchers supporting the electronics materials

industry continue to have strong interactions with

industry, research organizations, and scientific peers.

International SEMATECH remains a strong supporter

of our work, pushing forward with next generation

low-k dielectric materials. Building on some previous

work with IBM, we have now partnered with

SEMATECH to extend our investigations of the

fundamentals of the lithographic process. This year,

we completed our work on dielectric metrology for

embedded passive devices and initiated two new

projects: one in organic electronics and the other

in nanoimprint lithography. Both technologies are

expected to play prominent roles in the future

generations of semiconductor electronics, and there

are tremendous scientific and technical challenges

to address before that promise is realized.

Following completion of our work on polyolefin

mass spectrometry, we returned to a focus on

quantitative mass spectrometry of polymers. Our

ultimate goal is a standard method for quantitation of

the absolute molecular mass distribution of polymers,

which would enable researchers to produce their own

reference standards. This year an interlaboratory

comparison has given us insight into ways to quantify

the accuracy and repeatability of matrix-assisted laser

desorption-ionization mass spectrometry (MALDI-MS)

in the identification of multiple end groups that result

from polymer synthesis. Our processing characterization

work continues to break new ground in rheology with

the recent observation of suppression of die swell for

extruded polymers blended with a small quantity of

multiwall carbon nanotubes.

Our biomaterials-related work continues to attract

attention on several fronts, from our collaboration

with the American Dental Association Foundation

on dental restorative materials to our 3-dimensional

structural/functional imaging techniques that

allow for in-situ imaging of cell growth in tissue

engineering scaffolds. To further our understanding

of the interface of materials with cell biology,

we are extending our imaging capabilities beyond

structure and function to chemistry, through

development of broadband coherent anti-Stokes

Raman scattering (CARS) microscopy. CARS

microscopy holds the potential to enable further

understanding in regenerative medicine by deciphering

metabolic state and cell type in-vitro. Other exciting

advances have been made in methodology for

evaluation of the biocompatibility of materials using

Quantitative Reverse Transcriptase Polymerase

Chain Reaction (QRT-PCR).

Our combinatorial and high-throughput researchers

continue to be recognized as pioneers and valuable

partners in accelerated materials research, and our

NIST Combinatorial Methods Center (NCMC)

continues to attract new industrial members.

The latest in the string of innovative approaches

has demonstrated the adaptation of microfluidic (μF)

technology to fabricate polymer molecule libraries

that are compatible with other high-throughput

measurement methods. In addition to this advance

in μF technology, we now have a μF method of

measuring interfacial tension in complex fluids. Our

work on adhesion has progressed with high-throughput

methods to enable rapid quantification of performance

through visualization of debonding mechanisms across

libraries of adhesive conditions.

This year we responded to some specific requests from

other government agencies including a collaboration

with NIST’s Office of Law Enforcement Standards

on long-term stability and durability of polymeric

materials for ballistic resistant armor (e.g., “bulletproof

vests”). Based on our expertise in composite fibers,

we are developing a minimally invasive technique to

test polymeric fibers from ballistic armor currently in

service. We hope to establish the critical links between

chemical structure, mechanical properties, ballistic

resistance, and long-term stability.

As usual, only a portion of our work is included in

this report, so please visit www.nist.gov/polymers

for more details. On our site, you can also download

copies of any of our publications.

As always, I welcome your comments.

Eric J. Amis

Chief, Polymers Division
2

Technical Highlights

Coherent Anti-Stokes Raman Scattering (CARS) for

In-Situ Chemical Imaging of Tissue Engineering Constructs

Design issues relating to bioactive devices for

regenerative medicine reflect the spatial and

chemical complexity of biological and materials

issues and their interactions. Tools developed

for the purpose of aiding understanding of these

systems must have sufficient discriminatory power

to sort out this complexity. We have introduced

a relatively simple broadband spectroscopic

microscopy based on CARS that can be used to

rapidly acquire volumetric, chemically-specific

images with submicrometer resolution.

Marcus T. Cicerone

Biological research in general could be significantly

 aided by a high-resolution, chemically sensitive

volumetric imaging method that allows rapid, non-invasive

study of processes on the tissue, cellular and sub-cellular

levels. The need for such a method is particularly

acute in the field of tissue engineering, where cycles

of cell-seeding and analysis can take months. Standard

analysis methods are labor intensive and destructive,

so multiple endpoint studies must be performed and

temporal correlation assumed. Non-invasive microspectroscopic imaging could alleviate many problems

associated with the evaluation of tissue scaffolds both

by allowing continuity of analysis on a single scaffold

construct, and by maintaining spatio-temporal information.

Our vision is the creation of a non-invasive microscopic

imaging technique that rapidly discriminates between an

arbitrary number of chemically distinct structures or

species in a spatially resolved way within a biological

system. We envision that this would be done without

staining or otherwise intrusively manipulating the system.

We expect that such a microscopy tool would have a

significant impact on the way in-vitro tissue-engineering

studies are carried out.

While our vision may sound fanciful, the basis

for such powerful and generally applicable chemical

discrimination was established many decades ago via

vibrational spectroscopy. Our contribution has been

to marry broadband vibrational spectroscopy, with

its inherent chemical resolving power, to a nonlinear,

multiphoton microscopy (CARS microscopy), which

has already been demonstrated to have significant utility

for non-invasively imaging biological systems, even in

the absence of significant chemical resolving power.

Microscopic coherent anti-Stokes Raman

scattering (μCARS) can answer important imaging

needs of the biological research community, including

relative non-invasiveness, rapidity, and chemical specificity.

CARS provides chemical specificity through its intrinsic

sensitivity to molecular vibrational transitions. CARS is

sensitive to the third order polarizability, χ(3), which has

nonresonant and resonant components, the latter being

related to the Raman scattering cross section. Therefore,

μCARS uses Raman (vibrational) susceptibility as a

contrast mechanism, but it is approximately 103 more

efficient than spontaneous Raman scattering.

Figure 1: Energy level diagram for single frequency CARS

process (solid vertical arrows) and broadband CARS (solid

and dashed vertical arrows).

The solid vertical lines of Figure 1 represent

transitions made by molecules in the “classic” CARS

scheme. Molecules in a sample of interest are promoted

to a specific energy E = h (wp – wS), where ωp and ωS

are the frequencies of the near infrared pump and

Stokes light pulses, respectively, and h is h/2π where h

is Planck’s constant. If that energy corresponds to a

particular excited vibrational state in the molecule, that

state is populated. A subsequent probe photon (also ωp)

promotes the vibrationally excited molecule to another

(higher) virtual state, from which it relaxes and emits

an anti-Stokes photon at a specific frequency, ωaS.

The flux of anti-Stokes photons detected is proportional

to the number of molecules initially prepared in the

targeted vibrationally excited state. To date, this

“classic” μCARS scheme has been used to acquire only

single-frequency or narrowband (200 cm–1) vibrational

information, and thus, chemical specificity is limited

to only one or two species simultaneously.

–

–
3

Technical Highlights

We have developed, and demonstrated for the

first time, a CARS microscope that yields vibrational

spectra over a 2500 cm–1 range. This method can give

chemically specific information for multiple species

simultaneously. Furthermore, information about subtle

changes in such things as metabolic state or phenotype

of cells, which are of interest when considering

cell-scaffold interactions, can be extracted from

these broadband vibrational spectra.

Figure 1 illustrates that the key to increased

bandwidth of vibrational sensitivity in CARS is an

increased bandwidth of the Stokes light. As our Stokes

light source, we have used continuum light generated

from ultrafast light pulses passed through a tapered

optical fiber. Our apparatus uses the 785 nm output

of a Ti:Sapphire oscillator (200 mW, 76 MHz, 150 fs

pulses) fed into a tapered nonlinear fiber, 9 mm long

with a 2 μm diameter waist to create a continuum that

spans the wavelength range (500 nm to 1100 nm).

A spectrally narrow portion of the same oscillator

output is used for the pump and probe light.

At a total optical power of 21 mW and 0.8 NA

focus, the photon flux density on the sample is

sufficiently low that we do not damage even rapidly

dividing live cells. At this low light level, we are able

to acquire reasonably good broadband spectra in about

20 ms. Image scanning is performed by moving a

sample through the focus of an objective using a

motorized microscope stage. We employ an intensified

CCD camera to detect the anti-Stokes light after it

has been spectrally dispersed by passing through a

spectrograph.

Figure 2a is a first demonstration of this method;

it is an image of a tertiary polymer containing equal

parts of polystyrene (PS), poly(methyl methacrylate)

(PMMA) and poly(ethylene terephthalate) (PET); the

polymer blend was annealed at 250 °C for 120 s, then

melt-pressed at this temperature. Spatially-resolved

spectra were obtained by broadband μCARS, and

pseudo-colors were assigned to each pixel based on the

primary polymer component — red, green, and yellow

for PMMA, PS, and PET respectively. The reference

spectra used for identification are plotted in Figure 2b,

with an arbitrary vertical shift applied for clarity.

The primary polymer component within an image

pixel (i.e., the pixel “identity”) was determined as

follows. First, the CARS spectra from the image and

the reference spectra were systematically normalized by

the nonresonant background. Next, a dot product was

calculated between the spectrum belonging to the pixel

in question and the sections of each reference spectrum

enclosed by the hatched boxes in Figure 2b. The dot

product yielding the greatest value of the three determined

the assigned polymer identity for that pixel. The reference

spectra sections were amplitude-scaled such that a dot

product of each with itself gave the same value. Using

this procedure, we could assign a polymer identity to

each pixel with a standard uncertainty of 0.01.

Figure 2: Panel a) — Pseudo-color image, generated with broadband

CARS microscopy, of phase-separated polymer blend including equal

parts of PMMA, PS, and PET. The colors red, green and yellow

correspond to PMMA, PS, and PET respectively. Panel b) — Reference

spectra used for computing dot products with the spectra from each

pixel in panel a. The hatched boxes indicate spectral regions that

were used for computing dot products (see text for discussion).

An account of this work has been accepted for

publication in Optics Letters. We will also report on the

new method at the 2004 “Vibrational Spectroscopy” and

“Biomedical Imaging” Gordon Research Conferences

(2004), and the August 2004 American Chemical

Society National Meeting.

We gratefully acknowledge Dr. Lee Richter for his

interest and input. We also thank Dr. John Lawall and

Dr. Tsvetelina Petrova for helpful guidance with regards

to continuum generation. This work was funded in part

by NIH Grant # 1 R21 EB002468-01.

For More Information on this Topic

T.W. Kee (Polymers Division, NIST)
4

Technical Highlights

Use of Reverse Transcriptase Polymerase Chain Reaction

(RT-PCR) to Measure Cellular Responses

The goal of this work was to develop a set of

genetic markers of cellular responses to provide

improved measurement of biomaterial performance.

This set of markers gives information on important

phenomena such as cell proliferation, matrix

production, and inflammation. We have developed

genetic tests based on Quantitative Reverse

Transcriptase Polymerase Chain Reaction

(QRT-PCR) for assessing these complex

cellular responses.

LeeAnn Bailey and Matthew L. Becker

The interface between the biomaterial and the cell is

a critical point of interaction for tissue-engineered

products. The nature of both the physical and chemical

interactions can cause cells to transmit a variety of

critical biological signals. In response to external stimuli,

cells initiate a genetic response to determine which

regulatory pathway the cell will traverse (Figure 1).

These pathways include chronic and acute inflammation,

differentiation, proliferation, and extracellular matrix

production, which ultimately affects the well-being

of the cell and determines the success of the

tissue-engineered scaffold. We have developed a

set of genetic tests based on Quantitative Reverse

Transcriptase Polymerase Chain Reaction (QRT-PCR)

for assessing complex cellular responses.

measured during the exponential phase of the

amplification reaction (Figure 2). The copy number

is obtained by extrapolating to a standard gene curve

of known concentration and copy number to yield

quantitative data. The assay also includes the analysis

of mRNA that does not change in relative abundance

(18S), which serves as an internal control.

Figure 1: Scaffold interactions can lead to cellular inflammation,

differentiation, proliferation, and extracellular matrix production.

In a typical experiment, mRNA is extracted from

a cell population following a defined incubation period

with the substrate. Using a reverse transcriptase (RT)

enzyme, mRNA is converted to the cDNA template

necessary for amplification. Then the cDNA, gene

specific primers, a DNA polymerase, and a fluorescent

moiety are utilized to amplify and label the amplicon

generated. The gene product accumulation is then

The Biomaterials Group in the Polymers Division

has successfully created a model system to evaluate the

biocompatibility of materials in-vitro using QRT-PCR.

The method has been adapted to measure both DNA

and RNA sequence levels present in cellular populations

and determined to be substrate independent. Current

technique sensitivities can detect one gene copy from

a single cell and provides accurate, reproducible

measurements regarding the genetic profile of the cell

at a given time point. Table 1 includes a brief list of

the numerous biological processes and specific gene

markers being utilized in ongoing research.

Table 1: A brief list of the gene specific markers

utilized in the Biomaterials Group’s current

research efforts and their corresponding

biological processes

Process Gene Marker

Inflammation IL-1β, TNF-α

Matrix Production Fibronectin, Collagen I & II, Actin

Differentiation Aggrecan, Osteopontin, Osteocalcin

Figure 2: RT-PCR is based on the detection of a fluorescent

species that binds to double-stranded DNA produced

proportionally during PCR amplification cycles.
5

Technical Highlights

Recently completed QRT-PCR studies have

documented quantitatively the inflammatory response of

murine macrophages that have phagocytosed poly(methyl

methacrylate) (PMMA) microspheres and/or been

exposed to lipopolysaccharide (LPS). The studies

have yielded great insight regarding the initiation and

propagation of tumor necrosis factor-α (TNF-α)

and interleukin-1β (IL-1β) cytokine profiles. The cell

populations treated with LPS or PMMA microspheres

singly resulted in an elevation of cytokine levels compared

to the untreated control. RAW 264.7 cells incubated with

LPS and PMMA particles demonstrated a synergistic

effect by producing a marked increase in the level of

cytokine expression, over control levels.

1) Fibronectin, collagen, and actin regulation in tissueengineered scaffolds, thin films, and polymer blends.

2) Inflammatory responses to dental adhesives and

bonding resins.

3) Inflammatory responses to metal alloy implant

materials, both in particulate and solid form.

Figure 3: Gene copy number of IL-1β and TNF-α after 8 h of

incubation with poly(methyl methacrylate) microspheres (PMMA),

lipopolysaccharide (LPS), both PMMA and LPS, and an untreated

control, a. The photos on the right depict untreated RAW 264.7

murine macrophages, b, and macrophages phagocytosing PMMA

microspheres, c.

Figure 4: Shell cross-linked (SCK) nanoparticles functionalized

with different amounts of the protein transduction domain (PTD)

of HIV-1 Tat causes statistically significant increases in IL-1β

production after 24 h of incubation that is functionalization and

concentration dependent.

There are numerous other applications that QRT-PCR

is currently being applied to both inside and outside the

Polymers Division. Application of nanotechnology in

healthcare is generating significant enthusiasm, but little

is known about the consequences of nanoparticles and

functionalized nanostructures on biological systems.

One question of critical importance concerns the

inflammatory effects of nanometer-scale materials.

The inflammatory response to peptide functionalized

shell cross-linked (SCK) nanoparticle was found to be

dependent, with respect to functionality and concentration.

These studies have laid the foundation for the additional

measurements of other nanoparticle systems, which

can be coupled to a myriad of biologically relevant

peptides or pharmacological agents.

Additionally, QRT-PCR technology has been utilized

to investigate the genetic expression profiles of several

biological model systems such as:

In summary, QRT-PCR is a high-throughput, versatile

measurement tool that can quantify an extensive range

of genetic measurements in tissue-engineered products.

For More Information on this Topic

L. Bailey, N. Washburn, C.G. Simon, E. Chan,

and F.W. Wang, “The Quantification of Inflammatory

Cellular Responses Using Real-Time Polymerase Chain

Reaction (RT-PCR),” Journal of Biomedical Materials

Research 69A(2), 305–313 (2004).

M.L. Becker, L.O. Bailey, and K.L. Wooley, “Peptide

Derivatized Shell Crosslinked (SCK) Nanoparticles.

2) Biocompatibility Evaluation,” Bioconjugate

Chemistry, in press.

Collaborators

N.R. Washburn, J.C. Cooper (Polymers Division,

NIST); K.L. Wooley (Washington University);

J. Kohn (Rutgers)
6

Technical Highlights

Profiling the Photoresist-Liquid Interface: Fundamentals

for Immersion Lithography and Polymer Dissolution

Recent advancements in the semiconductor

industry have resulted in new problems involving

the photoresist-liquid interface. For immersion

lithography, the water profile within a resist film

impacts pattern quality from changes in photoacid

generator diffusion or optical transparency.

For the development step, where a latent image

is realized into the final structure, an improved

understanding of photoresist swelling and

dissolution mechanisms is needed to address

stringent line-edge roughness requirements.

Data from neutron reflectivity measurements

provide critical insight needed to understand

and optimize next-generation photoresists and

process strategies.

Bryan D. Vogt and Vivek M. Prabhu

Introduction

Polymer thin film photoresists comprise the materials

foundation for the production of semiconductor

devices with nanoscale dimensions. The extension of

optical methods has been problematic due to challenges

arising from the implementation of shorter exposure

wavelengths. The past focus of the semiconductor

industry has been the development of sufficiently

transparent photoresist materials for future exposure

sources. However, future progress requires depth

profile information at the photoresist–liquid interface,

due to the emergence of immersion lithography and

the increased influence of the photoresist development

process on lithographic performance.

Using neutron reflectivity (NR), NIST successfully

quantified the profile of water and aqueous base

counterions in model photoresist films. NR provides

structural information regarding the composition

profile normal to the thin-film surface with isotopic

selectivity between protons and deuterium. Selective

deuteration of components in the system allows for

the quantification of water or counterion distribution

within photoresist films despite the negligible

differences in physical density. This data provide

critical insight needed to refine models for immersion

lithography and polymer dissolution.

Immersion Lithography: Water Profile

Recently, immersion lithography has emerged

as the key strategy to extend existing optical tools.

A liquid, such as water, is placed between the lens

and photoresist thin film to enhance resolution.

The industry anticipates using immersion lithography

for production in 2007 at the 65 nm node. The role of

liquids in contact with photoresist films is important;

not only for component leaching and contamination,

but also due to the detrimental influence of trace levels

of water on the reaction and diffusion of photoacid

generators. Additionally, a non-uniform water profile

within thin films leads to incorrect assumptions

regarding the transmission and reflection at the

photoresist–anti-reflective coating interface.

Figure 1 shows the measured volume fraction

profile of water versus the distance from a

trimethylsilane-primed silicon oxide interface.

Far from the substrate, the 248 nm photoresist,

poly(4-tert-butoxycarbonlyoxystyrene) (PBOCSt),

shows bulk water absorption near 2.5 %. However,

significant deviations occur near the interface.

An excess of water, up to 17 %, extends 40 Å from

the substrate. This enriched interfacial water was

previously unknown and unaccounted for.

In contrast, a depletion of water was observed for

poly(4-hydroxystyrene) (PHOSt), the developer soluble

resist, even though the bulk of the film absorbs 25 %.

This depletion indicates the interface cannot accommodate

excess water. It appears that the relative hydrophobicity

between polymer and substrate controls the amount of

interfacial water.

Figure 1: Volume fraction of water distributed near the

PBOCSt/HMDS treated substrate during immersion, as

determined by neutron reflectivity. The excess of water at the

substrate reaches a maximum concentration of 17 % by volume.

Inset: Dependence of initial film thickness on the total film

swelling for two model photoresists in thin and ultrathin films.
7

Technical Highlights

The total film swelling is also observed to be a

function of the initial thickness and interfacial water.

For thinner resist films the interfacial water dominates

the swelling as shown in the inset to Figure 1 for

PBOCSt and PHOSt. For these different resists, the

swelling becomes similar for ultrathin films with

thickness less than 200 Å. The data are consistent with

an interfacial water thickness and content for each film

thickness. The interfacial concentration is strongly

dependent upon the surface chemistry, but relatively

independent of the photoresist material or film thickness.

Dissolution Effects: Aqueous Base Profile

The development step of a latent image in an

aqueous base contributes significantly to undesirable

line-edge roughness (LER). There is a strong need

for improved dissolution models incorporating

photoresist-developer interactions. A key component

is the depth profile of the aqueous base counterion

through a photoresist film because it controls the

dissolution mechanisms that lead to unacceptable

LER. We provided the first direct measurement of

the aqueous base distribution (tetramethylammonium

hydroxide) (TMAH) within the film. These

measurements quantify the extent of developer

penetration and the influence of ionization on the

response of the photoresist to the developer solution.

We used a zero-average contrast (ZAC) experiment

where the neutron scattering length density of a thin

film of poly(norbornene hexafluoroisopropanol)

(PNBHFA), a model 157 nm photoresist, is matched

to the developer solution with a D2O/H2O mixture.

As shown in the schematic of Figure 2, the contrast

matched film and solvent (equal color) eliminates

neutron contrast at this interface. However, when base

(d12–TMAH) enters the film, the reflectivity contrast

is enhanced. These changes allow quantification of

both film swelling and the base profile through the film.

throughout the entire film rather than gradually through

the film. In addition, a depletion of base was observed

at the substrate. The film-solution interfacial width

increases with higher base concentration. These

measurements show that ionization-induced swelling

occurs at the dissolution front. At even higher base

concentrations, the photoresist film dissolves quickly.

Understanding the transition from swelling to rapid

dissolution with base concentration will provide

guidance into developer-induced roughness.

Figure 2: Schematic of the zero-average neutron reflectivity

experiment. The contrast between the film and solvent are equal,

only the enrichment of deuterated aqueous base within the film

provided the reflectivity enhancement.

Figure 3: Volume fraction profiles of d12-TMA+ within the

PNBHFA film. The aqueous base profile illustrates the enhanced

swelling and content within the thin film with higher equilibrating

base concentration.

These base profilometry experiments were followed

by a deswelling step by rinsing with pure water. The

rinse kinetically traps base within the film where it could

contaminate other processes during device fabrication.

NR measurements provide new information about

the liquid–photoresist interface needed to improve

current models of dissolution. In future work, we will

examine the effects of liquid–photoresist interactions

on surface roughness with atomic force microscopy

measurements of surface features.

For More Information on this Topic

C. Soles, M. Wang, C. Wang, R. Jones, W. Wu,

E. Lin (Polymers Division, NIST); S. Satija (NCNR,

NIST); D. Goldfarb, M. Angelopoulos (IBM

T.J. Watson Research Center); H. Ito (IBM Almaden

Research Center).

B.D. Vogt, et al., “Water immersion of model

photoresists: Interfacial influences on water concentration

and surface morphology,” J. Microlithography,

Microfabrication, and Microsystems, in press.

The volume fraction of d12–TMA+ is plotted

versus distance from the substrate in Figure 3 for

four different equilibrating concentrations of base.

The change in the counterion profile illustrates the

advancement of the swollen solid front. A key finding

was that the film expansion proceeds via base transport
8

Technical Highlights

Embedded passive devices require high dielectric

constant hybrid materials consisting of filled

polymers to advance miniaturization and

functional performance of high-speed electronics.

New metrology methods were developed to address

the needs of the electronics industry. Two test

methods, a Test Method for Dielectric Permittivity

and Loss Tangent of Embedded Passive Materials

from 100 MHz to 12 GHz and a Test Method for

Dielectric Withstanding Voltage were completed and

have received wide acceptance by industry as new

test methods to accelerate the development of

embedded passive device technology.

Jan Obrzut

Introduction

Continuous reductions in the electrical charge

required to drive logic gates and storage cells

have resulted in tremendous progress in miniaturization

and density of integrated circuits. However, enhanced

functional performance increasingly depends on

passive components such as capacitors, resistors,

and inductors, where the dielectric permittivity and

impedance characteristics of the material control spatial

dimensions, time scale, speed, shapes and amplitude

of electronic signals. Passive devices have not shrunk

in size as rapidly as active devices and occupy an

increasingly larger area and mass fraction of electronic

subassemblies.

Dielectric Metrology and Test Methods Supporting

Embedded Passive Device Technology

Significant advantages arise if passive devices are

integrated directly into the circuit board as embedded

passive devices rather than discretely attached with

automated assembly. These include much thinner and

sleeker electronics such as cell phones, decreased

manufacturing costs, better electrical performance,

and enhanced design flexibility. Companies including

Gould, Shipley, Ohmega, MacDermid, DuPont, Motorola,

Oak-Mitsui, 3M, and Sanmia have devoted millions

of dollars to advance this technology in an effort that

represents a huge transition for the electronics industry.

High dielectric constant hybrid materials

consisting of filled polymers are essential for advancing

miniaturization and functional performance. There

are significant challenges in developing new thin-film

materials that require enhanced electrical performance

characteristics, such as impedance and high dielectric

constant (high-k), in order to operate at higher

microwave frequencies and at increased voltage

strengths. Consequently, new metrology and test

methods are needed to address the specific behavior

of thin film specimens and to better understand the

relation between functional performance and the

structural attributes of the materials.

The materials and testing requirements for

Embedded Passives Technology are outlined in

the National Electronics Manufacturing Initiative

(NEMI) 2004 Roadmap. A need for new standard test

methods for embedded materials was identified by the

Association Connecting Electronic Industries (IPC),

Roadmap 2005 Outlook Update, IPC Embedded Passive

Device Standard Committee D-39. In partnership with

industry, NIST chaired a test methods task group to

communicate and collaborate with industrial partners.

This year, two new test methods were accepted and

will be used extensively by industry to accelerate

implementation of this new technology.

Dielectric Permittivity and Loss Tangent

The development of new thin-film materials that

exhibit enhanced electrical performance characteristics,

such as impedance and high dielectric constant (high-k),

requires a broadband measurement technique for

measuring permittivity at microwave frequencies

(100 MHz to 12 GHz). Instead of expensive, single-test

microwave strip test structures, NIST forwarded a

general measurement strategy of incorporating a thin

passive film material into a device that is comprised

of a capacitive or resistive termination in a transmission

line. The technique is based on the observation and

theoretical analysis of the fundamental mode propagating

at high frequencies in thin film dielectrics that terminate a

coaxial air-filled transmission line. The development of

the method involved nearly 50 active industrial partners

and was reviewed by more than 300 other parties.
9

Technical Highlights

An example measurement of the dielectric constant

for a high-k material obtained from DuPont is shown

in Figure 1. We guided the design of the test protocol

and made arrangements with co-sponsoring member

companies for round robin evaluation of the measurement

method. The work resulted in a test document “Test

Method for Dielectric Permittivity and Loss Tangent

of Embedded Passive Materials from 100 MHz to

12 GHz,” which has received wide industrial acceptance

and recommendation as a new standard test method.

This new capability to measure the dielectric

properties at high frequencies for a wide range of

dielectric permittivity values is also used to quantify

dispersion, alignment, and structure in hybrid materials.

For example, we demonstrated that composites of

organic polymer resins filled with ferroelectric ceramics

exhibit a dominant intrinsic high-frequency relaxation

behavior. Such dielectric properties are beneficial in

enhancing performance of processors and logic devices.

Dielectric Withstanding Voltage

The dielectric breakdown of thin film materials is also

a significant issue in embedded passive devices. Due to a

thin film configuration, nonlinear effects may be activated

at moderate bias levels and contribute to the dielectric

breakdown. A non-linear dielectric measurement

methodology was developed and applied for testing

passive materials at high electric fields and voltages.

NIST-developed experimental set-up and

testing procedures demonstrated the unambiguous

determination of the dielectric withstanding voltage

of embedded passive materials. In contrast to

conventional procedures, the specimen voltage and

current are determined as complex quantities from the

corresponding time-resolved voltage waves. The new

testing procedure represents an extension compatible

with the existing standard test method, but is better

suited for capacitive and resistive thin film materials.

The specimen impedance and the loss tangent of

the material can be determined by performing complex

algebra calculations. It was found that thin-film

materials for embedded passives do not exhibit a

flat impedance characteristic, as is the case for

conventional dielectrics, but the impedance sharply

decreases with increasing voltage. The voltage

withstanding condition may be attributed to a voltage

range where the impedance characteristic remains

insignificantly affected by the applied voltage. An

equivalent impedance comparison indicates that high-k

organic composites can withstand only a small fraction

of the conventional dielectric withstanding voltage.

The NIST-developed procedure of recording and

analyzing waveforms also allows the evaluation of

specific characteristics of materials that cannot be

readily evaluated with conventional techniques.

This measurement procedure is especially suitable

for detecting and analyzing non-linear dielectric effects

that can result from polarization reversal and rectifying

barriers. Such effects may appear at relatively low

voltages in nano-sized interfaces, composites, and

sub-micron thin dielectric films that are of interest

to emerging technologies.

For More Information on This Topic

A. Anopchenko, K. Kano (Polymers Division,

NIST); D. McGregor, G.S. Cox, J. Felten (DuPont);

D. Fritz (MacDermid); T. Bergstresser (Gould

Electronics); K. Fjeldsted (Electro Scientific Industries);

R. Crosswell (Motorola); C. Vanderpan (UL);

R. Whitehouse (Sanmina-SCI)

J. Obrzut and A. Anopchenko, “Input Impedance

of a Coaxial Line Terminated with a Complex Gap

Capacitance — Numerical and Experimental Analysis,”

IEEE Transactions on Instrumentation and

Measurement, 53 (4), August (2004).

J. Obrzut and K. Kano, “Measurement of Complex

Impedance at High AC Voltages using Waveforms,”

IEEE, IMTC/2004 3, 1994–1997 (2004).

J. Obrzut, A. Anopchenko, K. Kano, and H. Wang,

“High Frequency Loss Mechanism in Polymers Filled

with Dielectric Modifiers,” Mat Res. Symp. Proc. 783,

B3.5-8 (2003).

J. Obrzut and A. Anopchenko, “High frequency

input impedance characterization of dielectric films

for power-ground planes,” IEEE Transactions on

Instrumentation and Measurement 52, 1120–1124 (2003).

Figure 1: Dielectric constant of high-k polyimide-based composite

films determined according to the Standard Test Method. (HK10 is

a 25 μm thick composite; HK11 is a 14 μm thick composite).
10

Technical Highlights

High-throughput (HT) tools to measure

properties of complex fluids will greatly facilitate

formulations science. Industrial members of the

NIST Combinatorial Methods Center viewed a

new HT method to measure interfacial tension

as a primary need for product development.

We have addressed this challenge with a novel

microfluidic, high-throughput strategy to

materials research and development.

Steven D. Hudson, João T. Cabral, and

Kathryn L. Beers

By developing microfluidic (μF) instrumentation

to measure the behavior of polymers in complex

fluids, we aim to demonstrate exciting new approaches

to formulation science. With fast, flexible methods of

designing and assembling milli-scale models of emulsion

or colloid processing tools, high-throughput screening

and optimization of new materials and discovery of

new applications can be achieved across multiple stages

of process development. Chemical suppliers and their

customers will be able to obtain more and higher quality

data relevant to the polymer additive properties critical

to their business.

Most current μF technology is directed toward life

science applications with devices designed primarily for

low viscosity, aqueous solutions. We have developed

a soft lithographic technique, which imparts solvent

resistance to our devices and facilitates the integration

of both aqueous and organic media. Multiple

compositions can be evaluated by varying the input

of either phase. Combinatorial μF systems can then

be developed to measure viscosity, interfacial tension,

and stability of emulsions in an automated and

high-throughput manner. Our systems allow multiple

feedstocks to be mixed in a range of compositions and

have their above-mentioned properties measured over

a range of temperatures. We envision a combinatorial

factory in which materials synthesis, characterization,

and processing are integrated.

As a first step towards this goal, and in consultation

with industrial sponsors from ICI National Starch and

Procter and Gamble, we are developing an instrument

to measure interfacial tension of water/oil systems that

is accurate within a few percent over a wide range of

interfacial tension (from 0.1 to 50 mN/m). Moreover,

microfluidic technology is well-suited to kinetic analysis,

since the properties of the fluid can be analyzed at different

points along the channel. In this way, dynamic interfacial

properties associated with interface age, as well as

quasi-equilibrium properties, are accessible.

High-Throughput Measurement of Interfacial Tension

We have implemented the HT instrument using

a microfluidic device connected to fluid pumps and

mounted on a microscope equipped with a fast

camera. Experiment and data handling is computer

controlled, featuring a real-time image analysis

program. The device is fabricated using a novel rapid

prototyping (RP) technique reported earlier and takes

advantage of frontal photopolymerization (FPP) to

generate 3-dimensional structures. This contact

photolithography technique allows for the control of

both lateral and vertical dimensions of patterns imaged

on a negative polymer resist, which is then replicated

on a transparent elastomer (PDMS). Assisted by flow

simulations, we have devised a μF device geometry

capable of drop formation, mixing of components,

and drop acceleration and deformation (Figure 1).

Figure 1: Microfluidic prototype for measuring interfacial

tension in immiscible fluids, displaying a combinatorial droplet

mixer, acceleration junctions, and a series of extensional flow

constrictions. This 3-dimensional device is fabricated using

a novel rapid prototyping technique based on frontal

photopolymerization and is sealed against a microscope glass

slide. Inset: Schematic microchannel design. Fluids 1a and b

are mixed together and injected as drops into immiscible stream 2.

These drops are then fed by 3a and 3b into channel 4 for analysis

and measurement. The constrictions in channel 4 accelerate

and therefore stretch the drops. Multiple constrictions permit

measurement at different interface age.

A custom-built LabVIEW program drives fluid

pumps, analyzes images in real time (Figure 3) and

computes drop shape, velocity, and fluid extension

rate. Following Taylor’s classical theory for drop

deformation in extensional flow fields, we compute

the material rate of change of the drop deformation D

(defined in Figure 2):

D D D D − + = − = τ ε

η

τ & 2 ˆ 3

5

steady dt

d . 
11

Technical Highlights

Figure 2: Freeze-frame image of drops flowing left to right in an

extensional flow gradient. When the drops leave the constriction

(the channel walls appear as slanted lines in the left half of the

image), the flow decelerates in proportion to the change in

cross-sectional area. The drops, which are generated periodically

in time, therefore, become closer together. This deceleration

corresponds to a stretching in the transverse direction; note that

the drops at the left side are stretched vertically, and their

deformation decays as they pass to the right.

Figure 3: LabVIEW interface used to control the instrument

and record data.

where ao is the undeformed drop radius, hc is the

continuous phase viscosity, ε& is the shear rate, and

ηˆ is the relative viscosity of the drop.

This rate is directly proportional to interfacial tension σ.

Specifically, the drop relaxation time τ is:

Figure 4: a) Simulated and b) experimental analysis of drop

deformation upon departure from the channel constriction.

The radius ao, deformation D and velocity u of the drops are

measured directly by image analysis, at a rate of > 100 data

points/s. The extension rate ε is simply the gradient in the velocity

du/dx. When the data is plotted in this way, the slope is directly

proportional to the interfacial tension. For water in oil, the

tension is (31.8 ± 0.8) mN/m, which is in accord with pendant

drop measurement (32.0 mN/m). For the surfactant

(EO19PO30EO19) aqueous solution in oil, the tension is 7.2 mN/m.

In this experiment, the interface age is approximately 1 s.

For More Information on this Topic

E.J. Amis, P.R. Start (Polymers Division, NIST);

Focus Project Members: ICI National Starch;

Procter and Gamble

J.T. Cabral, S.D. Hudson, C. Harrison, and

J.F. Douglas, “Frontal Photopolymerization for

Microfluidic Applications,” Langmuir, in press.

The current measurement rate may exceed 100 data

points/s and is dependent on drop formation and image

acquisition rates.

( )( )

( ) σ

η

η

η η τ c o a

40 ˆ 1

2 ˆ 3 19 ˆ 16

+

+ + =
12

Technical Highlights

Advanced material products incorporate highly

designed polymer molecules, yet the effect of

molecular parameters on end use properties

is not understood. From both a scientific and

an industrial perspective, there is a need for

simple and economic synthetic methods that

generate combinatorial polymer libraries that

systematically vary molecular mass, architecture,

and molecular composition. New methods at the

NIST Combinatorial Methods Center (NCMC)

enable the fabrication of polymer molecule

libraries that are compatible with high-throughput

measurement methods.

Kathryn L. Beers and Tao Wu

For a large number of specialty polymers, the

properties critical to their end use (e.g., products

ranging from personal care to nanotechnology

applications) depend upon molecular variables such as

chain sequence and composition, branching, and molecular

mass. Often times, as in the case of the bicontinuous

microstructures found in some block copolymers, the

target variable space is narrow and difficult to define

precisely. Tools exist to characterize these key properties

in a high-throughput manner; however, there are few

synthetic techniques that complement these measurement

methods without capital-intensive automation. Moreover,

in practice, current parallel polymer synthesis processes

generally involve specimen volumes that are much

larger than required for the screening tests, resulting

in unnecessary chemical waste and over-use of

expensive monomers.

As part of the polymer formulations project at

NIST, new synthetic platforms are being developed for

the fabrication of molecular gradient libraries that meet

these challenges. Our approach leverages microfluidic

technology to control and confine liquid chemical

environments on the microscale. Using this technology,

we have produced devices to achieve solution phase,

surface-grafted, and suspension polymerizations in a

manner that produces gradients in molecular properties

in a controlled and addressable manner.

Figure 1 shows the first example of our new synthesis

platform: a controlled radical polymerization (CPR)

chip. Fabrication of the CPR chip uses conventional

photolithographic techniques to pattern a thiolene-based

optical adhesive between two glass slides, thus creating

channel structures. Solutions of monomer, initiator, and

catalyst are introduced through input ports at one end of

Polymer Library Fabrication Techniques Using

Microfluidic Technology

the device and actively mixed with an enclosed spin bar.

Controlled polymerization in a main channel is achieved

through an atom transfer mechanism, where molecular

weight is tailored by the ratio of monomer to initiator and

the reaction time. By maintaining plug flow in the channel,

controlling the stoichiometry of the reagents (input),

and the flow rate of the solution through the channel, a

polymer product with a predictable, continuous gradient

in molecular weight and low polydispersity is produced.

We validated polymerization kinetics in the CRP chip

against published cases of synthesis carried out in

large-scale reaction flasks.

Whereas conventional techniques yield grams of a

single material, the CRP chip produces microgram-scale

material libraries that exhibit a systematic change in

molecular properties. Accordingly, this technique is

extremely powerful for optimizing materials with a

narrow target molecular parameter space, or for

developing new materials with expensive precursors,

such as proteins and other biomolecules — all with

minimal waste. Products of the CRP chip are neatly

matched to the scale and design of NCMC methods to:

1) prepare gradient thin films for solid materials property

measurements (e.g., modulus, adhesion,

microstructure); and

2) gauge solution properties (e.g., viscosity, stability)

through other fluidic devices being developed in the

Center (see Polymer Formulations project in

Advanced Manufacturing Processes).

Figure 1: a) CRP chip for producing well-defined polymeric

materials tuned by flow rate and input stoichiometry; b) SEC data

for polymers produced at different flow rates.
13

Technical Highlights

 Another of our microfluidic devices exploits

plug flow to achieve molecular gradients of surface

grafted polymers. Microchannel confined surface

initiated polymerization (μSIP; Figure 2) employs a

shallow channel (≈ 300 μm deep), formed through a

patterned polydimethylsiloxane (PDMS) stamp, to

confine a solution of monomer and catalyst over an

initiator-functionalized silicon substrate. The result is a

polymer grafted surface (brush) with geometry determined

by the channel design and a gradient in molecular

properties determined by the solution flow rate.

Several key features of μSIP illustrate its utility for

combinatorial library fabrication.

1) The surface in contact with the PDMS stamp retains

initiating capacity after the stamp has been removed,

as do grafted polymers synthesized through an Atomic

Transfer Radical Polymerization (ATRP) route.

Accordingly, complex graft copolymer libraries

can be built through sequential iterations of μSIP.

2) Utilizing multiple channels, it is possible to pattern

the same surface with multiple brush configurations,

as flow and stoichiometry conditions can be varied

from channel to channel.

3) Confined gradients formed inside microchannels

enable fabrication of grafted libraries of both statistical

copolymers and gradient (tapered) block copolymers.

As a result, μSIP represents a significant

improvement over existing techniques for grafting

polymers from surfaces. Moreover, it enables

fabrication of combinatorial substrates that could play

a critical role in nanomaterials development, since

many routes for nanofabrication (e.g., self assembly)

are extremely sensitive to substrate chemistry.

Moreover, we envision μSIP to be a useful tool

for nanometrology. For example, we intend to

employ these techniques toward the fabrication of

micropatterned substrates useful for the calibration

of new scanned probe microscopy (SPM) methods

Figure 2: a) Schematic of microchannel confined surface

initiated polymerization (μSIP) used to produce surface grafted

polymer gradients. b) Image of a grafted polymer molecular mass

gradient and a patterned substrate prepared using μSIP.

(see Combinatorial Gradient Reference Specimens

for Advanced Scanned Probe Microscopy project

under Nanometrology).

Our third device example concerns the preparation

of polymer colloids and droplets via suspension

polymerization in microfluidic channels (Figure 3).

Indeed, these synthetic routes represent the most

important methods used by industry. In this respect,

our thiolene-based devices represent a major advance

since they enable the creation of organic (hydrophobic)

droplets in a hydrophilic (e.g., water) matrix. This is a

key requirement for reproducing necessary conditions

for colloidal and suspension polymerization routes in

microchannels, a major (unmet) challenge for channels

fabricated from PDMS. Several preliminary devices

have been designed to prepare and polymerize oil

droplets in an aqueous continuous phase (Figure 3).

In current work, we aim to polymerize organic phase

droplets to form gradients of polymer microbeads.

Figure 3: A device that produces, polymerizes and characterizes

polymer colloids is one of the projects future directions. This device

shows an important NIST-developed milestone, two-component

toluene droplets suspended in an aqueous continuous phase.

Each of the three synthetic methods described above

has unique advantages including small specimen volumes,

the ability to make molecular gradients, and the type of

polymers (solution, block, graft, colloidal) they produce.

These methods are designed to interface with existing

NCMC methods including solution blending, rheological

and interfacial tension measurements, and gradient thin

film deposition high-throughput solid characterization and

microstructure analysis. As a part of the combinatorial

and high-throughput toolset at NIST, the ability to prepare

molecular gradients in a variety of forms is a fast,

accurate, and inexpensive resource to prepare many

important polymer libraries.

For More Information on this Topic

K.L. Beers, T. Wu, C. Xu, Z.T. Cygan, Y. Mei,

M.J. Fasolka, E.J. Amis (Polymers Division, NIST)
14

Technical Highlights

MALDI-MS Interlaboratory Comparison of Polymer Mixtures

Five gravimetric mixtures of two polystyrenes

with matched molecular masses but with different end

groups, –H and –OH, were created. The challenge for

the participants was, without knowing the gravimetric

values, to determine the mass fraction of each polymer

in each mixture. Difficulties to overcome included

different ionization probabilities of the two polymers

and finding small peaks in background noise for species

that are in the minority in the mixture. Fourteen labs

from 5 countries participated: 6 industrial, 4 academic,

and 4 government laboratories.

The PS syntheses were both initiated with butyl

initiator. One was terminated with H (PSH) and the

other was terminated with CH2CH2OH (PSOH).

These end groups are separated by 44 u and 60 u in

the mass spectrum and are well resolved (Figure 1).

Five mixtures of these were made up with mass ratios

between approximately 95:5 to 10:90 PSOH:PSH.

Nuclear magnetic resonance (NMR) and FourierTransform infrared (FTIR) spectroscopies conducted

at NIST confirmed the gravimetric mass ratio. The

existence of a small amount of PSH in the as-received

PSOH material was evident in our MALDI-MS analysis.

NMR gave between (4 to 9) % PSH polymer in the

PSOH-material. This is close to the value obtained

from the initial MALDI-MS analysis performed at NIST.

Each participating laboratory was asked to perform

MALDI-MS on each of the five mixtures using two distinct

protocols: one using all-trans retinoic acid with defined

concentrations of matrix:analyte:salt and a second protocol

defined by the user as their preferred method for analyzing

polystyrene. Each laboratory was asked to report two

repeats of each protocol for each mixture to check for

intralaboratory variability. Each laboratory was asked to

report the estimated ratio of the mass of PSH to the mass

of PSOH in each mixture and return data sets listing mass

versus the integrated peak area of the mass spectra.

The analysis of the data revealed a strong

variation among laboratories. This was seen in our

first interlaboratory comparison as well. The effect

of instrument manufacturer on the data was not

significant. But the difference between acquiring

mass spectra in the linear and the reflectron mode of

operation resulted in significant variation in the end

group fractions. The analysis of variance showed no

significant influence of the sample preparation protocol

on the fraction of PSOH in each mixture.

The accuracy of the instrument calibration of

each laboratory was assessed by calculation of end

group mass. In our first interlaboratory comparison,

calibration varied more widely than anticipated. We

would expect the calibration of most time-of-flight

mass spectrometers in this mass range to be off by less

than 3 u. Some laboratories showed calibrations off by

Polymer synthesis often results in impure

products, containing multiple end groups, due

to the synthesis process itself or the presence

of impurities. Identification and quantification

of these end groups and impurities is important

because they influence polymer properties. An

interlaboratory comparison of a mixture of two

polystyrenes, one terminated with a proton, and

the other terminated with a hydroxyl group, was

performed using matrix-assisted laser desorptionionization mass spectrometry (MALDI-MS).

This interlaboratory comparison will be used

to quantify the accuracy and repeatability of

MALDI-MS in the identification of multiple

end groups as a result of polymer synthesis.

Charles M. Guttman and William E. Wallace

AMALDI-MS interlaboratory comparison of

 mixtures of synthetic polymers of the same repeat

unit and with closely matching molecular masses but

with different end groups was sponsored by NIST.

This interlaboratory comparison was designed to

determine how well a group of laboratories engaged in

MALDI-MS analyses of synthetic polymers agree on

the percent composition of each polymer in the mixture.

In an earlier interlaboratory comparison, NIST studied

the molecular mass distribution (MMD) and the moments

obtained by MALDI on polystyrene (PS) and compared

the results with those obtained by classical methods.

Interlaboratory comparisons enable us to gauge the needs

of the community for standard methods and materials,

to begin a dialog with the community on these needs,

and to steer our own research. The interlaboratory

comparison on mixtures of two polystyrenes with

different end groups is of particular interest to industry

where understanding and controlling the chemistry

of reactive pre-polymers is a major concern.

Figure 1: MALDI mass spectrum of polystyrene mixture.
15

Technical Highlights

over 40 u. Figure 2 shows that calibration was again

an important issue in this interlaboratory comparison.

The instrument calibration varied by as much as 20 u,

even though the end groups were known.

The agreement and standard deviation of data are

shown in Table 1. The fraction of PSOH polymer in

each mixture is given in the 2nd column. This column

assumes the PSOH-material is 7 % PSH polymer and

93 % PSOH polymer. Seven percent is the midpoint

of the range assigned by the NMR. It is seen from both

Figure 3 and Table 1 that the agreement between the

MALDI-MS and the gravimetric results for the fraction

of PSOH polymer in each mixture is good when judged

by the standard deviation of the MALDI results.

Figure 2: The average molecular mass of PSH end groups for

each laboratory. The red line represents the actual molecular

mass of the end groups.

Figure 3: The fraction of PSOH determined by MALDI compared

with the gravimetric data.

Table 1: The fraction of PSOH polymer by mass

and determined by MALDI

was seen in the higher variation in the fraction of PSOH

determined for Mix A and Mix E, where a minor component

may be lost in the noise. The result, which indicates

significant variation in the fraction of PSOH for instrument

mode, may be due to the resolution difference between

reflectron and linear mode. In order to better understand

the optimization of the MALDI-MS, we have begun

to study the influences of the instrument and sample

preparation parameters on the MALDI-MS signal.

We are using an orthogonal fractional factorial design

to study detector voltage, laser energy, delay time,

and ion optic voltages, as well as matrix and polymer

concentration. Once the effects of all parameters are

understood, optimization will be easier to obtain.

These results also recapitulate the need for an unbiased,

automated peak integration routine when the S/N is poor.

We will continue to refine our MassSpectator software as

a benchmark method to perform unbiased peak integration.

For More Information on this Topic

S.J. Wetzel, K.M. Flynn, B.M. Fanconi,

D.L. VanderHart (Polymers Division, NIST);

S. Leigh (Statistical Engineering Division, NIST)

C.M. Guttman, S.J. Wetzel, K.M. Flynn,

B.J. Fanconi, W.E. Wallace, and D.L. VanderHart,

“International Interlaboratory Comparison of Mixtures

of Polystyrenes with Different End Groups,”

Proceedings of the 52nd ASMS Conference on

Mass Spectrometry and Allied Topics, Nashville, TN.

C.M. Guttman, S.J. Wetzel, W.R. Blair,

B.M. Fanconi, J.E. Girard, R.J. Goldschmidt,

W.E. Wallace, and D.L. Vanderhart, Analytical

Chemistry 73(6), 1252–1262 (2001).

S.J. Wetzel, C.M. Guttman, and K.M. Flynn, “The

Influence of Matrix and Laser Power on the Molecular

Mass Distribution of Synthetic Polymers obtained by

MALDI,” Int. J. Mass Spectrometry, in press.

By MALDI MALDI

Mass Average Std Dev

Mix A 0.93 0.933 0.051

Mix B 0.716 0.746 0.086

Mix C 0.481 0.47 0.041

Mix D 0.284 0.259 0.051

Mix E 0.086 0.117 0.2

The key to “getting it right” in MALDI-MS, especially

for Mix A and Mix E, is to optimize the instrument. This

Figure 3 shows a plot of the “Theoretical Mixture

of PSOH” polymer fraction assuming 7 % PSH polymer

in the PSOH material from the NMR data. The plot

is compared to MALDI-MS data from some of the

participating laboratories. The agreement is generally

good, but the data show a wide range of variability

among the laboratories. Deviation of the data from the

expected percentages was found widest at the extremes

of concentration of 95:5 and 10:90 PSOH: PSH, but

even at the 50:50 ratio the deviation was as high as 10 %.

Mixtures of PS with Different End Groups
16

Technical Highlights

Extraordinary Transport Properties of Nanotube/Polymer

Nanocomposites

Figure 1: Optical microscopy image of 1 % by volume MWNT/PP

nanocomposite (obtained using a 100x objective) demonstrates

good dispersion of the MWNT and reveals a polydispersity in

nanotube length and shape. The MWNT volume fraction in this

figure equals φ = 0.01, which is close to the geometrical percolation

concentration where the CNT network first forms and where the

conductivity and stiffness of the nanocomposite increases by

orders of magnitude (see Figure 2).

polymer matrix creates additional contributions to

nanocomposite viscoelasticity that can have a radical

effect on the processing characteristics of these materials.

In Figure 2, we characterize the large changes

in viscoelasticity and conductivity for which

polymer composites containing CNT are well known.

Simultaneous measurements of σ and the shear moduli

(G ́, G ́ ́) characterize the elastic and viscous properties

of our composites. G ́ can be thought of as a measure

of “stiffness” and G ́ ́ provides a measurement of

viscous resistance to deformation. The ratio (G ́/G ́ ́)

or “loss tangent” (tan δ), is a measure of the composite

“firmness,” and we compare this basic quantity to σ.

We observe that both (G ́/G ́ ́) and σ increase with

φ and that this variation becomes rapid for MWNT

volume fraction φ in the range from 0.0025 to 0.01.

We see that adding MWNT to the PP matrix increases

the conductivity by an impressive seven orders of

magnitude as a percolating network structure forms.

G ́ and G ́ ́ become frequency independent as φ is

varied through the “gelation concentration,” φc ≈ 0.01.

In order to manufacture MWNT nanocomposites

into usable shapes, we must understand how the

network structure acts to influence their processing

behavior. The linear rheological and electrical transport

properties (Figure 2) are strongly altered by flow, as

There has been intense interest in composites of

polymers and carbon nanotubes (CNT) because

of the large transport property (conductivity,

elasticity, viscosity, thermal conductivity) changes

exhibited by these additives for relative low

CNT concentrations (≈ 1 % volume fraction).

NIST’s experience in the area of dielectric and

rheological measurement, in conjunction with

expertise in modeling, puts it in a unique position

to lead the development of new processing

concepts required by industry to utilize this

important new class of materials.

Kalman B. Migler and Jack F. Douglas

The combination of extended shape, rigidity and

deformability allows carbon nanotubes (CNT) to

be mechanically dispersed in polymer matrices in the

form of disordered network structures exhibiting a

gel-like rheology. Our measurements on representative

network-forming multi-wall carbon nanotube (MWNT)

dispersions in polypropylene (PP) indicate that these

materials exhibit extraordinary flow-induced property

changes. Specifically, electrical conductivity σ and

steady shear viscosity η both decrease strongly with

increasing shear rate γ& , and these nanocomposites

exhibit impressively large and negative normal stress

differences, a rarely reported phenomenon in

soft condensed matter. We illustrate the practical

implications of these non-linear transport properties

by showing that MWNTs eliminate die swell in our

nanocomposites, an effect crucial for their processing.

The strong interest in CNT “nanocomposites”

stems from their ability to affect thermal, electrical and

rheological properties for relatively small concentrations

of this type of additive. These additives have found

manufacturing applications in electrostatic painting,

protective coatings for electronic components, and

flammability reduction. Utilization of CNT for

more complex applications, however, requires an

understanding of how processing conditions (mixing,

molding, extrusion) influence nanocomposite properties.

Despite the high elastic modulus of CNT, their small

cross-sectional dimensions and large aspect ratio allows

them to bend substantially in response to inter-tube

interactions under processing conditions. This bending

leads to the formation of a disordered “web-like” structure

(see Figure 1) of substantial mechanical integrity. The

presence of a nanotube network interpenetrating the
17

Technical Highlights

Figure 3 indicates. Notably, both the conductivity

and the viscosity η(γ& ) exhibit a strong thinning.

The viscosity decreases over the full range of shear

explored here, whereas the conductivity shows a

plateau region at low shear. Moreover, a positive

normal force ∆N is observed in our nanocomposite for

φ < φc , where the matrix dominates the rheological

response (Figure 3), but ∆N becomes large and

negative for φ ≥ φc, compensating the large ∆N

exhibited by the matrix polymer. (A negative ∆N in

nanotube dispersions was reported by Lin–Gibson,

et al.) This has significant processing consequences.

Figure 2: Characterization of conductivity and viscolelasticity

of MWNT/PP nanocomposites (φ = 0.025; T = 200 °C).

Inset: Shear modulus as a function of frequency for a range

of nanotube concentrations.

Figure 3: Normal stress measurements showing slightly positive

normal stress for pure PP and increasingly negative normal

stress as the MWNT fraction increases. Inset: Conductivity and

viscosity as a function of shear rate for (φ = 0.025; T = 200 °C).

Figure 4: Comparison of PP extrudate with (A) and without (B)

added nanotubes. The red dashed lines correspond to the die size.

Since the extrusion of the nanocomposite is a basic

processing operation for which normal forces are

known to be important, we extruded a nanocomposite

sample (φ = 0.025) and found that the cross-section

actually shrinks upon extrusion (Figure 4). This

striking effect is contrasted with the extrusion of pure

PP where a nearly 6-fold increase in cross-sectional

area is observed. Evidently, the CNT change the

qualitative nature of the polymer flow.

The suppression of die swell of extruded polymers

by adding a relatively small amount of MWNT (φ ≈ 0.01)

offers a powerful tool for controlling dimensional

characteristics and surface distortion in manufacturing

composites. Our observations of strongly non-linear

rheology under flow (shear thinning and large, negative

normal stresses) imply that these fluids should exhibit

other “anomalous” flow characteristics (e.g., droplet

distortion and thread break-up) that are quite unlike

Newtonian fluids. Understanding these flow

characteristics is crucial for their processing.

For More Information on this Topic

S. Kharchenko, J. Obrzut, E. Hobbie (Polymers

Division, NIST)

S. Lin–Gibson, J.A. Pathak, E.A. Grulke, H. Wang,

and E.K. Hobbie, “Elastic Flow Instability in Nanotube

Suspensions,” Physical Review Letters 92, 048302-(1-4)

(2004).

S.B. Kharchenko, J.F. Douglas, J. Obrzut,

E.A. Grulke, and K.B. Migler, “Extraordinary Flow

Characteristics of Nanotube-Filled Polymer Materials,”

Nature Materials, in press.
18
19

The competitiveness of U.S. manufacturers

depends on their ability to create new product concepts

and to speed the translation from concept to market

while decreasing product cost. This is equally true

for well-established “commodity” industries, such

as automotive and aerospace, and rapidly growing

or emerging industries, such as biotechnology and

nanotechnology. For existing products, manufacturing

is a critical step in reducing product cycle time. Rapid,

low-cost development of manufacturing processes is

needed to incorporate new materials into complex

product shapes with higher performance at equivalent

or lower cost as the competing, established materials

and methods. For innovative product concepts, new

materials with increasing functionality are needed to

translate these concepts to reality.

To realize such improvements in materials and

manufacturing, MSEL is developing robust measurement

methods, models, standards, and materials and process

data needed for design, monitoring, and control of

manufacturing processes. A growing challenge is being

able to design, monitor, and control such materials and

manufacturing processes at size scales from nanometers

to meters. The Advanced Manufacturing Processes

Program focuses on the following high-impact areas:

■ Combinatorial, high-throughput methods for materials

ranging from thin films and nanocomposites to

micro- and macroscale material structures;

■ Industry-targeted R&D centered on unique

measurement facilities in forming of lightweight

metals for automotive applications, polymer

processing, and high-speed machining;

■ Innovative testbeds for emerging materials,

including carbon nanotubes and fuel cells;

■ National traceable standards having a major impact

on trade, such as hardness standards for metals

and process standards for polymers; and

■ Innovative, physics-based process modeling tools.

Our research is often conducted in close

collaboration with industrial consortia and standards

organizations. These collaborations not only ensure

the relevance of our research, but also promote rapid

transfer of our research to industry for implementation.

Three projects focused on Advanced Manufacturing

Processes are highlighted below.

NIST Combinatorial Methods Center (NCMC)

The NCMC develops novel high-throughput

measurement techniques and combinatorial experimental

strategies specifically geared towards materials research.

Program Overview

Advanced Manufacturing Processes

These tools enable rapid acquisition and analysis of

physical and chemical data, thereby accelerating the

pace of materials discovery and knowledge generation.

By providing measurement infrastructure, standards, and

protocols, and expanding existing capabilities relevant

to combinatorial approaches, the NCMC lowers barriers

to the widespread industrial implementation of this new

R&D paradigm. MSEL uses a two-pronged strategy for

accelerating the development and implementation of these

approaches: an active intramural R&D program that

demonstrates the ability of combinatorial methods to

produce cutting-edge scientific research and an ambitious

outreach activity; key to this effort is the validation of

these approaches with respect to traditional “one at a time”

experimental strategies.

Forming of Lightweight Metals

Automobile manufacturing is a materials intensive

industry that involves about 10 % of the U.S. workforce.

In spite of the use of the most advanced, cost-effective

technologies, this globally competitive industry has major

productivity issues related to measurement science and

data. Chief among these is the difficulty of designing

stamping dies for sheet metal forming. An ATP-sponsored

workshop (“The Road Ahead,” June 20–22, 2000) identified

production of working die sets as the main obstacle to

reducing the time between accepting a new design and

actual production of parts. This is also the largest single

cost (besides labor) in car production. To benefit from

weight savings enabled by new high-strength steels

and aluminum alloys, a whole new level of formability

measurement methods, models, and data is needed,

together with a better understanding of the physics

behind metal deformation. MSEL is working with

U.S. automakers and their suppliers to fill this need.

Polymer Processing

Polymers have become ubiquitous in the modern

economy because of their processability, high functionality,

and low cost. However, these materials can exhibit

complex and sometimes catastrophic responses to the

forces imposed during manufacturing, thereby limiting

processing rates and the ability to predict ultimate

properties. The focus of our polymer research is on

microfluidics and microscale processing, modeling of

processing instabilities, and on-line process monitoring

of polymers. Our unique extrusion visualization facility

combines in-line microscopy and light scattering for the

study of polymer blends, extrusion instabilities, and the

action of additives. These measurements are carried out

in close collaboration with interested industrial partners.

Contact: Carol A. Handwerker or

Kalman Migler (Polymers Division)
20

Advanced Manufacturing Processes

NIST Combinatorial Methods Center (NCMC)

Pioneer and Partner in Accelerated Materials Research

Combinatorial and high-throughput (C&HT)

techniques hold great potential for making

materials research more productive, more

thorough, and less wasteful. However, significant

barriers prevent the widespread adoption of

these revolutionary methods. Through creative,

cost-effective measurement solutions, and with

an eye towards fruitful collaboration, the NIST

Combinatorial Methods Center (NCMC) strives

to ease the acquisition of C&HT techniques by

the materials research community.

Cher H. Davis and Michael J. Fasolka

Now in its third year, the NIST Combinatorial Methods

Center continues to be a sought after partner among

industry, government laboratories, and academics

interested in acquiring C&HT research capabilities for

materials research. Indeed, the NCMC consortium

currently includes 22 member institutions (see table)

representing a broad cross-section of the materials

research sector.

The NCMC is successful because it serves the

combinatorial materials research community on several

levels. Our foundation is the extensive suite of NCMC

technologies, which provide measurement solutions to

parties interested in acquiring C&HT capabilities. Many

of these methods are described elsewhere in this report,

as identified by the NCMC symbol (see top right corner).

Technology transfer efforts complement our methods

foundation, as evidenced by the many institutions that

have adopted NCMC techniques. For example, Air

Products, Rhodia, National Starch (ICI), Dow, Procter

and Gamble, and Eastman, plus many universities, have

replicated NCMC devices in their laboratories. In this

respect, NCMC Focused Projects are a new paradigm for

NIST/industry partnership, which are extremely effective

for both methods development and technology transfer.

with Procter and Gamble and National Starch (ICI) to

produce HT microfluidic measurements of interfacial

tension. The second Focused Project, sponsored by Intel

and National Starch (ICI), will produce C&HT methods

that gauge the performance of epoxy adhesives for flip

chip electronics applications. Several other Focused

Projects are in development.

New scientific endeavors (such as C&HT materials

research) gain momentum when stake-holding parties are

brought together. Accordingly, to advance the field, the

NCMC invests itself in community forming activities aimed

at information transfer and goal consolidation among

institutions interested in C&HT research. Industry

workshops play a major role in this endeavor, and in

FY04 we hosted the 4th and 5th additions to the NCMC

workshop series, focused on Polymer Formulations

and Processing and Characterization, respectively.

Under a Focused Project, NIST scientists and 2–3 member

companies collaborate to develop a particular C&HT

measurement solution. While the research is co-funded

by industry members, we avoid the study of proprietary

materials and all results are published; this allows the

research to have the broadest impact. Currently, there

are two Focused Projects. In the first, NIST is working

“The focused project approach is particularly effective since it

allows active collaboration with industry, allowing real needs

to be addressed, and resulting technology transferred. The

[NCMC] is at the leading edge of combi-based material science

discovery, and this reflects both the quality of the research program

and of the people.” — Dr. J. Carroll, ICI/National Starch,

Strategic Technology Group

“The NCMC provides a unique platform to exchange information and ideas with other member companies who form a part of

this consortium.”— D. Bhattacharya, Global Coatings Application

Development, Eastman Chemical Co.

Moreover, we have been very active in organizing

symposia at national conferences. In FY04 alone,

NCMC staff developed and organized multi-day

symposia on C&HT methods for the Materials Research

Society, the American Chemical Society, the Adhesion

Society, and the Knowledge Foundation.

For more information on the NCMC, C&HT

technologies, or post-doctoral research opportunities,

see our website at http://www.nist.gov/combi.

“I have heard nothing but praise from all who attended the

recent NCMC conference. . .NIST did a superb job organizing

the symposia, selecting thought-provoking topics, and leading

good general discussions.” — Personal observation of J. Dias,

ExxonMobil; Chair ACS PMSE

Contributors and Collaborators

K.L. Beers, C.M. Stafford, A. Karim, E.J. Amis,

The Multivariant Measurement Methods Group

(Polymers Division, NIST)

NCMC Members (*New in FY2004):

3M Honeywell International

Accelrys* Hysitron International*

Air Force Research Lab Intel*

Air Products & Chemicals ICI/National Starch & Chemicals

Akzo Nobel Michelin

Atofina Chemicals* PPG Industries

BP* Procter & Gamble

BASF Rhodia

Bayer Polymers Sealed Air Corp*

Dow Chemical Company Symyx*

Eastman Chemical* Univ. of Southern Mississippi

ExxonMobil Research Veeco/Digital Instruments*
21

Advanced Manufacturing Processes

Industrial development of complex mixtures of

materials known as “formulations” has traditionally

relied upon empirical data and technical intuition,

resulting from years of trial and error studies.

We accelerate product discovery and optimization

by providing new testing platforms that use

high-throughput and combinatorial methods to

rationally explore formulations variable space.

These techniques, which have proven powerfully

effective in drug and catalyst discovery, are now

adapted to the myriad of materials measurements

to which complex mixtures are typically submitted.

Kathryn L. Beers and João T. Cabral

Commercially available combinatorial and highthroughput (C&HT) fluid handling and measurement

capabilities have enabled tremendous progress in industrial

product development; however, the platforms are often

costly and time-consuming to implement. The approach

adopted by most manufacturers has been to build these

automated platforms that mimic the development process

for a specific material in a narrow application. This greatly

increases data acquisition rates, but it is challenging to

adapt this system-specific infrastructure to changing R&D

needs. In response, our research aims to develop new

methods for the manipulation and measurement of

complex polymeric fluids, thereby providing flexible and

inexpensive alternatives to robotics-driven instrumentation.

To improve the versatility of high-throughput

formulations testing, we employ microfluidic technology

to build a toolset of complementary library fabrication

and test methods. The preparation of devices is fast

and modular, allowing for rapid prototype development

Polymer Formulations: Rapid Prototyping Technology

for Polymeric Materials Development

Figure 1: Profilometry image of a fluidics device master

prepared by patterning an optical resin. 3-D channel structure is

possible due to the frontal polymerization mechanism of the resin.

Figure 2: High-throughput cloud point curves (graph)

determined from uniform temperature sweeps of an array of

blend compositions in a prototyped sample plate (top images).

Complex fluid capabilities developed this year to

complement our library fabrication include a high

throughput microfluidic device for measuring interfacial

tension (see related article in this report), a combinatorial

magneto-driven rheometer, and a small angle light

scattering (SALS) instrument for high throughput

screening of polymer blends and solutions. The SALS

instrument builds upon our work demonstrating high

throughput cloud point mapping of polymer blends using

sample libraries prepared in prototyped arrays (Figure 2).

Contributors and Collaborators

J.T. Cabral, Z.T. Cygan, A.I. Norman, H.J. Walls,

T. Wu, C. Xu, Y. Mei, S.D. Hudson, J.F. Douglas,

M.J. Fasolka, A. Karim, E.J. Amis (Polymers Division,

NIST); J.D. Batteas (Surface and Microanalysis

Division, CSTL)

and increased flexibility. Our fabrication method is an

adaptation of existing procedures that uses an optical

resin with good solvent resistance and obeys a frontal

polymerization mechanism, which enables us to prepare

quasi-three-dimensional channel structures (Figure 1).

This year, we have built and demonstrated several

methods of preparing polymer libraries in microfluidic

devices (see Technical Highlights: Polymer Library

Fabrication Techniques Using Microfluidic Technology).

The libraries produced are designed to feed directly into

the thin film gradient tools previously developed in the

NCMC as well as the fluid measurement capabilities

currently being built in our lab.
22

Advanced Manufacturing Processes

We are developing new metrologies for quantifying

the dispersion and orientation of carbon nanotubes

in polymer melts and solutions. This will open

the door to innovative processes and in-line

characterization methods that will, in turn,

empower novel approaches in materials science

and engineering, creating a pathway toward the

realization of a modern generation of materials

and applications for carbon nanotubes.

Erik K. Hobbie and Barry J. Bauer

Carbon nanotubes exhibit remarkable physical

properties, and there is considerable interest in using

them as nanoscale building blocks for a new generation

of novel materials. Despite this promise, fundamental

issues related to the dispersion, fractionation, and

orientation of individual carbon nanotubes remain

unresolved, and bulk processing schemes do not yet

exist. In fact, techniques for measuring these parameters

in nanotubes are primitive. In light of these issues, we

have established a program to enable proficient nanotube

processing by quantifying the response of carbon nanotube

suspensions and melts to changes in such parameters as

composition, aspect ratio, shear stress, and dispersant.

The manufacture of nanotube-based devices and

composites typically entails suspending them in an

aqueous or molten polymeric media and subjecting them

to shearing stresses. We have completed a comprehensive

set of measurements detailing the response of nanotube

suspensions to imposed flows. These experiments

have been conducted over a wide range of shear rates,

concentrations, and tube type (single or multi-wall).

By combining optical methodologies with neutron

scattering, the influence of flow on nanotube clustering,

orientation, and dispersion has been elucidated.

Typical optical measurements are shown in Figure 1a,

which shows scaled birefringence as a function of a

scaled shear rate (Peclet number), where the left inset

(red scale bar) is a SEM image of the multi-wall

nanotubes (MWNT), and the right inset (blue scale bar)

is an AFM image of a single-wall nanotube (SWNT)

bundle (scale bar = 50 nm). The measured order

parameter has been scaled onto the data, and the line

is a power-law fit. Figure 1b shows an analogous plot

of the birefringence, where the left inset is an optical

micrograph of a MWNT (scale bar = 5 μm), and the

right inset is a SANS pattern for a SWNT suspension

(scale bar = 0.06 nm–1). The scaling shown in Figure 1

confirms theoretical predictions of the importance of

hydrodynamic interactions in the semi-dilute regime.

One intriguing result is a segregation by tube length in

Carbon Nanotube Processing

the shear cell; this suggests a path towards the goal

of the production of monodisperse nanotubes.

A “grand challenge” in nanotube research is to break

up the clusters and “ropes” that naturally form so that

isolated single-wall tubes are realized, which can be

utilized in applications. Numerous recipes for dispersing

the nanotubes have been proposed, but there is little

quantification of the resulting suspensions and no

powerful method for comparing different techniques.

We are employing neutron scattering to establish

base-line standards for nanotube dispersion and

orientation using a variety of functionalization and

dispersion methods. These measurements will resolve

a number of controversial and outstanding questions

regarding form and structure in single-walled carbon

nanotube suspensions, including persistence length

and phase behavior.

Contributors and Collaborators

D. Fry (Polymers Division, NIST); H. Wang

(Michigan Tech)

Figure 1: Scaled birefringence (∆n ́) and dichroism (∆n ́ ́) as

a function of Peclet number for a variety of carbon nanotube

suspensions. (φ is the volume fraction.)
23

Advanced Manufacturing Processes

As polymer processing is carried out under highly

non-equilibrium conditions, it is difficult to assess

the state of the polymer without in-situ real-time

measurements. Our program develops and applies

in-situ measurement technology to problems chosen

on the basis of input from our industrial partners.

This year’s focus has been on the state of dispersion

of nanoclay-polymer composites, as well as on

additives to control the extrusion process.

Anthony Bur and Kalman Migler

I

n the marketplace of commodity polymers, much

of the value added is due to processing operations.

Indeed, the ability to precisely control product quality

often determines the economic viability of a product.

Due to the highly non-linear and non-equilibrium

processes that occur during large-scale processing

operations, it is generally not feasible to obtain accurate

determinations of the relevant process state that would

allow precision control. Thus, most of the quality

control is engineered into the manufacturing process

during the R&D stage.

Our program has built numerous collaborative

relationships with the upstream industries, such as

materials producers, additive suppliers, and instrument

manufacturers to further industry’s ability to monitor

processing parameters. We have developed a variety

of on-line instruments which can characterize critical

parameters of the polymer during processing such as

its temperature, velocity field, molecular orientation

and morphology of dispersed components. This year

we focused on two projects: the behavior of polymer

additives during processing; and techniques to assess the

state of dispersion of clay in polymer nanocomposites.

Additives are frequently mixed into polymeric

materials in minute quantities in order to make them

processable into the typical products well known to

consumers, such as plastic sheets, pipes, and wire

insulation. However, the basis for the effectiveness

of these additives remained unknown because the

existing tools available to measure their behavior in the

manufacturing process were rather crude. We utilized

the optical phenomena of Frustrated Total Internal

Reflection (Frus-TIR) to directly visualize the behavior

of fluoropolymer additives in polyethylene melts.

From visualization of the additive coating process,

we developed a semi-quantitative model which predicts

the coating efficiency as a function of additive droplet

size and shear rate. A collaboration between NIST,

DuPont Dow Elastomers, The University of Minnesota,

Processing Flows and Instabilities

and The University of Maryland is now using this

Frus-TIR technique to test for the critical factors

that influence the coating efficiency.

Figure 1: Use of dielectric spectroscopy to assess the state of

dispersion of a nanoclay composite. Nylon 11 compounded with

four different clays.

The second focus was to measure the dispersion

of nanoclay additives using an on-line dielectric cell.

This cell is effectively a slit die with interdigitated

electrodes glazed onto one wall. Past work has shown

that it can also be used to carry out rheological and

optical measurements. The program achieved its goal

of finding the signature of exfoliation in the spectra of

the dielectric measurements (see Figure 1). Further,

the state of exfoliation was measured from two

complementary methods: the changes in the optical

fluorescence when certain dyes were incorporated

into the clay; and changes in the transparency of the

material as a function of exfoliation. This last method

is particularly inexpensive and may be of use to

end-users. These measurements correlated well

with the traditional laborious off-line techniques

(transmission electron microscopy and x-ray).

Contributors and Collaborators

S. Kharchenko, Y.H. Lee, S. Roth (Polymers Division;

NIST); M. McBrearty (Chemical Electrophysics);

D. Bigio, M. Meillon, D. Morgan (U. Maryland); S. Oriani

(DuPont Dow Elastomers); C. Macosko (U. Minnesota);

J. Gilman (BFRL, NIST); P. Maupin (DOE)
24

Traditional measures of molecular mass (and

the standards derived from them) provide either

absolute values for only one moment of the

distribution or relative values for the entire

distribution. As we discovered from our two

recent industry workshops, producers and users

of synthetic polymers, analytical laboratories,

and standards developing organizations, need

a method (and standards derived from it)

for absolute molecular mass distribution

determination. Mass spectrometry is being

developed as such a method. Both Type A

(“random”) and Type B (“systematic”)

uncertainties must be included in determining

the uncertainty budget for mass spectrometry.

William E. Wallace

I

n mass spectrometry, methods exist to calibrate

the mass axis with high precision and accuracy.

In contrast, the ion-intensity axis is extremely difficult

to calibrate. This leads to large uncertainties in

quantifying the content of mixtures. This is true

whether the mixture is composed of different

oligomeric species of the same polymer (i.e., the

molecular mass distribution), of polymers with the

same repeat unit but having different end groups

(e.g., pre-polymers), or polymers having different

repeat units (i.e., copolymers). The aim of this project

is to calibrate the ion intensity axis. This task has

been divided into three parts: sample preparation /ion

production, instrument optimization, and data analysis.

Matrix-assisted laser desorption/ionization

(MALDI) is used to create intact gaseous

macromolecular ions. We have begun to study the

MALDI ion-creation process using two-dimensional

combinatorial libraries where the analyte:matrix ratio

is varied in one dimension and the analyte:salt ratio

is varied in the other. We add a factorial design

methodology to optimize the instrument parameters

at each composition using the signal-to-noise ratio.

Instrument parameters to be optimized included

laser energy, several critical ion optics voltages,

detector voltage, as well as analyte:matrix ratio and

matrix material. From this, it was discovered that

the detector voltage was the single most important

factor, followed by the laser energy. Additionally,

we continue to develop the MassSpectator computer

code to perform unbiased processing of the data.

To gain greater insight into the complex mechanisms

of ion creation, the MALDI process was studied as a

Quantitative Polymer Mass Spectrometry

function of sample temperature. The common MALDI

matrix 2,5-dihydroxybenzoic acid (2,5-DHB) was used

due to the extensive literature on its physical properties.

Due to the high vapor pressure of 2,5-DHB, single

crystals were necessary to minimize the surface-tovolume ratio and thereby decrease the sublimation rate.

Advanced Manufacturing Processes

Figure 1: A 2,5 DHB single crystal on the sample stage.

The bright yellow feature is the near UV laser spot. Notice the

light pipe effect as visible radiation escapes from the ends of

the sample. The sample is approximately 3 mm long.

It was observed that a steep rise in ion production

occurs at 90 oC, achieved a maximum between 120 oC

to 130 oC, then decreased sharply to a minimum at 130 oC

to 140 oC, and returned to a second maximum value at

150 oC. Above 150 oC, useful information could not be

obtained because of rapid volatilization of the sample

into the vacuum. The overall trend in ion production is

well described by a recent two-step theory of the laser

desorption/ionization process, which takes into account

the temperature-dependent effects of plume expansion.

It was observed that thermal dehydration, condensation,

and decarboxylation reactions increase the volume of

gas released under laser ablation at high temperatures.

The resultant higher local pressure at the crystal surface

was found to have a profound effect on gas-phase ion

formation with higher pressures leading to lower ion

production.

Contributors and Collaborators

M.A. Arnould, B.J. Bauer, W.R. Blair, H.C.M. Byrd,

B.M. Fanconi, K.M. Flynn, C.M. Guttman, D.L. VanderHart,

S.J. Wetzel (Polymers Division, NIST); A.J. Kearsley,

P.M. Ketcham (Mathematical and Computational Sciences

Division, NIST); J.J. Filliben, J. Lu (Statistical Engineering

Division, NIST); S.A. Audino, J.E. Girard, Z. Vakili

(American University); R. Knochenmuss (Novartis);

N. Sari (CARB); Y. Brun (DuPont)
25

Advanced Manufacturing Processes

Polymer Standards

Producers, processors, and users of synthetic

polymers use polymer standards for calibration of

instruments, assessment of laboratory proficiency,

test method development, and materials improvement.

NIST assists in the standards process by providing

standard reference materials (SRM®), reference

materials (RM), and reference data. Activities

include recertifying SRM®s and RMs as stock is

depleted, determining opportunities for production

of new SRM®s and RMs, producing new SRM®s

and RMs and building databases of relevant data

pertaining to SRM®s and RMs.

Bruno Fanconi, Charles Guttman, and John Tesk

Recertification of SRM® 1476

SRM® 1476, a branched polyethylene, was originally

issued as a melt flow rate standard. It was discontinued

because insufficient material remained for recertification

as a melt flow rate standard. During its availability,

SRM® 1476 was also used in studies of branching in

polyethylene, a desirable molecular characteristic for

certain types of products. Although chemists now have

methods to produce a variety of branch structures,

measurement methods to quantify the critical aspects

of the branch architecture are lacking. Owing to the

available molecular data on SRM® 1476, manufacturers

of chromatographs include small quantities of the

original SRM® 1476 with purchases of their instruments

for comparative measurements. NIST has received

inquiries from manufacturers, researchers and resin

producers about making the remaining supply of SRM®

1476 resin available, not as a melt flow rate standard,

but as an aid in chromatographic measurements. The

remaining supply of SRM® 1476 resin was sufficient

for this purpose. Hence, recertification of SRM® 1476

resin for chromatographic measurements was completed

in FY 2004. Although the new SRM is not intended as

a melt flow rate standard, it remains certified for this

purpose to assure continuity with the original material.

Reference Scaffolds for Tissue Engineering

At the November 19, 2003 meeting of ASTM

International Committee F04.42 — Tissue Engineered

Biomaterials, a task force was initiated for the development

of reference scaffolds for tissue-engineered medical

products (TEMPs). Reference scaffolds had been

identified at a NIST workshop as the most needed

reference material for TEMPs. The task force will conduct

measurements to characterize test scaffolds that will

be supplied to its members; the results will be used to

determine the most useful characterizations to employ when

the reference scaffolds are produced. Scaffolds of known

porosity, interconnectivity, surface and bulk chemistry,

physical and mechanical properties, and cellular reactivity

are needed. Initially, the focus will be on characterizing

porosity (pore volume and pore size distribution),

connectivity, and interconnectivity of pores and work

toward consistent, unambiguous understanding of

terminology. Scaffolds that consist of a regular array of

cubic pores, such as with 600 μm pore-edge dimensions

and consistent interconnections, were identified for

the task force’s initial study. Micro-x-ray Computed

Tomography (μ-CT) was used for preliminary evaluation

of scaffold designs manufactured by different processes,

materials, dimensions, and pore size. On this basis, two

designs were chosen for distribution to the 17 laboratories

participating in the ASTM activity. Laboratory evaluations

of these designs will ensure that the characteristics needed

for the reference scaffolds will be well defined and that

their measurements will produce consistent results when

the reference scaffolds are produced. The reference

scaffolds will be available for distribution to researchers

and developers of scaffolds for tissue engineering

applications. Initial measurements by NIST showed that

μ-CT would be an important measurement method for

distinguishing scaffolds with acceptably consistent features.

Figure 1: Cubic scaffold with cubic pores (left) and μ-CT

scaffold slice (right).

Figure 2: Porosity as a function of depth of μ-CT slice (layer).

Contributors and Collaborators

J. Dunkers, F. Wang, M. Chiang, M. Cicerone,

K. Flynn, W. Blair, J. Maurey, S. Wetzel (Polymers

Division, NIST); M. Yaszemski, E. Jabbari, L. Lu

(Mayo Clinic); D. Dean, M. Cooke (Case Western

Reserve University)
26
27

Program Overview

New materials and devices are radically changing

the treatment of injury and disease, yet it is clear that

within this rapidly evolving segment of the materials

industry, a basic measurement infrastructure does

not exist. The Biomaterials Program develops

measurement methods, standards, and fundamental

scientific understanding at the interface between the

materials and biological sciences. For the health care

industry, we focus on dental and medical sectors that

apply synthetic materials for replacement, restoration,

and regeneration of damaged or diseased tissue.

Three primary foci exist within this program:

biocompatibility, biomaterials characterization, and

materials measurements applied to biological systems.

Whether the medical issue involves implanting

a hip- or knee-joint prosthesis, a synthetic bone graft,

or a tissue engineering scaffold into the human body,

one primary issue is biocompatibility. Using our

expertise in materials science, we have developed

suitable Reference Materials (RM) for investigating

biocompatibility and implant suitability. Research has

focused on measuring cellular response to powders

and bulk materials that are candidates for implants;

recently, we produced a realistic wear particle Standard

Reference Material (SRM® 2880) for bioactivity testing.

Work on quantitative methods of biomaterials

characterization includes assays for adhesion,

viability, proliferation, and differentiation of bone

cells, 3-dimensional structural/functional imaging

of tissue in-growth, and biochemical assays to

quantify inflammatory responses to synthetic materials.

The focus of this effort is bridging the gap between

fundamental knowledge and the product development

needs in industry. For example, in collaboration with

the Chemical Science and Technology Laboratory,

we are developing measurement methodologies and

reference materials to assess interactions in complex

systems of living cells with synthetic materials.

The expected outcome of this work includes reference

substrates that induce specific cellular responses,

and engineered DNA vectors to act as fluorescent

reporters of cellular responses.

Another example of our effort to bridge this gap

is our collaboration with the dental industry, which

is primarily composed of small manufacturers with

limited R&D capability. Collaborations with the

American Dental Association Foundation (ADAF)

develop improved materials and materials measurements

techniques, patent and license these inventions, and,

most importantly, provide a technical foundation.

Research focuses on improved understanding of the

synergistic interaction of the phases of polymer-based

composites and the mechanisms of adhesion to dentin

Biomaterials

and enamel. This approach will ultimately lead to

materials with improved durability, toughness, and

adhesion to contiguous tooth structure. We also

collaborate with the ADAF to develop metrology

for the biocompatibility of synthetic bone grafts.

In this era of interdisciplinary research,

we provide an added dimension. By taking a

physical/mechanical approach to how cells function,

respond, and remodel in interaction with synthetic

materials, we provide skill sets typically absent in the

biomedical community. Mechanical properties issues

also arise when considering synthetic bone grafts

and tissue engineering scaffolds. Complementing

traditional bulk mechanical property measurements,

combinatorial approaches are being developed to

identify compositions and surface features that

affect properties such as biocompatibility and

mechanical durability.

Our mechanical property metrology extends further

to biological systems that span the range from individual

neurons and muscle cells to complete pulmonary

arteries. This necessitates the development of unique

mechanical testing platforms and application of a

materials science approach to understanding integrated

properties. Recently, we have developed a bioreactor

capable of applying biaxial stresses and allowing

monitoring of the stress and strain of a two-dimensional

scaffold sheet during tissue growth.

Fundamental to the Biomaterials program is

recognition of the need for an integrated systems

approach. Collaborations among and between project

teams are critical to progress against the ambitious

goals of this program.

Contact: Eric J. Amis (Polymers Division)
28

Biomaterials

Polymeric dental materials are finding increasing

applications in dentistry and allied biomedical

fields. As part of a joint research effort

supported by the National Institute of Dental and

Craniofacial Research and also in collaboration

with the American Dental Association Health

Foundation Paffenbarger Research Center,

NIST is providing the dental industry with a

fundamental knowledge base that will aid in

the prediction of clinical performance of

dental materials.

Joseph M. Antonucci and Elizabeth Wilder

I

norganic fillers of various types, sizes and shapes

are commonly used to modify polymer properties.

In resin-based dental composites, fillers are added to

enhance the modulus, hardness and strength of the

polymer phase while also reducing its coefficient of

thermal expansion and volumetric contraction during

polymerization. In order to achieve composites with

optimal properties, it is also necessary to provide an

effective, high-quality interfacial phase that will make

the filler both interactive and reinforcing with respect

to the polymeric matrix phase.

Recent developments in nanotechnology have

spurred interest in nano-size fillers and additives for

dental materials. The interactions that occur between

the disparate polymer matrix and inorganic filler phases

are increasingly important to elucidate for nano-fillers

due to their high surface area. Surface treatments of

the nano-sized fillers, designed to generate desirable

interfacial phases upon polymerization, assume even

greater importance in nanocomposites compared to

conventionally sized materials.

In this project, we investigate two types of

nanofillers: (1) a pure silica particulate surface-treated

Structure-Property Relationships in Dental Nanocomposites

with blends of two silane agents, and (2) a wellcharacterized amorphous calcium phosphate (ACP)

particulate modified by exposure to the organogelator

dibenzylidene sorbitol (DBS). Before treatment, both

of these fillers exist as complex aggregates that are

difficult to incorporate into dental resins.

The objective of our research with the nano-sized

silica filler was to explore how the interfacial chemical

structural variations arising from using a blend of

two silane agents (Figure 1), one reactive (MPTMS)

with the resin and the second non-reactive (OTMS),

influence certain critical properties of the composites.

It was found that processability, as measured by the

facility of introducing the silica into the resins, was

improved if the silane system contained OTMS.

With equal parts by mass of MPTMS and OTMS, at

least the same degree of reinforcement, measured by

a biaxial flexure or 3-point flexural test, was achieved.

The dual silane treatment also allows for the formulation

of nanocomposites with higher filler contents.

 The second part of this project was aimed at

determining the effect of DBS networks on shrinkage,

stress development and mechanical properties of a

bioactive composite utilizing ACP as the filler phase.

DBS is capable of self-assembling into nano-scale

fibrillar networks in a variety of dental monomers.

The addition of DBS-reduced pore defects (Figure 2),

increased biaxial flexure strength and reduced

polymerization shrinkage and stress. These results

suggest that dual silanization techniques and the use

of organogelators may provide facile ways to enhance

critical properties of polymeric dental composites

and related materials.

Contributors and Collaborators

S. Lin–Gibson, N. Washburn, W. McDonough,

K. Wilson (Polymers Division, NIST); D. Skrtic

(American Dental Association Health Foundation,

Paffenbarger Research Center)

Figure 1: Structure of (top) octyltrimethoxysilane(OTMS)

and (bottom) methacryloxypropyltrimethoxysilane (MPTMS).

Figure 2: Fractured ACP composite with: a) 0 % and

b) 8 % mass fraction DBS.
29

Biomaterials

This project develops methods for determining

the viability of tissue engineered medical

products (TEMPs) through the use of in-vitro

imaging coupled with data reduction techniques.

These techniques are vital for distilling the

voluminous amount of imaging data down to

selected metrics of interest relating to TEMP

viability. We illustrate this approach by using

various imaging techniques, along with 3D image

quantitation, to establish relationships between

cell proliferation and scaffold microstructure.

Joy P. Dunkers and Forrest A. Landis

TEMP Imaging: Collinear Optical Coherence/

Confocal Fluorescence Microscopies

We use collinear optical coherence microscopy

(OCM) in conjunction with one photon confocal

fluorescence microscopy (CFM) as a multifunctional

technique for characterization of TEMPs. OCM with

its unparalleled combination of resolution (≈ 1 μm) and

sensitivity (> 100 dB) is well-suited for imaging TEMPs.

CFM has proven to be an extremely powerful technique

for understanding cell viability, differentiation, and

protein expression in tissue engineering and provides

complementary information to the structural

characterization provided by OCM.

Figure 1 shows OCM/CFM imaging data on a

polymer scaffold. The OCM channel images changes

in refractive index. In the image, the scaffold is shown

in red and pores in black. The scaffold was seeded

for 56 d with osteoblasts and subsequently the nuclei

were stained. The presence of cells was detected using

CFM (shown in yellow). From this image, it is clear

that the cells are highly confluent along the surface of

most of the scaffold including the pore walls but do

not yet completely fill the pores. The image size is

500 μm × 500 μm × 100 μm.

Multi-Modal Imaging and Quantitative Data Reduction

Methods for Regenerative Medicine

Data Reduction Method:

3D Image Quantitation

We have developed methods to compute critical

quantities from the imaging data, which can then be related

to cell response. We have implemented algorithms that

calculate pore volume, pore size distribution and structural

anisotropy from 3D imaging data. Quantities such as

pore connectivity and tortuosity are also expected to be

influential, and algorithms are currently being developed.

Data Reduction Method:

Immersive Visualization

Immersive visualization (IV) is a “virtual-reality”

experience that literally puts you in the middle of your

data. This is particularly advantageous when there

are multiple types of volumetric data to be displayed

simultaneously. IV allows one to see the entire data set

at once and manipulate it in real time, which facilitates

both qualitative and quantitative evaluation. Figure 2

shows a scientist exploring a TEMP imaging data set

with a tool (arrow) in an immersive environment.

Figure 1: OCM/CFM image of a polymer scaffold.

Figure 2: A scientist exploring a TEMP imaging data set in an

immersive environment.

Impact

Our collinear OCM/CFM work has been highlighted

by the biomedical community:

“Two Imaging Techniques Work Better Than One,”

Biophotonics International, January 2004.

“Microscopes Provide New View for Tissue

Engineering,” Medical News Today, December 10, 2003.

Contributors and Collaborators

J. Stephens, M. Chiang, X. Wang, M. Cicerone,

J. Cooper (Polymers Division, NIST); J. Devaney,

J. Hagedorn, S. Satterfield (Mathematical and

Computational Sciences Division, NIST)
30

Biomaterials

Design issues relating to bioactive devices for

regenerative medicine reflect the complexity

of biological and materials issues, and their

interactions. Regulatory issues also reflect this

complexity. Quantifiable, reliable metrics that

are relevant to success of tissue engineering (TE)

constructs in properly supporting cell and tissue

growth are needed to reduce the impact of this

complexity. We are helping to define and

develop these metrics.

Marcus T. Cicerone

The current efforts on this project are divided into

two main areas: porosity measurements and useful

definitions of porosity and chondrocyte response to

dynamic environments. We are preparing to embark

on another area — transferring results of cell-surface

compatibility studies in 2D to 3D scaffolds. In each

of these areas, we are emphasizing the use of unique

volumetric imaging capabilities in the Polymers

Division. We also apply real-time PCR (polymerase

chain reaction) and other more common methods,

such as histology.

Chondrocyte Response

Links have been established between a chondrocyte’s

dynamic environment and composition of the extracellular matrix (ECM) it produces. We are developing

measurement tools to help determine how the dynamics

of the environment is sensed by the cell, and stimulus

levels required for engineering cartilage with specific ECM

compositions. This work is in collaboration with top

researchers at the National Institutes of Health’s (NIH)

National Institute of Arthritis and Musculoskeletal and

Skin Diseases (NIAMS).

Our working hypothesis is that physical deformation

of chondrocytes influences ECM composition in the

cartilage produced by both an intracellular transduction

mechanism and increased perfusion of nutrients. This

has been tested by applying variable pulsitile fluid stresses

to chondrocytes encapsulated in poly(ethylene glycol)

dimethacrylate gels. Cellular responses and matrix

production are characterized by histological techniques,

optical coherence tomography (OCM), and real time PCR.

We are developing spectroscopic imaging methods that

will aid in non-invasive determination of ECM composition.

Output of this work will be presented at the

“Musculoskeletal Biology & Bioengineering Gordon

Research Conference” and the “Polymer Network

Conference” (both 2004). We also have a manuscript

in preparation for Journal of Orthopedic Research.

Tissue Engineering Scaffolds

Porosity

It is generally agreed that “porosity” of tissue

scaffolds is an important parameter; however, there is

a general lack of agreement as to precisely what aspect

of “porosity” is important, or how best to measure it.

We have initiated a collaborative project through

ASTM (Task Force F04.42.06) to identify aspects of

scaffold porosity that are most relevant and to come to

consensus on how these aspects should be quantified.

Seventeen laboratories throughout the world have joined

us in this activity, which will be carried out in several

stages, ultimately leading to the development of a

reference scaffold for porosity measurements.

Output of this work thus far has included an ASTM

draft guide for scaffold characterization (in preparation).

Also, this work has been reported at the “Society of

Biomaterials Meeting” and “World Biomaterials Meeting,”

both in 2004.

Contributors and Collaborators

L. Bailey, J. Cooper, B. Fanconi, C. Khatri,

S. Lin–Gibson, J. Tesk, F. Wang (Polymers Division,

NIST); B. Vogel (Iowa State University); R. Li,

R. Tuan (NIH/NIAMS)

Figure 1: Histology (panels a and b) showed an increase in ECM

(sulfated proteoglycan) production for the dynamically cultured

scaffolds as compared to the static culture scaffold. Real-Time

PCR (panel c) showed the expression of genes for collagen type II

and aggrecan under dynamic conditions and only aggrecan under

static conditions.
31

Biomaterials

Current methods for biomaterials development

involve one-specimen-at-a-time characterization

which is costly and time-consuming. In order to

accelerate development, we have created a suite

of high-throughput and combinatorial methods

for rapidly screening and characterizing new

biomaterials. Specifically, new methods for

rapidly characterizing cell response to polymer

crystallinity, composition, and surface chemistry

have been developed.

Carl G. Simon, Jr. and Newell R. Washburn

Combinatorial and high-throughput methods hold the

potential to accelerate research and development in

any field of scientific study. In the Polymers Division,

we are trying to lead the way in the application of these

approaches to the characterization of biomaterials.

Towards this end, we have utilized gradient technology

to create libraries with varying material properties

focusing specifically on surface energy, polymer

crystallinity, and polymer composition.

Surface energy is a fundamental material property

that affects cell interactions. This response may be

through a direct cell-material interaction, but more

often is an indirect effect where surface energy dictates

 protein adsorption, which subsequently dictates cell

response. An automated stage is used to move a

silanized glass slide beneath a UV lamp to create a

gradient in oxidation from differential exposure to the

UV light. Water contact angles for this gradient surface

varies from 30 ° to 90 °. Cell behavior is assessed

on the gradients, providing a unique tool to probe the

fundamental correlations between cell response and

surface energy.

Combinatorial Methods for Rapid Screening of Biomaterials

Polymer crystallinity: Surface topology can

strongly influence the performance of tissue-engineered

medical products. Crystalline polymers used in

biomedical applications, such as poly(ε-caprolactone)

and poly(L-lactic acid) (PLLA), can have either a

rough or a smooth surface depending upon processing.

To create a gradient in surface topology, polymer

solutions are first spread onto glass substrates to yield

smooth, amorphous, thin films. The films are placed

on a temperature gradient stage such that one end is

held below the glass transition temperature (Tg) at

ambient temperature and the other end is heated

above the Tg to 100 °C. This produces gradients in

crystallinity along the PLLA films where the room

temperature-end remains smooth and amorphous

while the 100 °C-end becomes crystalline and

roughened. When combined with cell culture,

we have a high-throughput method for studying

cell response to the surface roughness that results

from polymer crystallinity.

Polymer composition: Manufacturing industries

have historically used polymer blending as an

inexpensive method to create new materials with

desirable properties. Blending can optimize modulus,

strength, morphology, and crystallinity. For these

reasons, blending is also receiving attention from the

tissue engineering community. A gradient library of

two polymers is created using a three-syringe pump

system and a translation stage. The library is a

strip-shaped film, and its composition is measured by

Fourier Transform Infrared (FTIR) microspectroscopy.

A gradient in composition spans the long axis of the

film being PLLA-rich on one end and PDLLA-rich on

the opposite end. Cells are cultured on the gradients

to yield a high-throughput method for screening cell

response to polymer blends.

The project accomplishments have been presented at

six different symposia and in two journal articles, one of

which was in the top-ranked tissue engineering journal,

Biomaterials. Four other articles have been submitted

or are in preparation. Finally, these activities were

highlighted under “Government News” in Biomaterials

Forum which is a quarterly news bulletin circulated by

the Society for Biomaterials amongst its 1500 members.

Contributors and Collaborators

F.W. Wang, E.J. Amis (Polymers Division, NIST);

N. Eidelman (American Dental Association, NIST);

Y. Deng (Ceramics Division, NIST); K.M. Yamada

(NIDCR/NIH); J. Kohn (Rutgers University);

R. Gross (Polytechnic University)

Figure 1: Atomic Force Microscopy (AFM) height image of

a poly(L-lactic acid) spherulite.
32
33

Program Overview

Materials for Electronics

The U.S. electronics industry faces strong

international competition in the manufacture of smaller,

faster, more functional, and more reliable products.

Many critical challenges facing the industry require

the continual development of advanced materials

and processes. The NIST Materials Science and

Engineering Laboratory (MSEL) works closely with

U.S. industry covering a broad spectrum of sectors

including semiconductor manufacturing, device

components, packaging, data storage, and assembly,

as well as complementary and emerging areas such as

optoelectronics and organic electronics. MSEL has a

multidivisional approach, committed to addressing the

most critical materials measurement and standards

issues for electronic materials. Our vision is to be

the key resource within the Federal Government for

materials metrology development and will be realized

through the following objectives:

■ Develop and deliver standard measurements and data;

■ Develop advanced measurement methods needed by

industry to address new problems that arise with the

development of new materials;

■ Develop and apply in situ as well as real-time, factory

floor measurements, for materials and devices having

micrometer- to nanometer-scale dimensions;

■ Develop combinatorial material methodologies for

the rapid optimization of industrially important

electronic materials;

■ Provide the fundamental understanding of the

divergence of thin film and nanoscale material

properties from their bulk values;

■ Provide the fundamental understanding of materials

needed for future nanoelectronic devices, including

first principles modeling of such materials.

The NIST/MSEL program consists of projects led

by the Metallurgy, Polymers, Materials Reliability, and

Ceramics Divisions. These projects are conducted in

collaboration with partners from industrial consortia

(e.g., International SEMATECH), individual companies,

academia, and other government agencies. The program

is strongly coupled with other microelectronics

programs within the government such as the National

Semiconductor Metrology Program (NSMP). Materials

metrology needs are also identified through the

International Technology Roadmap for Semiconductors

(ITRS), the IPC Lead-free Solder Roadmap, the

National Electronics Manufacturing Initiative (NEMI)

Roadmap, the Optoelectronics Industry Development

Association (OIDA) Roadmap, IPC (the International

Packaging Consortium), and the National [Magnetic

Data] Storage Industry Consortium (NSIC) Roadmap.

In each of these areas, MSEL researchers have made

substantial contributions to the most pressing technical

challenges facing industry, from new fabrication methods

and advanced materials in the semiconductor industry, to

advanced packaging materials, to magnetic data storage.

Below are just a few examples of MSEL contributions

over the past year.

Advanced Gate Dielectrics

To enable further device scaling, the capacitive

equivalent thickness (CET) of the gate stack thickness

must be 0.5 nm to 1.0 nm. This is not achievable with

existing SiO2/polcrystalline Si gate stacks. Given the

large number of possible choices for these new layers,

the only feasible approach to understanding the complex

materials interactions that result at the gate dielectric/

substrate and gate dielectric/metal gate electrode

interfaces is through the application of combinatorial

methodologies. This same methodology and apparatus

are applicable to a wide variety of problems in the

electronic materials field.

Sub-100 nm Nanofabrication

The continual decrease in feature size has been the

driving force for advances in the semiconductor industry.

Current structures have 90 nm dimensions with planned

nodes at 65 nm and 35 nm structures. Advanced

measurements of the patterning materials (photoresists),

are needed to enable future large scale manufacturing of

smaller devices. MSEL utilizes advanced x-ray and

neutron tools to provide insight into the feasibility

and optimization of these important processes.

Advanced Metallization

Electrodeposited copper is rapidly replacing aluminum

for on-chip “wiring” because of its lower electrical

resistivity, superior electromigration behavior, and the

ability to fill fine features without the formation of seams

or voids. As feature dimensions go below 100 nm,

difficulties in maintaining performance are anticipated.

These issues are addressed through a combination of

modeling and experimental efforts.

Test Methods for Embedded Passive Devices

Significant advantages arise if passive devices are

integrated directly into the circuit board as embedded

passive devices rather than discretely attached with

automated assembly. New metrology methods were

developed to address the needs of the electronic industry.

Two test methods were completed and have received

wide acceptance by industry as new methods to accelerate

the development of embedded passive device technology.

Contact: Martin L. Green or

Eric K. Lin (Polymers Division)
34

Materials for Electronics

NIST provides the semiconductor industry with

unique on-wafer measurements of the physical

and structural properties of nanoporous thin films.

Several complementary experimental techniques

are used to measure the pore and matrix

morphology of candidate materials. The data

are used by industry to select candidate low-k

materials. Measurement methods that may be

transferred to industrial laboratories, such as

x-ray porosimetry, are developed. New methods

are being developed to measure patterned low-k

samples and to assess the extent of porous

structure modification caused by plasma etch.

Eric K. Lin and Wen-li Wu

The future generation of integrated circuits requires

porous low-k interlayer dielectric materials to

address issues with power consumption, signal

propagation delays, and crosstalk that decrease device

performance. The introduction of nanometer scale

pores into a solid film lowers its effective dielectric

constant. However, increasing porosity adversely

affects other important quantities such as physical

strength and barrier properties. These effects pose

severe challenges to the integration of porous

dielectrics into the device structure.

There is a need for nondestructive, on-wafer

characterization of nanoporous thin films. Parameters

such as the pore size distribution, wall density, porosity,

film uniformity, elemental composition, coefficient of

thermal expansion, and film density are needed to evaluate

candidate low-k materials. NIST continues to develop

low-k characterization methods using a combination of

complementary measurement methods including small

angle neutron and x-ray scattering (SANS, SAXS), high

resolution x-ray reflectivity (HRXR), x-ray porosimetry

(XRP), SANS porosimetry, and ion scattering. To facilitate

the transfer of measurement expertise, a recommended

practice guide for XRP was completed and will be available

for industrial customers.

In collaboration with industrial and university partners,

we have applied existing methods to new low-k materials

and developed new methods to address upcoming

integration challenges. A materials database developed

in collaboration with International SEMATECH is used

extensively by SEMATECH and its member companies to

help select candidate materials and to optimize integration

processing conditions. This year, we also addressed the

effects of the ashing/plasma etch process on the low-k

material during pattern transfer. Often, surfaces exposed

to ashing/plasma densify and lose terminal groups

(hydrogen or organic moiety) resulting in increased

Characterization of Porous Low-k Dielectric Constant Thin Films

moisture adsorption and, thus, increased dielectric

constant. HRXR measurements enable quantification of

the surface densification or pore collapse in ashing-treated

and/or plasma-treated blanket films.

Figure 1: SAXS data of a test line grating created in a porous

low-k film. Experimental data — solid symbol; model fit — red

line. The top data was fit with a uniform cross-section whereas

the bottom data was fit with a dense skin layer. Regions outlined

by blue circle highlight the difference between these two models.

A new method using SAXS was also developed to

investigate the effect of plasma etch on patterned low-k

films. Any densification of the sidewall may be observable

by x-ray scattering from the cross-section of a patterned

nanostructure. Preliminary SAXS work was carried

out at Argonne National Laboratory using line gratings

of low-k material. The feasibility of this approach is

shown in Figure 1 where a surface layer densification

is needed to fit the SAXS data.

Contributors and Collaborators

H. Lee, C. Soles, R. Hedden, M. Silverstein, T. Hu,

R. Jones, D. Liu, B. Vogt, B. Bauer (Polymers Division,

NIST); C. Glinka (NIST Center for Neutron Research);

Y. Liu (International SEMATECH); Q. Lin, A. Grill,

H. Kim (IBM); M. Ko (LG Chem.); H. Fu (Novellus);

J. Quintana, D. Casa (Argonne National Laboratory);

K. Char, D. Yoon (Seoul National University);

J. Watkins (University of Massachusetts — Amherst)
35

Materials for Electronics

Photolithography, the process used to fabricate

integrated circuits, is the key enabler and driver

for the microelectronics industry. As lithographic

feature sizes decrease to the sub-100 nm length

scale, significant challenges arise because both

the image resolution and the thickness of the

imaging layer approach the macromolecular

dimensions characteristic of the polymers used

in the photoresist film. Unique high-spatial

resolution measurements are developed to

reveal limits on materials and processes that

challenge the development of photoresists for

next-generation sub-100 nm lithography.

Vivek M. Prabhu

Photolithography is the driving technology used by

the microelectronics industry to fabricate integrated

circuits with ever decreasing sizes. In addition,

this fabrication technology is rapidly being adopted

in emerging areas such as optoelectronics and

biotechnology requiring the rapid creation of nanoscale

structures. In this process, a designed pattern is

transferred to the silicon substrate by altering the

solubility of areas of a polymer-based photoresist

thin film through an acid catalyzed deprotection

reaction after exposure to radiation through a mask.

To fabricate smaller features, next generation

photolithography will be processed with shorter

wavelengths of light requiring photoresist films

less than 100 nm thick and dimensional control to

within 2 nm.

To advance this key fabrication technology, we

work closely with industrial collaborators to develop

and apply high-spatial resolution and chemically specific

measurements to understand changes in material

properties, interfacial behavior, and process kinetics

at nanometer scales that can significantly affect the

patterning process.

This year, we have continued to apply and

advance unique measurement methods to provide

structural measurement of fabricated nanoscale

structures and new insight and detail into the complex

physico–chemical processes used in advanced

chemically amplified photoresists. These methods

include x-ray and neutron reflectivity (XR, NR), small

angle x-ray and neutron scattering (SAXS, SANS),

near-edge x-ray absorption fine structure spectroscopy

(NEXAFS), combinatorial methods, solid state nuclear

magnetic resonance (NMR), quartz crystal microbalance

(QCM), fluorescence correlation spectroscopy (FCS),

and atomic force microscopy (AFM).

Polymer Photoresists for Next-Generation Nanolithography

Accomplishments for this past year include:

advancement of photoresist–liquid interfaces for

immersion lithography and developer distribution in

ultrathin films (see highlight); photoresist component

segregation (see Figure 1); quantification of the

post-exposure bake time on the reaction–diffusion of

photoacid 3D deprotection volume; first measurement

of immersion and exposure dependence of the surface

composition of base additives in 193 nm resist films;

identification of key anti-reflective coating (ARC)

components responsible for profile control problems

and residual layer formation at the ARC-resist interface;

quantification of environmental sensitivity by in-situ

processing using NEXAFS; and quantification of the

effects of developer and additives on the final resolution

of lithographic features using a model reaction–front

bilayer geometry.

International SEMATECH has selected NIST in

an effort to apply these fundamental measurements

to identify materials sources of the fabrication limits

of advanced photoresists.

Contributors and Collaborators

B. Vogt, E. Jablonski, C. Soles, W. Wu, C. Wang,

R. Jones, T. Hu, M. Wang, D. VanderHart, C. Chiang,

E. Lin (Polymers Division, NIST); D. Fischer,

S. Sambasivan (Ceramics Division, NIST); S. Satija

(NCNR, NIST); D. Goldfarb, A. Mahorowala,

M. Angelopoulos (IBM T.J. Watson Research Center);

H. Ito (IBM Almaden Research Center); C. Willson

(University of Texas at Austin); R. Puligadda,

C. Devadoss (Brewer Science); R. Dammel,

F. Houlihan (Clariant Corporation)

Figure 1: NEXAFS instrument and spectra illustrating a

homopolymer enrichment at the film surface for a model 157 nm

photoresist blend. The mismatch in surface versus bulk composition

illustrate interfacial limitations for sub 100 nm structures.
36

Materials for Electronics

The field of organic electronics has dramatically

emerged in recent years as an increasingly important

technology encompassing a wide array of devices

and applications including embedded passive

devices, flexible displays, and sensors. Device

performance, stability, and function critically

depend upon charge transport and material

interaction at the interfaces of disparate

materials. We develop and apply non-destructive

measurement methods to characterize the electronic

and interfacial structure of organic electronics

materials with respect to processing methods,

processing variables, and materials characteristics.

Eric K. Lin and Jan Obrzut

Organic electronic devices are projected to

revolutionize integrated circuits through new

applications that take advantage of low-cost, highvolume manufacturing, nontraditional substrates, and

designed functionality. The current state of organic

electronics is analogous to the early stages of the silicon

electronics industry with the concurrent development

of multiple material platforms and processes, and a lack

of measurement standardization between laboratories.

A critical need exists for new diagnostic probes, tools,

and methods to address new technological challenges.

Organic electronics presents fundamentally

different measurement challenges from those identified

for inorganic devices. The adoption of this technology

will be advanced by the development of an integrated

suite of metrologies to correlate device performance

with the structure, properties, and chemistry of

materials and interfaces. We are developing

measurement methods to provide the data and insight

needed for the rational and directed development

of emerging materials and processes.

This year, we have addressed three areas covering

a spectrum of active organic electronic materials:

dielectric measurements for embedded passive devices,

Figure 1: Schematic diagrams of the local structure of

poly 3-hexylthiophene, an organic semiconductor, near an

interface (left) and the architecture for an organic transistor (right).

Organic Electronics

measurements of moisture permeation rates through

barrier films for organic light-emitting diode displays,

and measurements of the orientation and structure of

organic semiconductors for transistor applications.

To meet the metrology needs for embedded

passive devices, two new measurement methods were

successfully developed and will find widespread use

within industry (see Highlight). A NIST-developed Test

Method for Dielectric Permittivity and Loss Tangent of

Embedded Passive Materials from 100 MHz to 12 GHz

was accepted and recommended as a standard test

method. In addition, a new test was developed and

applied for testing passive materials at high electric

fields and voltages.

For organic light-emitting diode displays, a key

measurement challenge is the quantification of the

moisture permeation rates through a barrier coating.

Any moisture able to penetrate the coating compromises

the performance of the device. There is a need

to measure moisture permeation rates as low as

10–6 g/m2 d. In collaboration with Vitex Systems, Inc.,

neutron and x-ray reflectivity measurements demonstrated

the capability of measuring these low permeation rates

in addition to providing spatial detail about the transport

of water within the barrier material itself.

Finally, near-edge x-ray absorption fine structure

(NEXAFS) spectroscopy was applied to several classes

of organic electronics materials to investigate the

electronic structure, chemistry, and orientation of

these molecules near a supporting substrate. NEXAFS

provides a powerful and sensitive method to probe the

interfacial structure that is critical to the performance of

these devices. For example, it was found that several

organic semiconductor molecules preferentially align

“edge-on” rather than “face-down” on solid substrates.

Contributors and Collaborators

D. DeLongchamp, O. Anopchenko, K. Kano, B. Vogt,

H. Lee, E. Jablonski, W. Wu (Polymers Division, NIST);

S. Sambasivan, D. Fischer (Ceramics Division, NIST);

L. Richter (CSTL); C. Richter, E. Vogel (EEEL);

D. McGregor, G.S. Cox, J. Felten (DuPont); D. Fritz

(MacDermid); T. Bergstresser (Gould Electronics);

K. Fjeldsted (Electro Scientific Industries); R. Crosswell

(Motorola); C. Vanderpan (UL); R. Whitehouse (SanminaSCI); L. Moro, N. Rutherford (Vitex); V. Subramanian

(U.C. Berkeley); Z. Bao (Stanford University);

B. Ong (Xerox); A. Afzali (IBM); G. Jabbour (Arizona

State University); R. Pilston (Plextronics); Y. Jung,

Do Yoon (Seoul National University)
37

Materials for Electronics

Nanoimprint Lithography

Nanoimprint lithography (NIL) has emerged as

a viable next generation lithography (NGL)

capable of transferring physical patterns smaller

than 5 nm into a polymeric film.[1] The production

of nanoscale structures enabled by NIL raises new

metrology challenges, as the ability to pattern now

exceeds the ability to measure and/or evaluate

material properties. The objective of this project

is to develop high-resolution metrologies that

facilitate the development of NIL.

Christopher L. Soles and Ronald L. Jones

NIL has recently emerged as one of the leading

NGL candidates for the semiconductor industry.

The 2003 update of the ITRS Semiconductor Roadmap

identifies NIL as a strong candidate lithography for the

45 nm technology node. Silicon Strategies included

Molecular Imprints, Inc. (Austin, TX) and Nanonex

(Princeton, NJ), two major NIL tool companies, in their

“60 Emerging Start-ups” list for 2004. Going beyond

CMOS, MIT’s Technology Review selected NIL as one

of the “10 Emerging Technologies That Will Change

the World.”[2] The cost efficient and high-resolution

nanopattering of NIL will also be beneficial in emerging

technologies such as optical communications, data

storage, bio devices, nano-electromechanical systems

(NEMS), micro-electromechanical systems (MEMS),

and sensors, by enabling low-cost nanofabrication.

The NIL concept is elegantly simple. A master pattern

with sub-100 nm features is fabricated into a hard material

(Si, quartz, Ni, etc.) using high-resolution (but slow)

patterning, such as e-beam lithography. The patterns are

then transferred into a resist by stamping the hard master

mold into a softer polymer or monomer film. The pattern

is “set” into the resist film with either heat, to facilitate

flow into the mold features, or by using a monomeric

(liquid-like) film that cross-links in the mold. These imprints

can be repeated multiple times using a single master, greatly

reducing the cost of ownership.

One of the greatest challenges facing NIL is to quantify

the fidelity of pattern transfer; traditional shape metrologies

struggle when feature sizes approach 5 nm. We are

developing critical dimension small angle X-ray scattering

(CD-SAXS) to quantify 3-D pattern shape, with sub-nm

resolution. Since CD-SAXS uses high-energy X-rays that

penetrate Si and most mold materials, we can quantify

pattern shape in the master mold, on the mold in contact

with the resist, and in the final pattern (i.e., fidelity of

pattern transfer), as depicted in Figure 1.

Figure 2: CD-SAXS data (intensity versus scattering vector) for

parallel lines and spaces imprinted into a PMMA film.

Figure 1: CD-SAXS quantification of the nanoimprint process.

Figure 2 illustrates CD-SAXS data for parallel lines

and spaces imprinted into a poly(methyl methacrylate)

(PMMA) film. The data are in black, while the red line

is a fit to a trapezoidal cross section. By tilting the

sample and fitting several data sets, we determine that

the pattern pitch is (253 ± 1) nm, the average line

width is (146 ± 1) nm, the trapezoid side-wall angle is

(4.2 ± 0.5) °, and line height is (180 ± 1) nm.

By providing such accurate structural information, we

enable the quantitative evaluation and improvement of

imprint processes. Furthermore, we are also developing

complementary mechanical and physical property

measurements for imprinted polymeric nanostructures.

Understanding the unique properties that arise in these

nanostructures is crucial to engineering functional

and robust polymeric devices at the nanoscale.

References

1. M.D. Austin, et al., Appl. Phys. Lett. 84, 5299 (2004).

2. Technology Review, Feb, 42–44 (2003).

Contributors and Collaborators

W. Wu, T. Hu (Polymers Division, NIST);

S. Hooker, C. Flannery (Materials Reliability Division,

NIST); S. Pang (University of Michigan); C.G. Willson

(UT Austin); L. Koecher (Nanonex); D. Resnick,

K. Nordquist (Motorola)
38
39

Program Overview

Nanometrology

in determining mechanical properties of thin films

and nanostructures, focuses on developing traceable

calibration methodologies and standard test methods.

We also use atomic force acoustic microscopy,

surface acoustic wave spectroscopy, and Brillouin light

scattering to measure the mechanical properties of

thin films. In addition, we are developing micro- and

nano-scale structures and test methods to measure

strength and fracture behavior of interfaces and

materials having very small volumes.

The chemical and structural characterization and

imaging utilize neutron and x-ray beam lines at three

facilities: the NCNR; the National Synchrotron Light

Source at Brookhaven National Laboratory; and

the Advanced Photon Source at Argonne National

Laboratory. Innovative scattering and spectroscopy

methods are advancing our ability to obtain a wide

range of chemical and structural information at the

nanoscale, including chemical bond identification and

orientation, polyelectrolyte dynamics, and equilibrium

structures. In collaboration with three other NIST

laboratories, we are developing electron microscopy

and spectroscopy instrumentation for quantitative,

3D chemical imaging at the nanoscale. Other

characterization projects include work on gradient

reference specimens for the calibration of advanced

scanning probe microscopy, and the application of

carbon nanotubes as physical probes of cell membranes.

Efforts in the fabrication and monitoring of

nanoscale processes and events include the study of

electrochemical and microfluidic methods for fabricating

nanostructures, novel approaches to nanocalorimetry

for the study of interfacial reactions, in situ observations

of nanoparticle and nanotube dispersion and alignment,

and advanced instrumentation for nanotribology

experiments.

Finally, we have extensive efforts in the theory,

modeling, and prediction of material properties and

behavior extending from nanoscale to macroscale

dimensions. Modeling efforts include large-scale finite

element methods, multiscale Green’s function methods,

classical atomistic simulations, first principles, and

quantum mechanical calculations using density

functional theory. Often, several modeling methods

must be combined into one study to accurately describe

the material behavior; thus, we pay great attention to

the correct interfacing between models operating at

different length scales, to ensure that our models

properly capture the physics of both components

and total systems.

Contact: Douglas T. Smith, Stephen M. Hsu, or

Michael J. Fasolka (Polymers Division)

The burgeoning field of nanomaterials extends

across the full range of traditional material classes,

including all forms of metals, polymers, and ceramics.

No previous materials technology has shown so

prodigiously a potential for concurrent advances in

research and industry as does the field of nanomaterials

in mechanical devices, electronic, magnetic, and optical

components, quantum computing, tissue engineering

and other biotechnologies, and as-yet unanticipated

exploitations of as-yet undiscovered novel properties

of nanoscale assemblies of particles. Already, there

is growing excitement surrounding the ability of

some molecules or particles to self-assemble at

the nanoscale to form new materials with unusual

properties. Nanometrology, i.e., the ability to conduct

measurements at these dimensions, to characterize the

materials, and to elucidate the structure and nature of

these new and novel assemblies, is a requisite and

fundamental cornerstone that must be established

securely if this technology is to flourish.

NIST is uniquely positioned to lead the development

of the measurement methods, instrumentation, standards,

and reference materials that, together, will form the

metrological infrastructure essential to the success

of nanotechnology.

The MSEL Nanometrology Program incorporates

basic measurement metrologies to determine material

properties, process monitoring at the nanoscale,

nanomanufacturing and fabrication techniques, and

structural characterization and analysis techniques

such as advanced imaging and multiscale modeling.

The Program comprises 22 projects in the Ceramics,

Materials Reliability, Metallurgy, and Polymers

Divisions, and includes structural characterization

using neutron scattering at the NIST Center for

Neutron Research (NCNR). The projects cover a

wide range of measurement and characterization

methods grouped into the areas of mechanical

property measurement, chemical and structural

characterization and imaging, fabrication and monitoring

of nanoprocesses and events, and modeling of nanoscale

properties. In each area, we work to advance basic

measurement capabilities and lead the intercomparison,

standardization, and calibration of test methods. The

newly completed Advanced Measurement Laboratory

at the NIST Gaithersburg site provides an incomparable

environment for accurate nanoscale metrology.

In the area of mechanical property measurement,

we are developing and standardizing techniques for

determining nanoscale elastic properties (elastic moduli,

Poison’s ratio, and internal stress), plastic deformation,

density, adhesion, friction, stiction, and tribological

behavior. Work in nanoindentation, used extensively
40

Nanometrology

Axisymmetric adhesion tests promise a powerful

means to quantify adhesive performance with

the simultaneous ability to visualize debonding

mechanisms. However, industrial adoption of

these techniques has been slow, since traditional

axisymmetric testing equipment does not allow

rapid assessment of product performance

over a large parameter space. In response,

we are developing instruments that permit

high-throughput (and high value) measurements

of adhesion across combinatorial libraries.

Aaron M. Forster and Seung-ho Moon

Adhesion is governed by surface interactions

 and the mechanical properties of the adhesive.

Axisymmetric adhesion (ASA) measurements, such as

JKR[1] methods and “probe tack” tests, provide powerful

means for quantifying these contributions to adhesion,

while providing visual insight into the mechanisms by

which adhesives fail. However, current ASA instruments

are geared towards serial testing of single specimens.

This “one-at-a-time” paradigm is incompatible with

industry research, which increasingly requires methods

to rapidly and thoroughly measure large numbers of

adhesive formulations. Our objective is to produce

ASA measurement instruments that operate in a

high-throughput manner, while retaining the high-value

data these methods produce. These tools enable the

rapid identification of structure–property relationships

critical for adhesive performance, thereby assisting

industry in developing new adhesive formulations.

This report describes two of the high-throughput ASA

instruments that have been built to address these issues.

The JKR method employs a hemispherical lens that

is pressed into a specimen. Tracking the lens/specimen

contact area versus load or lens displacement yields

the work of adhesion. Our instrument, the Multilens

Combinatorial Adhesion Test (MCAT) employs an array

Combinatorial Adhesion and Mechanical Properties:

Axisymmetric Adhesion Testing

Figure 1: a) Contact area map of MCAT lens array. Each circle

represents data for a separate measurement. b) Contact area vs.

displacement data for a single lens array element. The red line is

the fit to JKR theory, which yields the work of adhesion.

of microlenses to conduct multiple JKR-type adhesion

tests in parallel. By simultaneously tracking the

contact radii of each element of the lens array, up

to 400 measurements of the work of adhesion are collected

in the time required for a single traditional JKR test

(see Figure 1). When MCAT is used in conjunction

with gradient combinatorial specimen libraries, each

lens measures a different adhesive system. We recently

benchmarked MCAT measurements of the work of

adhesion between glass and silicone against single lens

JKR tests, with excellent agreement.

Figure 2: a) Schematic of CPT adhesion test instrument.

b) Adhesion energy (W) of a model PSA vs. temperature. Inset:

Image of probe/sample contact shows debonding of the PSA.

The adhesion of viscoelastic materials, such as pressure

sensitive adhesives (PSAs), is not described well by

JKR-type tests. Probe tack tests provide quantitative

adhesion measurements for viscoelastic systems with

simultaneous visualization of debonding events. We

developed a new combinatorial probe tack (CPT) test

for the measurement of PSA formulation performance

(Figure 2). A key feature of the instrument, a gradient

hot-stage, enables rapid assessment of temperature effects.

Temperature is an important processing parameter and

environmental factor for PSAs. Our CPT testing of PSAs

(Figure 2) rapidly provides quantitative adhesion energy

data and debonding images as a function of temperature.

The device design significantly reduces experimental

uncertainties associated with fabrication of multiple

samples, and reduces the overall measurement time

significantly, while maintaining high-quality, rich datasets.

We are currently refining the CPT instrument and testing

its use towards a variety of applications such as UV-cured

PSAs and epoxy systems.

Reference

1. K.L. Johnson, K. Kendall, and A.D. Roberts,

Proceedings of the Royal Society of London A:

Materials 324, 301 (1971).

Contributors and Collaborators

A. Chiche, C.M. Stafford, W.L. Wu, W. Zhang

(Polymers Division, NIST)
41

Nanometrology

Combinatorial Adhesion and Mechanical Properties:

Innovative Approaches to Peel Tests

Figure 1: Master adhesion map delineating critical surface

energy conditions for adhesion vs. a reduced time-temperature

function, at .

as a function of substrate surface energy, annealing time,

and annealing temperature (see Figure 1). This defines

an operating window of temperature, time, and surface

energy to ensure proper adhesion of a thin polymer film

to the material of interest.

Peel testing is the primary tool industry uses to

gauge adhesive performance, but current peel

test methods involve “one-at-a-time” analysis of

single specimens. Our research aims to accelerate

adhesive performance testing by developing

devices and measurement strategies that meld

the peel test construct with combinatorial and

high-throughput (C&HT) methods.

Christopher M. Stafford and Martin Y.M. Chiang

As part of the mission of the NIST Combinatorial

 Methods Center (NCMC), we are developing

C&HT peel-test methods that enable rapid assessment

of adhesion within the large parameter space associated

with adhesive formulation and processing. This report

describes two milestones we have met in this endeavor.

Our first achievement involves a NIST-developed

experiment design for measuring adhesion of a polymer

layer to an underlying substrate in a combinatorial manner.

This test method utilizes the peel-test geometry to

investigate the interfacial failure between a thin polymer

film and a silicon substrate as a function of annealing time

and temperature, as well as the substrate surface energy.

Combinatorial libraries are generated by using the existing

NCMC gradient toolkits: a polymer film is coated onto

a substrate containing a surface energy gradient, and

this sample is subsequently exposed to an orthogonal

temperature gradient.[1] To further extend the parameter

space available in this study, we incorporated annealing

time as a third dimension. This requires fabricating

multiple identical samples and successively annealing each

sample for longer times. By applying the Williams–Landel–

Ferry (WLF) time-temperature superposition, we can

construct a master curve (failure map) detailing the

transition from adhesion (bonded) to failure (debonded)

Figure 2: a) Force vs. distance curve for a typical peel test; and

b) distribution curve of the force data.

Our second achievement addresses a challenge

in applying the peel test to combinatorial specimens:

the lack of ample statistical information that is the

foundation of this type of measurement. For example,

a conventional peel test conducted under constant

conditions results in a fluctuating force to be averaged.

Applying a continuous gradient of sample properties

or test conditions in the peel direction implies that each

data point (force) corresponds to a given test condition,

thus prohibiting the average force to be calculated

for a given condition. To address this issue, we have

developed a simple statistical treatment that allows

a relationship between the uncertainty of the force

and the domain size to be established. This treatment

ultimately will dictate the number of data points required

to obtain acceptable uncertainties in the measurement.

These studies demonstrate how combinatorial

approaches can be applied to characterize adhesion

using a peel test blueprint. In doing so, we have

designed a new statistical tool to assist in defining the

gradient step size (discrete gradients) or gradient

steepness (continuous gradients) that allows ample

statistical information to be obtained.

Reference

1. For details, see A. Seghal, et al., Microscopy Today

11 (6), 26–29 (2003).

Contributors and Collaborators

A. Chiche, R. Song, A. Karim (Polymers Division,

NIST); J. Filliben (Statistical Engineering Division, NIST)
42

Nanometrology

Engineering of nanomaterials, biomaterials,

and nano-electromechanical systems hinges on

techniques for imaging complex nano-structures.

In this respect, new Scanned Probe Microscopy

(SPM) methods promise nano-scale mapping of

chemical, mechanical, and electro-optical properties,

but these techniques generally only offer qualitative

information. Through a suite of reference specimens

fabricated with a combinatorial design, we aim to

calibrate image data from emerging SPM methods,

thereby advancing these nanometrology tools.

Michael J. Fasolka and Duangrut Julthongpiput

Recent years have seen the development of a new

generation of SPM techniques, which intend to

measure chemical, mechanical, and electro–optical

properties on the nanoscale. However, contrast in new

SPM images is difficult to quantify since probe fabrication

can be inconsistent and probe/sample interactions are not

understood. Our research at the NIST Combinatorial

Methods Center (NCMC) aims to provide a suite of

reference specimens for the quantification of next

generation SPM data. By design, our specimens will gauge

the quality of custom-made SPM probes, calibrate SPM

image contrast through “traditional” surface measurements

(e.g., spectroscopy, contact angle) and provide information

for understanding complex probe/sample interactions. Our

specimens are produced with bench-top microfabrication

routes and combinatorial gradient methods developed

by the NCMC. Here, combinatorial methods are key

since they enable the fabrication of specimens that vary

properties that govern SPM image contrast in a systematic,

independent manner. Moreover, as opposed to traditional

reference specimens, combinatorial samples provide not

one, but a multitude of calibration conditions.

Figure 1 illustrates principles of our specimen design

through a specific case useful for quantifying chemically

sensitive SPM techniques such as friction-force SPM,

Gradient Reference Specimens for Advanced

Scanned Probe Microscopy

Figure 1: Schematic illustration of our gradient reference

specimen for chemically sensitive SPM techniques.

Figure 2: Preliminary calibration curve relating friction force SPM

image contrast to differences in surface energy (γ ), as determined

from a single gradient reference specimen. The minimum contrast

point (red arrow) illuminates the sensitivity of the probe.

or Chemical Force Microscopy, which employs a

custom-made probe. The crux of this specimen is

a “gradient micropattern” (∇-μp): a series of micronscale lines that continuously change in their chemical

properties (e.g., surface energy) compared to a constant

matrix. Two “calibration fields” adjacent to the ∇-μp

directly reflect the chemistry of the lines and the matrix.

Thus, traditional measurements (e.g., contact angle)

along the calibration fields (1) gauge local chemical

differences in the ∇-μp and thereby (2) calibrate

contrast in SPM images acquired along the ∇-μp.

Figure 2 demonstrates use of this specimen for

calibrating friction force SPM image contrast. We

fabricate this specimen via microcontact printing of a

chlorosilane self-assembled monolayer (SAM) on a SiO2

matrix. The chemical gradient is achieved via a graded

UV-ozonolysis of the SAM. The plot abscissa gives the

difference in friction force (contrast) between the lines

and matrix for SPM images collected along the ∇-μp.

The ordinate expresses the corresponding surface energy

(γ) data (from contact angle measurements) collected

along the calibration fields. Thus, from a single specimen

we create a comprehensive calibration curve that relates

SPM friction force to differences in surface energy.

Moreover, the plot neatly illuminates the smallest

γ difference sensed by the probe (red arrow), which is

useful for gauging the quality of custom-made probes.

Currently, we are refining this reference specimen

design, and we are developing similar designs for other

advanced SPM methods.

Contributors and Collaborators

K. Beers (Polymers Division, NIST);

D. Hurley (Materials Reliability Division, NIST);

T. Nguyen (Materials and Construction Research

Division, BFRL); S. Magonov (Veeco/Digital

Instruments)
43

Nanometrology

Wet nanomanufacturing is the generation of

novel nanostructures and the control of chemical

reactions (and signals) in a fluid environment;

this requires effective techniques and efficient

material measurements. Therefore, we aim to

develop sophisticated fluid-handling devices for

directing material assembly, controlling material

transport, and measuring material properties.

Steven D. Hudson

Flow control is essential for fluid measurement and

manufacturing applications. The type and strength of

flow are often crucial for producing the desired structure

and properties when assembling advanced materials. Using

recent advances in microfluidic technology, we have

developed a miniature tool without moving parts that

mimics the function of a four-roll mill, a rheological and

processing instrument.[1] Several microchannels converge

to the measurement zone, where micro-particle-image

velocimetry was used to map the flow field. By adjusting

the relative flow rates, the full range of planar linear flows

could be produced. This includes simple shear, which

is inaccessible in the four-roll mill.

Wet Nanomanufacturing

Figure 1: Carbon nanotube clusters suspended in the microfluidic

trap in extensional flow in the horizontal direction. The cluster at

right has fractured from the main one. Also, an individual tube

that has broken from the cluster is visible at the far left (arrow).

Individual tubes have also been trapped and examined in flow.

Most importantly, this new device works as a trap,

so that particles and other objects can be examined in

flow. Using this and related devices, clusters of carbon

nanotubes suspended in fluids have been examined

(Figure 1). In addition, extension and alignment of

individual wormlike micelles has been measured as a

function of flow strength and duration.

To achieve certain flow characteristics for particular

measurement applications, other microchannel geometries

have been and are being developed. Specifically, a

device for measuring cell and tissue viability, and

mechanical response, is being assembled. Also, a new

instrument system for measuring interfacial tension

has been developed.

Although microchannels are effective for these

important functions, reaching a smaller scale efficiently,

requires a new approach. Miniaturization towards

nanochannels is usually not practical, because it

necessitates very high pressures. At these smaller

scales, membranes mediated by pores (as found in

living systems) are likely to be efficient means to

control the transport of material in metrological and

nanomanufacturing processes.

Figure 2: Molecular model of the artificial membrane pore

viewed from: a) the side, b) top, and c) in cross section.

One such membrane pore (Figure 2) assembled

by supramolecular chemistry has been characterized

recently.[2] Determination of Fourier components

(amplitude and phase) by transmission electron

microscopy demonstrated that the supramolecular

assemblies are tubular, with an inner diameter of 1.4 nm.

Proton conduction through these channels has been

measured to be comparable to the transmembrane

protein channel gramacidin. Directed assembly of

other artificial transmembrane channels will be explored.

References

1. Hudson, et al., Applied Physics Letters 85, (2004).

2. Percec, et al., Nature, in press (2004).

Contributors and Collaborators

F. Phelan Jr., K. Migler, P. Start, P. Stone, J. Taboas,

E. Hobbie, E. Amis, J. Cabral, K. Beers, J. Douglas,

J. Pathak (Polymers Division, NIST); J. Kasianowicz

(Biotechnology Division, NIST); V. Percec, D. Discher

(University of Pennsylvania); R. Tuan (NIH)
44

Nanometrology

Polyelectrolytes differ in chain dynamics and

equilibrium structure from neutral polymers due to

long-range electrostatic interactions. This manifests

into strongly interacting solutions for both synthetic

and biopolymers, as observed by associative

behavior and multi-mode relaxations. Origins

of these relaxations require new experimental

methods probing the local structure and dynamics.

Vivek M. Prabhu and Eric J. Amis

Polymeric templates are found throughout nature

most commonly in the nucleic acid base-pairing

of DNA. This special hydrogen bond template

has currently been explored for design of novel

nanostructured materials. New routes to self-assembled

or template-assisted assembly using externally supplied

fields such as electric, flow, magnetic, and patterned

substrates must overcome Brownian motion as well as

structural correlations between and among molecules.

For polyelectrolytes, such as DNA, the long-ranged

electrostatic interactions also contribute to the solution

structure in addition to the local and directional hydrogen

bond associations. The distribution and dynamics of

the counterion species about a polyelectrolyte serve as

a starting point to understand the interactions governing

controlled assembly and complement the often-studied

polymer structure point-of-view.

We have established, using neutron scattering

experiments performed at the NIST Center for

Neutron Research (NCNR), the remarkable ability for

counterions to essentially conform to linear flexible

polyelectrolytes. This was accomplished by direct

measure of the counterion partial static and dynamic

structure factor highlighting the coupled polymer and

counterion association for model synthetic materials

shown below.

Characterization of Counterion Association with

Polyelectrolytes: Novel Flexible Template Behavior

An example of the counterion correlations is shown

by the SANS structural peak in Figure 1. The peak

illustrates the counterion correlations mediated by

the chain. By tuning the range of the electrostatic

interactions with added NaCl, an “invisible” salt,

the influence is two-fold: (1) the electrostatics are

screened, and the solution returns to neutral-like

behavior; and (2) at higher salt concentrations, the

Na+ displace the visible h-TMA+ counterions as shown

in the accompanying schematic. Although the polymer

template is no longer observed, its influence is still

observed with a “visible” salt.

The counterion dynamics are length scale

dependent and slow down near the correlation peak.

This behavior illustrates that the polyion-counterion

motions are coupled at the nanoscale. Hence, the

role of counterions also serves as a design criteria in

assembling structures. Unique labeling has provided

a new viewpoint of charged polymer solution structure

and dynamics. This project aims to characterize the

role of charged polymer topology with branched

materials, networks, and gels on the coupled dynamics

to assess the parameters governing template-assisted

assembly. Modern simulation and theoretical insight

will assist in understanding these challenges for

nanoscale assembly.

Contributors and Collaborators

D. Bossev, N. Rosov (NIST Center for Neutron

Research)

Small-angle neutron scattering (SANS) was used to

characterize the equilibrium structure, while neutron

spin echo (NSE) spectroscopy was used to examine the

dynamics occurring at length scales between (60 and 3)

nm and time scales between 45 ps to 100 ns.

Figure 1: “Visible” organic counterions associate with the negatively

charged chain at low salt and are displaced by added “invisible”

sodium ions for fixed polymer concentration of 24.9 gL–1.
45

Program Overview

Safety and Reliability

While various structural failures have captured

national attention over the years, the events of

September 11, 2001 generated a greatly increased

awareness of vulnerabilities in our national

infrastructure. The extent of these vulnerabilities

depends to a large degree on the performance of

materials in situations outside of the original design

considerations. It is now recognized that a critical

and urgent national need exists to establish the

behavior of materials under such extreme loadings,

and to disseminate guidance and tools to assess and

reduce future vulnerabilities.

The goal of providing a technical basis for cost-effective

changes to national practices and standards, coupled with

a need for an integrated effort drawing on capabilities and

expertise of a broad collaborative team, has lead to the

development of the Safety and Reliability Program within

MSEL. This program draws on the expertise of several

divisions in MSEL and across NIST.

Project selection is guided by an identification and

assessment of the particular vulnerabilities within our

materials-based infrastructure, and focusing on those

issues which would benefit strongly by improved

measurements, standards, and materials data. Ultimately,

we intend to moderate the effects of acts of terrorism,

natural disasters, or other emergencies, all through

improved use of materials.

Our vision is to be the key resource within the Federal

Government for materials metrology development as

realized through the following objectives:

■ Identify and address vulnerabilities and needed

improvements in U.S. infrastructure;

■ Develop and deliver standard measurements and data;

■ Develop advanced measurement methods needed by

industry to address new problems that arise with the

development of new materials;

■ Support other agency needs for materials expertise.

This program responds both to customer requests

(primarily other government agencies) and to the

Department of Commerce 2005 Strategic Goal of

“providing the information and framework to enable

the economy to operate efficiently and equitably.”

For example, engineering design can produce safe and

reliable structures only when the property data for the

materials is available and accurate. Equally important,

manufacturers and their suppliers need to agree on

how material properties should be measured.

The Safety and Reliability Program works toward

solutions to measurement problems on scales ranging

from the macro to the micro, in three of the Laboratory’s

Divisions (Materials Reliability, Metallurgy, and Polymers).

The scope of activities includes the development and

innovative use of state-of-the-art measurement systems;

leadership in the development of standardized test

procedures and traceability protocols; development of

an understanding of materials in novel conditions; and

development and certification of Standard Reference

Materials (SRMs). Many of the tests involve extreme

conditions, such as high rates of loading, high temperatures,

or unusual environments (e.g., deep underwater). These

extreme conditions often produce physical and mechanical

properties that differ significantly from the handbook

values for their bulk properties under traditional conditions.

These objectives will be realized through innovative

materials, property measurement and modeling.

The MSEL Safety and Reliability Program is

also contributing to the development of test method

standards through committee leadership roles in

standards development organizations such as the

ASTM International and the International Standards

Organization (ISO). In many cases, industry also

depends on measurements that can be traced to NIST

Standard Reference Materials (SRM®).

In addition to the activities above, all three divisions

provide assistance to various government agencies on

homeland security and infrastructural issues. Projects

include assessing the performance of structural steels

as part of the NIST World Trade Center Investigation,

advising the Bureau of Reclamation on metallurgical issues

involving pipelines and dams, advising the Department of

the Interior on the structural integrity of the U.S.S. Arizona

Memorial, and collaborating with both the Department

of Transportation and the Department of Energy on

pipeline safety issues.

Contact: Thomas A. Siewert, Frank W. Gayle, or

Chad R. Snyder (Polymers Division)
46

Ballistic-resistant body armor has been credited

with saving more than 2,500 lives, but new

materials are constantly being developed, and

there currently exists no method for evaluating

armor over time to ensure the continued

effectiveness of the protection. The objective of

this project is to prevent catastrophic failure of

personal body armor by developing a standard

test method for reliability of the active polymeric

materials that comprise them.

Chad R. Snyder and Gale A. Holmes

This research is focused primarily on two goals:

(1) to link chemical structure and fiber mechanics

to ballistic performance; and (2) to identify chemical

mechanisms underlying reduction of ballistic

performance, such as UV degradation and hydrolysis.

Currently, one of the most promising models linking

fiber mechanical properties to ultimate ballistic

resistance is the work of Cunniff and Auerbach.[1]

From a dimensional analysis study, these researchers

concluded that the principal fiber property of interest in

relating the ballistic performance of any armor system

material to any penetrator, independent of system areal

density, is the (U*)1/3 parameter, which is the product

of fiber specific toughness and strain wave velocity

and is expressed in m/s, i.e.,

 (1)

Ballistic Resistance of Polymeric Materials

Safety and Reliability

Figure 1: Single fiber fragmentation testing instrument.

Figure 2: Single fiber data obtained on single E-glass fibers.

Most tests of ballistic fiber strength are performed on

yarns rather than single fibers. However, obtaining yarns

from vests currently in service tends to be very invasive

and decreases the strength of the vest. Obtaining single

fibers is far less invasive and, therefore, provides a potential

mechanism for monitoring vests while in service without

comprising the integrity of the vests. Because of recent

research in our laboratory into polymer composites, there

are a number of instruments available to conduct tests on

single fibers. One such instrument is an automated single

fiber fragmentation testing machine (see Figure 1), which

allows us to obtain stress, strain, and modulus. In the

past, resin samples containing a single carbon or glass

fiber were put into the machine. For this project, we

have developed a method to characterize isolated fibers

without a resin matrix.

where σ is the fiber ultimate axial tensile strength, ε is

the fiber ultimate tensile strain, ρ is the fiber density,

and E is the linear elastic fiber modulus. This model

has recently been given a firmer theoretical framework

by Phoenix and Portwal.[2]

To verify the capability to measure isolated ballistic

fibers, we have recently completed measurements on

isolated glass fibers (Figure 2). The results are within

the predicted limits, and testing is ongoing on single

ballistic fibers. To address the influence of chemical

structure on ballistic fiber performance and durability,

model compounds are being prepared to identify any

UV and/or hydrolytic degradation pathways of the

fibers through mass, infrared, and nuclear magnetic

resonance spectroscopies.

References

1. P.M. Cunniff and M.A. Auerback, 23rd Army Science

Conference, Assistant Secretary of the Army

(Acquisition, Logistics and Technology), Orlando,

FL (December 2002).

2. S.L. Phoenix and P.K. Porwal, International Journal

of Solids and Structures 40, 6723 (2003).

Contributors and Collaborators

B. Fanconi, K. Flynn, D. Liu, W. McDonough,

D. VanderHart, W. Wallace (Polymers Division, NIST);

K. Rice (Office of Law Enforcement Standards, NIST)

 

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47

Polymers Division FY04 Annual Report Publication List

Polymers Division FY04 Annual Report Publication List

Characterization and Measurement —

Internal Capabilities/Method Development

Gelation, Diffusion and the Glass Transition

M. Aichele, Y. Gebremichael, F.W. Starr,

J. Baschnagel, and S.C. Glotzer, “Polymer-Specific

Effects of Bulk Relaxation and Stringlike Correlated

Motion in the Dynamics of a Supercooled Polymer

Melt,” Journal of Chemical Physics 119, 5290–5304

(2003).

M. Aichele, Y. Gebremichael, F.W. Starr,

J. Baschnagel, and S.C. Glotzer, “Publisher’s Note:

‘Polymer-Specific Effects of Bulk Relaxation and

Stringlike Correlated Motion in the Dynamics of a

Supercooled Polymer Melt’ (Vol. 119, p. 5290, 2003),”

Journal of Chemical Physics 120, 6798 (2004).

A. Batra, R.C. Hedden, P. Schofield, A. Barnes,

C. Cohen, and T.M. Duncan, “Conformational Behavior

of Guest Polymer Chains in Uniaxially Stretched

Poly(diethylsiloxane) Elastomers: 2H NMR and

SANS,” Macromolecules 36, 9458–9466 (2003).

D. Bedrov, G.D. Smith, and J.F. Douglas,

“Structural and Dynamic Heterogeneity in a Telechelic

Polymer Solution,” Polymer 45, 3961–3966 (2004).

G. Caliskan, D. Mechtani, J.H. Roh, A. Kisliuk,

A.P. Sokolov, S. Azzam, M.T. Cicerone, S. Lin–Gibson,

and I. Peral, “Protein and Solvent Dynamics: How

Strongly are They Coupled?” Journal of Chemical

Physics 121, 1978–1983 (2004).

N. Giovambattista, S.V. Buldyrev, F.W. Starr, and

H.E. Stanley, “Connection between Adam–Gibbs

Theory and Spatially Heterogeneous Dynamics,”

Physical Review Letters 90, 085506-(1–4) (2003).

E.H. Kang, M.L. Mansfield, and J.F. Douglas,

“Numerical Path–Integration Technique for the

Calculation of Transport Properties of Proteins,”

Physical Review E 69, 031918:1–11 (2004).

N. Lacevic, F.W. Starr, T.B. Schroder, and

S.C. Glotzer, “Spatially Heterogeneous Dynamics

Investigated via a Time-dependent Four-point Density

Correlation Function,” Journal of Chemical Physics

119, 7372–7387 (2003).

S. Lin–Gibson, H.J. Walls, S.B. Kennedy, and

E.R. Welsh, “Reaction Kinetics and Gel Properties

of Blocked Diisocyanate Cross-Linked Chitosan

Hydrogels,” Carbohydrate Polymers 54, 193–199

(2003).

P.S. Niranjan, P.B. Yim, J.G. Forbes, S.C. Greer,

J. Dudowicz, K.F. Freed, and J.F. Douglas,

“The Polymerization of Actin: Thermodynamics

near the Polymerization Line,” Journal of Chemical

Physics 119, 4070–4084 (2003).

V.M. Prabhu, N.S. Rosov, and E.J. Amis,

“Organic Counterion Statics and Dynamics Studied by

Small-angle Neutron Scattering and Neutron Spin Echo

Spectroscopy,” Journal of Chemical Physics (in press).

H.E. Stanley, M.C. Barbosa, S. Mossa, P.A. Netz,

F. Sciortino, F.W. Starr, and M. Yamada, “Statistical

Physics and Liquid Water at Negative Pressures,”

Physica A — Statistical Mechanics and Its Applications

315, 281–289 (2002).

F.W. Starr, C.A. Angell, E. La Nave, S. Sastry,

A. Scala, F. Sciortino, and H.E. Stanley, “Recent

Results On The Connection Between Thermodynamics

And Dynamics In Supercooled Water,” Biophysical

Chemistry 105, 573–583 (2003).

Nanoscale Science, Engineering and Technology

E.K. Hobbie, “Optical Anisotropy of Nanotube

Suspensions,” Journal of Chemical Physics (in press).

P.M. McGuiggan and S.M. Wiederhorn, “Workshop:

Nanometrology of Materials,” NISTIR 7037 (2003).

K. Shin, H. Wang, S.K. Satija, C.C. Han, D. Josell,

and J.E. Bonevich, “Rapid Deformation of Thin

Gold Layers in Polymer Matrices Studied by X-ray

Reflectivity,” Journal of Applied Physics 94, 2115–2122

(2003).

F.W. Starr, J.F. Douglas, and S.C. Glotzer,

“Origin of Particle Clustering in a Simulated Polymer

Nanocomposite and Its Impact on Rheology,”

Journal of Chemical Physics 119, 1777–1788 (2003).

K. Yurekli, A. Karim, E.J. Amis, and

R. Krishnamoorti, “Influence of Layered-Silicates on

the Phase-Separated Morphology of PS-PVME Blends,”

Macromolecules 36, 7256–7267 (2003).

Polymer Blends

J. Dudowicz, K.F. Freed, and J.F. Douglas, “Lattice

Model of Equilibrium Polymerization. IV. Influences

of Activation, Chemical Initiation, Chain Scission and

Fusion and Chain Stiffness on Polymerization and

Phase Separation,” Journal of Chemical Physics 119,

12645–12666 (2003).
48

Polymers Division FY04 Annual Report Publication List

J. Dudowitz, K.F. Freed, and J.F. Douglas,

“Flory–Huggins Model of Equilibrium Polymerization

and Phase Separation in the Stockmayer Fluid,”

Physical Review Letters 92, 045502:1–4 (2004).

A. Indrakanti, R.L. Jones, and S.K. Kumar,

“Do ‘Nonequilibrium’ Effects Control Strong Surface

Segregation from Polymer Blends?” Macromolecules

37, 9–12 (2004).

G. Matsuba, K. Shimizu, H. Wang, Z.G. Wang,

and C.C. Han, “Kinetics of Phase Separation and

Crystallization in Poly(ethylene-ran-hexene) and

Poly(ethylene-ran-octene),” Polymer 44, 7459–7465

(2003).

H. Wang, J.F. Douglas, S.K. Satija, R.J. Composto,

and C.C. Han, “Early-Stage Compositional Segregation

in Polymer Blend Films,” Physical Review E 67,

061801:1–6 (2003).

K. Yurekli, A. Karim, E.J. Amis, and R. Krishnamoorti,

“Phase Behavior of PS-PVME Nanocomposites,”

Macromolecules 37, 507–515 (2004).

Polymer Composites

M.Y. Chiang and M. Fernandez–Garcia, “Relation

of Swelling and Tg Depression to the Apparent Free

Volume of a Particle-Filled Epoxy-Based Adhesive,”

Journal of Applied Polymer Science 87, 1436–1444

(2003).

K.P. Chong and M.Y.M. Chiang, “Research and

Challenges in Applied Mechanics,” in 14th US National

Congress of Theoretical and Applied Mechanics,

June 2002, Blacksburg, VA.

G.A. Holmes, E. Feresenbet, and D. Raghavan,

“Using Self-Assembled Monolayer Technology to Probe

the Mechanical Response of the Fiber Interphase–Matrix

Interphase Interface,” Composite Interfaces 10,

515–546 (2003).

G.A. Holmes, J.H. Kim, C.K. Moon, and

W.G. McDonough, “Coordinated Fracture and Failure

Initiation in Microcomposites,” in ICCE-10, July 2003,

New Orleans, LA.

G.A. Holmes, W.G. McDonough, J.P. Dunkers,

and C.C. Han, “Interaction between Matrix Cracks in

E-Glass/Epoxy Two-Dimensional Multi-Fiber-Array

Model Composites,” Journal of Polymer Science

Part B: Polymer Physics 41, 2976–2981 (2003).

G.A. Holmes, R.C. Peterson, D.L. Hunston, and

W.G. McDonough, “E-Glass/DGEBA/m-PDA Single

Fiber Composites: Interface Debonding During Fiber

Fracture,” Polymer Composites (in press).

W.G. McDonough, K.M. Flynn, D.L. Hunston,

and J.P. Dunkers, “A Test Method to Determine the

Fiber and Void Contents of Carbon/Glass Hybrid

Composites,” Journal of ASTM International 1, (2004).

X. Wang, M.Y.M. Chiang, and C.R. Snyder,

“Monte-Carlo Simulation for the Fracture Behavior

of Unidirectional CFRP at Different Temperatures,”

Composites Part A: Applied Science and

Manufacturing (in press).

Polymer Crystallization

D.L. VanderHart, E. Perez, A. Bello, J. Vasquez,

and R. Quijada, “Effect of Tacticity on the Structure

of Poly(1-octadecane),” Polymer (in press).

Characterization and Measurement —

Standards and Data

Polymer Standards

C.M. Guttman and W.R. Blair, “Recertification

of SRM 1483a, a Polyethylene,” NIST SP 260–158

(in press).

C.M. Guttman, W.R. Blair, B.M. Fanconi,

R.J. Goldschmidt, W.E. Wallace, S.J. Wetzel, and

D.L. VanderHart, “Certification of a Polystyrene

Synthetic Polymer, SRM 2888,” NIST SP 260–152

(2003).

J.A. Tesk, “Reference Materials for Tissue

Engineered Medical Products,” in Tissue Engineering

(in press).

J.A. Tesk and L.R. Karam, “NIST and Standards

for Tissue Engineered Medical Products,” in Tissue

Engineered Medical Products, (TEMPS), edited by

E. Schutte, G.L. Picciolo, and D.S. Kaplan (ASTM

International, West Conshohocken, PA 2003).

Mass Spectrometry

B.J. Bauer and K.M. Flynn, “MALDI of Structured

Polymer Particles,” in Proceedings of the 51st ASMS

Conference on Mass Spectrometry and Allied Topics,

June 2003, Montreal, Canada.

B.J. Bauer, K.M. Flynn, and B.D. Vogt, “MALDI

of Layered Polymer Films,” ACS Polymeric Materials:

Science and Engineering Preprints 90, 457–458,

March 2004, Anaheim, CA.
49

Polymers Division FY04 Annual Report Publication List

H.C.M. Byrd, C.M. Guttman, S. Robinson, and

D.P. Ridge, “Molecular Mass Determination of

Saturated Hydrocarbons Using Organometallic

Ion Chemistry,” in Proceedings of the 51st ASMS

Conference on Mass Spectrometry and Allied Topics,

June 2003, Montreal, Canada.

J.E. Girard, M. Konaklieva, J. Gu, C.M. Guttman,

and S.J. Wetzel, “Characterization of Linear and

Branched Polyethylenimine (PEI) by ESI-MS and

MALDI-TOF-MS,” in Proceedings of the 51st ASMS

Conference on Mass Spectrometry and Allied Topics,

June 2003, Montreal, Canada.

C.M. Guttman, B.J. Bauer, K.L. Beers,

S.A. Bencherif, H.C.M. Byrd, and S. Lin–Gibson,

“MALDI-TOF MS Analysis of Chain-End

Functionalized Polymers,” in Proceedings of the

51st ASMS Conference on Mass Spectrometry and

Allied Topics, June 2003, Montreal, Canada.

S.D. Hanton, I.Z. Hyder, J.R. Stets, K.G. Owens,

W.R. Blair, C.M. Guttman, and A.A. Giuseppetti,

“Investigations of Electrospray Sample Deposition

for Polymer MALDI Mass Spectrometry,” Journal

of the American Society for Mass Spectrometry 15,

168–179 (2004).

A.J. Kearsley, W.E. Wallace, J. Bernal, and

C.M. Guttman, “Automated Peak Picking and

Integration Algorithm for Mass Spectral Data,”

in Proceedings of the 51st ASMS Conference on

Mass Spectrometry and Allied Topics, June 2003,

Montreal, Canada.

A.J. Kearsley, W.E. Wallace, and C.M. Guttman,

“A Numerical Method For Mass Spectral Data

Analysis,” Applied Mathematics Letters (in press).

W.E. Wallace, C.M. Guttman, S.J. Wetzel, and

S.D. Hanton, “Mass Spectrometry of SyntheticPolymer Mixtures Workshop,” Rapid Communications

in Mass Spectrometry 18, 518–521(2004).

W.E. Wallace, A.J. Kearsley, and C.M. Guttman,

“An Operator–Independent Approach to Mass Spectral

Peak Identification and Integration,” Analytical

Chemistry 76, 2446–2452 (2004).

S.J. Wetzel, C.M. Guttman, and K.M. Flynn, “The

Influence of Electrospray Deposition in Matrix-assisted

Laser Desorption/Ionization Mass Spectrometry

Sample Preparation for Synthetic Polymers,” Rapid

Communications in Mass Spectrometry 18, 1139–1146

(2004).

S.J. Wetzel, C.M. Guttman, and J.E. Girard,

“A Study of the Effects of Matrix and Laser Energy

on the Molecular Mass Distribution of Synthetic

Polymers,” in Proceedings of the 51st ASMS Conference

on Mass Spectrometry and Allied Topics, June 2003,

Montreal, Canada.

S.J. Wetzel, C.M. Guttman, and J.E. Girard,

“The Influence of Matrix and Laser Power on the

Molecular Mass Distribution of Synthetic Polymers

obtained by MALDI,” International Journal of Mass

Spectrometry (in press).

Electronics Materials

Polymers for Lithography

C. Devadoss, Y. Wang, R. Puligadda, J.L. Lenhart,

E.L. Jablonski, D.A. Fischer, S. Sambasivan, E.K. Lin,

and W.L. Wu, “Investigation of BARC-Resist Interfacial

Interactions,” in SPIE Proceedings: Optical

Lithography, February 2003, Santa Clara, CA.

C. Harrison, J.A. Dagata, and D.H. Adamson,

“Lithography with Self-Assembled Block Copolymer

Microdomains,” in Developments in Block Copolymer

Science and Technology, edited by I.W. Hamley

(John Wiley & Sons, Ltd., 2004) Chap. 9, pp. 295–323.

T. Hu, R.L. Jones, W.L. Wu, E.K. Lin, Q. Lin, and

J. Quintana, “Small Angle X-ray Scattering Metrology

for Sidewall Angle and Cross Section of Nanometer

Scale Line Gratings,” Applied Physics Letters (in press).

T. Hu, R.L. Jones, W.L. Wu, C.L. Soles, E.K. Lin,

M. Arpan, and D.M. Casa, “Fast Evaluation of

Next-Generation Lithographical Patterns by Small

Angle X-ray Scattering,” ACS Polymer Preprints 44(2),

541–542, September 2003, New York, NY.

E.L. Jablonski, J.L. Lenhart, S. Sambasivan,

D.A. Fischer, R.L. Jones, E.K. Lin, W.L. Wu,

D.L. Goldfarb, K. Temple, M. Angelopoulos, and

H. Ito, “NEXAFS Measurements of the Surface

Chemistry of Chemically Amplified Photoresists,”

in Proceedings of the International Conference on

Characterization and Metrology for ULSI Technology,

March 2003, Austin, TX.

E.L. Jablonski, V.M. Prabhu, S. Sambasivan,

E.K. Lin, D.A. Fischer, D.L. Goldfarb, M. Angelopoulos,

and H. Ito, “Near Edge X-ray Absorption Fine Structure

Measurements of Surface Segregation in 157 nm

Photoresist Blends,” Journal of Vacuum Science and

Technology 21, 3162–3165 (2003).
50

Polymers Division FY04 Annual Report Publication List

E.L. Jablonski, S. Sambasivan, E.K. Lin,

D.A. Fischer, C. Devadoss, and R. Puligadda, “Near

Edge X-Ray Absorption Fine Structure Measurements

of the Interface between Bottom Antireflective Coatings

and a Model Deprotected Photoresist,” Journal of

Vacuum Science and Technology 21, 3153–3156 (2003).

R.L. Jones, T. Hu, E.K. Lin, W.L. Wu, R. Kolb,

D.M. Casa, P.J. Bolton, and G.G. Barclay, “Small

Angle X-ray Scattering for Sub-100 nm Pattern

Characterization,” Applied Physics Letters 83,

4059–4061 (2003).

R.L. Jones, T.J. Hu, E.K. Lin, W.L. Wu, D.M. Casa,

and G.G. Barclay, “3-Dimensional Lineshape Metrology

using Small Angle X-ray Scattering,” in Proceedings

of the International Conference on Characterization

and Metrology for ULSI Technology, March 2003,

Austin, TX.

R.L. Jones, T.J. Hu, V.M. Prabhu, C.L. Soles,

E.K. Lin, W.L. Wu, D.L. Goldfarb, and M. Angelopoulos,

“Form of Deprotection in Chemically Amplified Resists,”

in Proceedings of the International Conference on

Characterization and Metrology for ULSI Technology,

March 2003, Austin, TX.

R.L. Jones, V.M. Prabhu, D.L. Goldfarb, E.K. Lin,

C.L. Soles, J.L. Lenhart, W.L. Wu, and M. Angelopoulos,

“Correlation of the Reaction Front with Roughness in

Chemically Amplified Photoresists,” in Symposia of

the American Chemical Society, (American Chemical

Society, Washington, DC, in press).

J.L. Lenhart, D.A. Fischer, S. Sambasivan, E.K. Lin,

R.L. Jones, C.L. Soles, W.L. Wu, D.L. Goldfarb, and

M. Angelopoulos, “X-ray Absorption Spectroscopy

to Probe Interfacial Issues in Photolithography,”

in Proceedings of SPIE — Microlithography,

February 2003, Santa Clara, CA.

J.L. Lenhart, D.A. Fischer, S. Sambasivan, E.K. Lin,

C.L. Soles, R.L. Jones, W.L. Wu, D.L. Goldfarb,

and M. Angelopoulos, “Utilizing Near Edge X-ray

Absorption Fine Structure to Probe interfacial issues

in Photolithography,” in Special Issue of the 2002

ACS Symposium on Microelectronics, August 2002,

Boston, MA.

C.L. Soles, R.L. Jones, J.L. Lenhart, V.M. Prabhu,

W.L. Wu, E.K. Lin, D.L. Goldfarb, and M. Angelopoulos,

“Polymer Dynamics and Diffusive Properties in

Ultra-thin Photoresist Films,” in Proceedings of SPIE —

The International Society of Optical Engineering,

5039 I, 366–375, February 2003, Santa Clara, CA.

D.L. VanderHart, V.M. Prabhu, and E.K. Lin,

“Proton NMR Determination of Miscibility in a Bulk

Model Photoresist System: Poly(4-hydroxystyrene)

and the Photoacid Generator, Di-(t-butylphenyl)

Iodonium Perfluorooctane Sulfonate,” Chemistry of

Materials (in press).

B.D. Vogt, C.L. Soles, R.L. Jones, C.Y. Wang,

E.K. Lin, W.L. Wu, S.K. Satija, D.L. Goldfarb, and

M. Angelopoulos, “Interfacial Effects on Moisture

Absorption in Thin Polymer Films,” Langmuir 20,

5285–5290 (2004).

M.X. Wang, E.K. Lin, A. Karim, and M.J. Fasolka,

“Combinatorial Methods Study of Confinement Effects

on the Reaction Front in Ultrathin Chemically Amplified

Photoresists,” in Characterization and Metrology for

ULSI Technology: 2003 International Conference,

CP683, 448–452, March 2003, Austin, TX.

M.X. Wang, V. Prabhu, E.K. Lin, M.J. Fasolka, and

A. Karim, “Chemically Amplified Resist Fundamentals

Studies by Combinatorial Approaches,” ACS Polymeric

Materials: Science and Engineering, 90, 810–811,

March 2003, Anaheim, CA.

Porous Low-k Dielectric Thin Films

O. Escorcia, R.C. Hedden, H.-J. Lee, and

C. Waldfried, “Comparison of Curing Processes for

Porous Dielectrics Measurement from Specular X-ray

Reflectivity,” Journal of the Electrochemical Society

(in press).

R.C. Hedden, H.J. Lee, and B.J. Bauer,

“Characterization of Nanoporous Low-k Thin Films

by Small Angle Neutron Scattering Contrast Variation,”

Langmuir 20, 416–422 (2004).

R.C. Hedden, H.J. Lee, C.L. Soles, and B.J. Bauer,

“Characterization of Pore Structure in a Nanoporous

Low-Dielectric Constant Thin Film by Neutron

Scattering Porosimetry and X-ray Porosimetry,”

Langmuir ASAP, (2004).

R.C. Hedden, H.J. Lee, C.L. Soles, and B.J. Bauer,

“Pore Size Distributions in Low-k Dielectric Thin Films

from SANS Porosimetry,” ACS Polymeric Materials:

Science and Engineering Preprints, 90, 494– 495,

March 2004, Anaheim, CA.

H.J. Lee, C.L. Soles, D.W. Liu, B.J. Bauer,

E.K. Lin, and W.L. Wu, “Structural Characterization

of Methylsilsesquioxane-Based Porous Low-k using

X-ray Porosimetry,” in International Interconnect

Technology Conference (IITC) Proceeding, June 2003,

Burlingame, CA.
51

Polymers Division FY04 Annual Report Publication List

H.J. Lee, C.L. Soles, D.W. Liu, B.J. Bauer, E.K. Lin,

W.L. Wu, and A. Grill, “Structural Characterization of

Porous Low-k Thin Films Prepared by Different

Processing Techniques using X-ray Porosimetry,”

Journal of Applied Physics 95, 2355–2359 (2004).

E.K. Lin, H.J. Lee, B.J. Bauer, H. Wang, J.T. Wetzel,

and W.L. Wu, “Structure and Property Characterization

of Low-k Dielectric Porous Thin Films Determined by

X-ray Reflectivity and Small-angle Neutron Scattering,”

in Springer Series in Advanced Microelectronics, Low

Dielectric Constant Materials for IC Applications,

edited by P.S. Ho, J. Leu, and W.W. Lee (Springer

Publishing Inc., 2003), Chap. 3, pp. 75–93.

M.S. Silverstein, B.J. Bauer, H.J. Lee, R.C. Hedden,

B. Landes, J. Lyons, B. Kern, J. Niu, and T. Kalantar,

“The Structural Evolution of Pore Formation in Low-k

Dielectric Thin Films,” in Proceedings of the International

Conference on Characterization and Metrology for

ULSI Technology, March 2003, Austin, TX.

C.L. Soles, H.J. Lee, R.C. Hedden, D.W. Liu,

B.J. Bauer, and W.L. Wu, “X-ray Reflectivity

Porosimetry for the Characterization of Porous Low-k

Dielectric Constant Thin Films,” in Proceedings of

the International Conference on Characterization

and Metrology for ULSI Technology, March 2003,

Austin, TX.

W.L. Wu, E.K. Lin, and C.L. Soles, “Structure

Characterization of Porous Interlevel Dielectric Films,”

FUTURE FAB International 17, 113 (2004).

Dielectric Characterization/Electronic Packaging

J. Obrzut and A. Anopchenko, “High Frequency

Input Impedance Characterization of Dielectric Films

for Power-Ground Planes,” IEEE Transactions on

Instrumentation and Measurement 52, 1120–1124

(2003).

J. Obrzut and A. Anopchenko, “Input Impedance

of a Coaxial Line Terminated with a Complex Gap

Capacitance — Numerical and Experimental Analysis,”

IEEE Transactions on Instrumentation and

Measurement (in press).

J. Obrzut, A. Anopchenko, K. Kano, and H. Wang,

“High Frequency Loss Mechanism in Polymers Filled

with Dielectric Modifiers,” Materials Research Society

Symposium Proceedings, 783, B3.5.1–6 (2003).

J. Obrzut and K. Kano, “Measurement of Complex

Impedance at High AC Voltages using Waveforms,” in

IEEE IMTC 2004 — Instrumentation and Measurement

Technical Conference, 3, 1994–1997, May 2004,

Como, Italy.

Polymer Thin Film Fundamentals

T.A. Germer and M.J. Fasolka, “Characterizing

Surface Roughness in Thin Films by Polarized Light

Scattering,” in Advanced Characterization Techniques

for Optics, Semiconductors and Nanotechnologies,

Proceedings of the SPIE, 5188, August 2003,

San Diego, CA.

R. Hartschuh, Y. Ding, J.H. Roh, A. Kisliuk,

A.P. Sokolov, C.L. Soles, R.L. Jones, T.J. Hu, W.L. Wu,

and A.P. Mahorowala, “Brillouin Scattering Studies of

Polymeric Nanostructures,” Journal of Polymer

Science Part B — Polymer Physics 42, 1106–1113 (2004).

C.L. Soles, J.F. Douglas, R.L. Jones, and W.L. Wu,

“Unusual Expansion and Contraction in Ultra-Thin

Glassy Polycarbonate Films,” Macromolecules 37,

2901–2908 (2004).

C.L. Soles, J.F. Douglas, W.L. Wu, H. Peng, and

D.W. Gidley, “A Broad Perspective on the Dynamics of

Highly Confined Polymer Films,” in Materials Research

Society Symposium Proceedings, 710, DD3.7.1–6, 2002.

C.L. Soles, J.F. Douglas, W.L. Wu, H.G. Peng,

and D.W. Gidley, “Comparative Specular X-ray

Reflectivity, Positron Annihilation Lifetime

Spectroscopy and Incoherent Neutron Scattering

Measurements of the Dynamics in Thin Polycarbonate

Films,” Macromolecules 37, 2890–2900 (2004).

B.D. Vogt, E.K. Lin, W.L. Wu, and C.C. White,

“Effect of Film Thickness on the Validity of the

Sauerbrey Equation for Hydrated Polyelectrolyte Films,”

Journal of Physical Chemistry B (in press).

B.D. Vogt, C.L. Soles, H.J. Lee, E.K. Lin, and

W.L. Wu, “Confinement Effects on Moisture Absorption

Kinetics in Polyelectrolyte Films,” ACS Polymeric

Materials: Science and Engineering Preprints, 89,

194–195, September 2003, New York, NY.

B.D. Vogt, C.L. Soles, H.J. Lee, E.K. Lin, and

W.L. Wu, “Moisture Absorption and Absorption Kinetics

in Polyelectrolyte Films: Influence of Film Thickness,”

Langmuir 20, 1453–1458 (2004).

C.Y. Wang, V.M. Prabhu, C.L. Soles, B.D. Vogt,

W.L. Wu, E.K. Lin, and S.K. Satija, “Interdiffusion in

Polystyrene and End-Functional Polystyrene Thin Films

Near a Solid Surface,” ACS Polymeric Materials:

Science and Engineering Preprints, 89, 258–259,

New York, NY, September 2003.

W.L. Wu, S. Sambasivan, C.Y. Wang, W.E. Wallace,

J. Genzer, and D.A. Fischer, “A Direct Comparison

of Surface and Bulk Chain-Relaxation in Polystyrene,”

The European Physical Journal E 12, 127–132 (2003).
52

Polymers Division FY04 Annual Report Publication List

Biomaterials

Tissue Engineering Metrology

S. Lin–Gibson, M.L. Becker, K.S. Wilson, and

N.R. Washburn, “Synthesis and Characterization of

Bioactive PEGDM Hydrogels,” ACS Polymer Preprints,

August 2004, Philadelphia, PA.

S. Lin–Gibson, S. Bencherif, J.A. Cooper,

N.R. Washburn, and J.M. Antonucci, “Synthesis

and Characterization of PEG and PEG Urethane

Dimethacrylate Hydrogels,” ACS Polymeric Materials:

Science and Engineering Preprint, 90, 251–252,

March 2004, Anaheim, CA.

S. Lin–Gibson, S. Bencherif, J.A. Cooper,

S.J. Wetzel, J.M. Antonucci, B.M. Vogel, F. Horkay,

and N.R. Washburn, “Synthesis and Characterization

of PEG Dimethacrylates and their Hydrogels,”

Biomacromolecules 5, 1280–1287 (2004).

S. Lin–Gibson, R.L. Jones, N.R. Washburn,

and F. Horkay, “Structure-Property Relationships

of PEGDM Hydrogels,” ACS Polymer Preprints,

August 2004, Philadelphia, PA.

Y. Mei, K.L. Beers, H.C.M. Byrd, D.L. VanderHart,

and N.R. Washburn, “Solid-Phase ATRP Synthesis of

Peptide-Polymer Hybrids,” Journal of the American

Chemical Society 126, 3472–3476 (2004).

Y. Mei, A. Kumar, W. Gao, R. Gross, S.B. Kennedy,

N.R. Washburn, E.J. Amis, and J.T. Elliott,

“Biocompatibility of Sorbitol-Containing Polyesters.

Part I. Synthesis, Surface Analysis and Cell Response

in vitro,” Biomaterials 25, 4195–4201 (2004).

C.G. Simon Jr., W.F. Guthrie, and F.W. Wang,

“Cell Seeding into Calcium Phosphate Cement,” Journal

of Biomedical Materials Research 68A, 628–639

(2004).

F.W. Wang, C.A. Khatri, and J.F. Hsii, “PolymerFilled Calcium Phosphate Cement: Mechanical Properties

and Controlled Release of Growth Factor,” in Advances

in Bioengineering — 2003, Book Number 100679,

BED-Vol. 55, 401, November 2003, Washington, DC.

F.W. Wang, C.A. Khatri, J.F. Hsii, S. Hirayama, and

S. Takagi, “Polymer-Filled Calcium Phosphate Cement:

Mechanical Properties and Controlled Release of

Growth Factor,” in Biomedical Engineering: Recent

Developments, edited by J. Vossoughi (in press).

N.R. Washburn, C.G. Simon Jr., M.D. Weir,

L.O. Bailey, S.B. Kennedy, and E.J. Amis,

“Combinatorial Screen of Cell-Material Interactions,”

ACS Polymeric Materials: Science and Engineering,

90, 759, April 2004, Anaheim, CA.

N.R. Washburn, K.M. Yamada, C.G. Simon Jr.,

S.B. Kennedy, and E.J. Amis, “High-Throughput

Investigation of Osteoblast Response to Polymer

Crystallinity: Influence of Nano-scale Roughness on

Proliferation,” Biomaterials 25, 1215–1224 (2004).

H.H.K. Xu and C.G. Simon Jr., “Self-Hardening

Calcium Phosphate Cement-mesh Composite:

Reinforcement, Micropores and Cell Response,”

Journal of Biomedical Materials Research 69A,

267–278 (2004).

H.H.K. Xu and C.G. Simon Jr., “Self-hardening

Calcium Phosphate Composite Scaffold for Bone Tissue

Engineering,” Journal of Orthopedic Research 22,

535–543 (2004).

H.H.K. Xu, D.T. Smith, and C.G. Simon Jr.,

“Strong and Bioactive Composites Containing Nanosilica-fused Whiskers for Bone Repair,” Biomaterials

25, 4615–4626 (2004).

K. Zhang, S. Lin–Gibson, C.G. Simon Jr.,

J.M. Antonucci, and N.R. Washburn, “Biocompatible

Polymer Blends Derived from the Photopolymerization

of Polyethylene Glycol Dimethacrylate-Polylactide

Mixtures,” ACS Polymer Preprints, August 2004,

Philadelphia, PA.

Dental Materials

J.M. Antonucci, S. Dickens, B.O. Fowler,

H.H.K. Xu, and W.G. McDonough, “Chemistry of

Silanes: Interfaces in Dental Polymers and Composites,”

in Proceedings of the Academy of Dental Materials

Annual Meeting, October 2003, Charleston, SC.

C.A. Khatri, F.W. Wang, and C.G. Simon Jr.,

“Mechanical Properties, Biocompatibility and Controlled

Release of Transforming Growth Factor from Composite

Bone Grafts Consisting of Calcium Phosphate Cement

and Biodegradable Particulates,” in Proceedings of the

Adhesion Society, February 2003, Hilton Head, SC.

C.A. Khatri, J.W. Stansbury, C.R. Schultheisz, and

J.M. Antonucci, “Synthesis, Characterization and

Evaluation of Urethane Derivatives of Bis-GMA,”

Dental Materials 19, 584–588 (2003).

W.G. McDonough, J.M. Antonucci, J.P. Dunkers, and

G.E. Schumacher, “Glass–fiber/resin Interfacial Strength:

The Microbond Test and Chemical Evaluation,” in

Proceedings of the Academy of Dental Materials

Annual Meeting, October 2003, Charleston, SC.

O. Okuno, K. Asaoka, and J.A. Tesk, “HighTemperature Investments,” in Dental Materials and

Their Selection, edited by W.J. O’Brien (Quintessence

Publishing Co., Inc., 2002), Chap. 19, pp. 258–266.
53

Polymers Division FY04 Annual Report Publication List

W.F. Regnault, R.M. Fitzgerald, J.M. Antonucci, and

D. Skrtic, “Effect of Fluid Environment on Ion Release

from Amorphous Calcium Phosphate Filled Restorative

Materials,” ACS Polymer Preprints, August 2004,

Philadelphia, PA.

N.R. Richards, S.H. Dickens, and J.M. Antonucci,

“Dental Polymeric Composites Activated with

Camphorquinone or Diacyl Phosphine Oxide

Photoinitiators,” in Proceedings of the 6th International

Biorelated Polymers Symposium and ACS Meeting,

August 2004, Philadelphia, PA.

D. Skrtic, J.M. Antonucci, E.D. Eanes, and

N. Eidelman, “Dental Composites based on Hybrid and

Surface-modified Amorphous Calcium Phosphate,”

Biomaterials 25, 1141–1150 (2004).

D. Skrtic, J.M. Antonucci, W.G. McDonough,

and D.W. Liu, “Effect of Chemical Structure and

Composition of the Resin Phase on Mechanical

Strength and Vinyl Conversion of Amorphous Calcium

Phosphate-based Composites,” Journal of Biomedical

Materials Research 68A, 763–772 (2004).

E.A. Wilder, J.B. Quinn, and J.M. Antonucci,

“Organogelators and their Application in Dental

Materials,” ACS Polymer Preprints, August 2004,

Philadelphia, PA.

K.S. Wilson and J.M. Antonucci, “StructureProperty Relationships of Thermoset Methacrylate

Composites for Dental Materials: Study of the

Interfacial Phase of Silica Nanoparticle-Filled

Composites,” ACS Polymer Preprints, August 2004,

Philadelphia, PA.

H.H.K. Xu, G.E. Schumacher, F.C. Eichmiller,

R.C. Peterson, J.M. Antonucci, and H.J. Mueller,

“Continuous-Fiber Preform Reinforcement of Dental

Resin Composite Restorations,” Dental Materials 19,

523–230 (2003).

Characterization

L.O. Bailey, N.R. Washburn, C.G. Simon Jr.,

E.S. Chan, and F.W. Wang, “Quantification of

Inflammatory Cellular Responses using Real-Time

Polymerase Chain Reaction,” Journal of Biomedical

Materials Research 69A, 305–313 (2004).

M.L. Becker, L.O. Bailey, and N.R. Washburn,

“Quantitative Response Measurements of Cell Substrate

Interactions via RT-PCR,” ACS Polymer Preprints,

45(1), 92–93, March 2004, Anaheim, CA.

M.E. Broz, D.L. VanderHart, and N.R. Washburn,

“Structure and Mechanical Properties of

Poly(D,L-lactic acid)/Poly(ε-caprolactone) Blends,”

Biomaterials 24, 4181–4190 (2003).

M.T. Cicerone, J.P. Dunkers, and N.R. Washburn,

“Towards in-situ Monitoring of Cell Growth in Tissue

Engineering Scaffolds: High Resolution Optical

Techniques,” in Tissue Engineered Medical Products

(TEMPs) ASTM STP, 1452, November 3, 2002, Miami

Beach, FL.

M.T. Cicerone and C.L. Soles, “Fast Dynamics and

Stabilization of Proteins: Binary Glasses of Trehalose

and Glycerol,” Biophysical Journal 86, 3836–3845

(2004).

J.D. Dunkers, M.T. Cicerone, and N.R. Washburn,

“Collinear Optical Coherence and Confocal

Fluorescence Microscopies for Tissue Engineering,”

Optics Express 11, 3074–3079 (2003).

J.P. Dunkers and M.T. Cicerone, “Scaffold

Structure and Cell Function Through Multimodal

Imaging and Quantitative Visualization,” Biomaterials

Forum 25, 8 (2003).

J.P. Dunkers, M.T. Cicerone, F.A. Landis, and

N.R. Washburn, “A New Metrology for Tissue

Engineering: Collinear Optical Coherence and Confocal

Fluorescence Microscopies,” in Trends in Optics and

Photonics Series (TOPS) Post Conference Digest,

Conference on Lasers & Electro Optics (CLEO), 89,

June 2003, Baltimore, MD.

J.P. Dunkers, M.T. Cicerone, and N.R. Washburn,

“Collinear Optical Coherence Microscopy and Confocal

Fluorescence Microscopy: A New in Vitro Technique

for Tissue Engineering,” in Engineering Tissue Growth

International Conference and Exposition, Conference

Compilation, March 2003, Pittsburgh, PA.

T.W. Kee and M.T. Cicerone, “A Simple Approach

to One-Laser, Broadband CARS Microscopy,” Optics

Letters (in press).

Processing Characterization

Complex Polymer Flow and Instabilities

A.J. Bur and S.C. Roth, “Fluorescence Temperature

Measurements: Methodology for Applications to

Processing,” Polymer Engineering and Science 44,

898–908 (2004).

A.J. Bur and S.C. Roth, “Real-Time Monitoring

of Fluorescence Anisotropy and Temperature during

Processing of Biaxially Stretched Polypropylene Film,”

Polymer Engineering and Science 44, 805–813 (2004).

A.J. Bur, S.C. Roth, M.A. Spalding, D.W. Baugh,

K.A. Koppi, and W.C. Buzanowski, “Temperature

Gradients in the Channels of a Single-Screw Extruder,”

Polymer Engineering and Science (in press).
54

Polymers Division FY04 Annual Report Publication List

J.G. Hagedorn, N.S. Martys, and J.F. Douglas,

“Breakup of a Fluid Thread in a Confined Geometry:

Droplet-Plug Transition, Perturbation Sensitivity and

Kinetic Stabilization with Confinement,” Physical

Review E 69, 056312:1–18 (2004).

E.K. Hobbie, S. Lin–Gibson, H. Wang, J.A. Pathak,

and H. Kim, “Ubiquity of Domain Patterns in Sheared

Viscoelastic Fluids,” Physical Review E 69, 061503:1–5

(2004).

S.D. Hudson, A.M. Jamieson, and B.E. Burkhart,

“The Effect of Surfactant on the Efficiency of ShearInduced Drop Coalescence,” Journal of Colloid and

Interface Science 265, 409–421 (2003).

S.B. Kharchenko, S.G. Hatzikiriakos, and K.B. Migler,

“Conventional Polymer Processing Additives,” in

Polymer Processing Instabilities: Control and

Understanding, edited by S.G. Hatzikiriakos and

K.B. Migler (Marcel Dekker, in press).

S.B. Kharchenko, P.M. McGuiggan, and K.B. Migler,

“Flow Induced Coating of Fluoropolymer Additives:

Development of Frustrated Total Internal Reflection

Imaging,” Journal of Rheology 47, 1523–1545 (2003).

P.M. McGuiggan, “Friction and Adhesion

Measurements between a Fluorocarbon Surface and

a Hydrocarbon Surface in Air,” in Adhesion Society

Extended Abstracts, February 2003, Myrtle Beach, SC.

P.M. McGuiggan, “Friction and Adhesion

Measurements between a Fluorocarbon Surface and

a Mydrocarbon Surface in Air,” Journal of Adhesion

(in press).

M.G. Meillon, D. Morgan, D. Bigio, S.B. Kharchenko,

K.B. Migler, and S. Oriani, “Eliminating Surface Melt

Fracture Using PPA: The Role of PPA Domain Size,”

in Proceedings of the Annual Technical Meeting of

the Society of Plastics Engineers, 96–100, May 2004,

Chicago, IL.

K.B. Migler, “Sharkskin Instability in Extrusion,” in

Polymer Processing Instabilities: Understanding and

Control, edited by S.G. Hatzikiriakos and K.B. Migler

(Marcel Dekker, in press), Chap. 5.

K.B. Migler and S.G. Hatzikiriakos, “Overview

of Processing Instabilities,” in Polymer Processing

Instabilities: Understanding and Control, edited by

S.G. Hatzikiriakos and K.B. Migler (Marcel Dekker,

in press), Chap. 1.

K.B. Migler and S.G. Hatzikiriakos, “Preface,” in

Polymer Processing Instabilities: Understanding and

Control, edited by S.G. Hatzikiriakos and K.B. Migler

(Marcel Dekker, in press).

J.A. Pathak and K.B. Migler, “Droplet-String

Deformation and Stability During Microconfined

Shear Flow,” Langmuir 19, 8667–8674 (2003).

J.A. Pathak and K.B. Migler, “Novel Microstructure

in Polymer Blends Sheared under Confinement,”

Polymer News 376–383 (2003).

Nanoscale Manufacturing

S.D. Hudson, F.R. Phelan Jr., M.D. Handler,

J.T. Cabral, and K.B. Migler, “Microfluidic Analogue

of the 4-Roll Mill,” Applied Physics Letters (in press).

P.M. McGuiggan and D.J. Yarusso, “Measurement

of the Loss Tangent of a Thin Polymeric Film using

the Atomic Force Microscope,” Journal of Materials

Research 19, 387–395 (2004).

V. Percec, A. Dulcey, Y. Miura, U. Edlund,

V.S.K. Balagurusamy, S.D. Hudson, P.A. Heiney,

H. Duan, S.N. Magonov, and S.A. Vinogradov,

“Self-Assembling Amphiphilic Dendritic Dipeptides

that Mimic Helical Protein Pores,” Nature (in press).

F.R. Phelan Jr. and S.D. Hudson, “Flow Simulation

of a Microfluidic Analog of the Four-Roll Mill,”

in Proceedings of the 2004 NSTI Nanotechnology

Conference and Trade Show, 1, 288–291, March 2004,

Boston, MA.

F.R. Phelan Jr. and S.D. Hudson, “Modeling of a

Microfluidic Analog of the Four-roll Mill for Materials

Characterization,” in Proceedings of the Annual

Technical Meeting of the Society of Plastics Engineers,

1054–1058, May 2004, Chicago, IL.

Nanoscale Processing

S. Bourbigot, D.L. VanderHart, J.W. Gilman,

W.H. Awad, R.D. Davis, A.B. Morgan, and C.A. Wilkie,

“Investigation of Nanodispersion in PolystyreneMontmorillonite Nanocomposites by Solid-State NMR,”

Journal of Polymer Science Part B: Polymer Physics

41, 3188–3213 (2003).

A.J. Bur, Y.H. Lee, and S.C. Roth, “Real-time

Dielectric Measurements and Microstructure of

Polymer/Clay Nanocomposites,” in Proceedings of the

Annual Technical Meeting of the Society of Plastics

Engineers, 1284–1288, May 2004, Chicago, IL.

A.J. Bur, Y.H. Lee, S.C. Roth, and P.R. Start,

“Polymer/Clay Nanocomposites Compounding:

Establishing an Extent of Exfoliation Scale Using

Real-Time Dielectric, Optical and Fluorescence

Monitoring,” ACS Polymer Preprints, August 2004,

Philadelphia, PA.
55

Polymers Division FY04 Annual Report Publication List

A.J. Bur, S.C. Roth, Y.H. Lee, N. Noda, and

M. McBrearty, “In-Line Monitoring of Dielectric and

Fluorescence Spectroscopy During Polymer/Filler

Compounding,” in Proceedings of the Polymer

Processing Engineering 2003 Conference, July 2003,

Bradford, UK.

A.J. Bur, S.C. Roth, and M. McBrearty, “A Dielectric

Slit Die for In-Line Monitoring of Polymer Compounding,”

Review of Scientific Instruments 75, 1103–1109 (2004).

A.J. Bur, S.C. Roth, P.R. Start, and P.H. Maupin,

“Fluorescent Probes for Monitoring Microstructure of

Polymer/Clay Nanocomposites,” in Proceedings of the

Annual Technical Meeting of the Society of Plastics

Engineers, 1315–1318, May 2004, Chicago, IL.

R.D. Davis, J.W. Gilman, A.J. Bur, M. McBrearty,

P.R. Start, and Y.-H. Lee, “Dielectric Spectroscopy

During Extrusion Processing of Polyamide 6

Nanocomposites: A High Throughput Method,”

ACS Polymeric Materials: Science and Engineering,

90, 715–716, March 29, 2004, Anaheim, CA.

J.W. Gilman, S. Bourbigot, J.R. Shields, M.R. Nyden,

T. Kashiwagi, R.D. Davis, D.L. VanderHart, W. Demory,

C.A. Wilkie, A.B. Morgan, J. Harris, and R.E. Lyon,

“High Throughput Methods for Polymer Nanocomposites

Research: Extrusion, NMR Characterization and

Flammability Property Screening,” Journal of

Materials Science 38, 4451– 4460 (2003).

J.W. Gilman, P.H. Maupin, R.H. Harris, S. Bellayer,

A.J. Bur, S.C. Roth, M. Murariu, A.B. Morgan,

and J.D. Harris, “High Throughput Methods for

Nanocomposite Materials Research. Extrusion and

Visible Optical Probes,” ACS Polymeric Materials:

Science and Engineering Preprints, 90, 717–718,

March 2004, Anaheim, CA.

T. Kashiwagi, E. Grulke, J. Hilding, K. Groth,

R. Harris, K. Butler, J. Shields, S. Kharchenko, and

J. Douglas, “Thermal and Flammability Properties of

Polypropylene/Carbon Nanotube Nanocomposites,”

Polymer 45, 4227–4239 (2004).

S.B. Kharchenko, K.B. Migler, J.F. Douglas, and

J. Obrzut, “Extraordinary Flow Characteristics of

Nanotube-Filled Polymer Materials,” Nature Materials

(in press).

S.B. Kharchenko, K.B. Migler, J.F. Douglas,

J. Obrzut, and E.A. Grulke, “Rheology, Processing

and Electrical Properties of Multiwall Carbon

Nanotubes/Polypropylene Nanocomposites,” in

Proceedings of the Annual Technical Meeting of the

Society of Plastics Engineers, 1877–1881, May 2004,

Chicago, IL.

Y.H. Lee, A.J. Bur, and S.C. Roth, “ Correlation

between Degree of Exfoliation, Dielectric Properties

and Light Transmission of Nylon/Clay Nanocomposites

Probed by an Online Dielectric Slit Die,” in Proceedings

of the Annual Technical Meeting of the Society

of Plastics Engineers, 1279–1283, May 2004,

Chicago, IL.

S. Lin–Gibson, H. Kim, G. Schmidt, C.C. Han,

and E.K. Hobbie, “Shear-Induced Structure In

Polymer-Clay Nanocomposite Solutions,” Journal of

Colloid and Interface Science 274, 515–525 (2004).

S. Lin–Gibson, J.A. Pathak, E.A. Grulke, H. Wang,

and E.K. Hobbie, “Elastic Flow Instability in Nanotube

Suspensions,” Physical Review Letters 92, 048302-(1–4)

(2004).

S. Lin–Gibson, G. Schmidt, H. Kim, C.C. Han,

and E.K. Hobbie, “Shear-Induced Mesostructure in

Nanoplatelet-Polymer Networks,” Journal of Chemical

Physics 119, 8080–8083 (2003).

M.M. Malwitz, S. Lin–Gibson, E.K. Hobbie,

P.D. Butler, and G. Schmidt, “Orientation of Platelets

in Multilayered Nanocomposite Polymer Films,”

Journal of Polymer Science: Polymer Physics Edition

41, 3237–3248 (2003).

P.H. Maupin, J.W. Gilman, R.H. Harris, S. Bellayer,

A.J. Bur, S.C. Roth, M. Murariu, A.B. Morgan,

and J.D. Harris, “Optical Probes for Monitoring

Intercalation and Exfoliation in Melt Processed

Polymer Nanocomposites,” Macromolecular Rapid

Communications 25, 788–792 (2004).

D. Yebassa, S. Balakrishnan, E. Feresenbet,

D. Raghavan, P.R. Start, and S.D. Hudson, “Chemically

Functionalized Clay Vinyl Ester Nanocomposites:

Effect of Processing Parameters,” Journal of Polymer

Science Part A: Polymer Chemistry 42, 1310–1321

(2004).

Multivariant Measurement Methods

Combinatorial Methods Development

J.D. Hewes, D. Kaiser, A. Karim, and E.J. Amis,

“Combinatorial Chemistry,” in Encyclopedia of

Chemical Technology, (Kirk–Othmer Online,

Wiley Interscience, 2003).

A. Karim, A. Sehgal, J.C. Meredith, A.J. Crosby,

and E.J. Amis, “Image Analysis for High-Throughput

Materials Science,” in High Throughput Analysis —

A Tool for Combinatorial Materials Science,

edited by R.A. Potyrailo and E.J. Amis (Kluwer

Academic/Phenum Publishers, 2003), Chap. 3.
56

Polymers Division FY04 Annual Report Publication List

S.W. Kim, A. Sehgal, A. Karim, and M.J. Fasolka,

“Techniques for Combinatorial and High-Throughput

Microscopy, Part 2: Automated Optical Microscopy

Platform for Thin Film Research,” Microscopy Today

11, 30–32 (2003).

J.C. Meredith, J.L. Sormana, B.G. Keselowsky,

A.J. Garcia, A. Tona, A. Karim, and E.J. Amis,

“Combinatorial Characterization of Cell Interactions

with Polymer Surfaces,” Journal of Biomedical

Materials Research 66A, 483–490 (2003).

U.S. Schubert and E.J. Amis, “Combinatorial

and High-Throughput Approaches in Polymer and

Materials Science: Hype or Real Paradigm Shift?”

Macromolecular Rapid Communications 25, 19 (2004).

A. Sehgal, A. Karim, C.M. Stafford, and

M.J. Fasolka, “Techniques for Combinatorial and

High-Throughput Microscopy: Part 1: Gradient

Specimen Fabrication for Polymer Thin Films

Research,” Microscopy Today 11, 26 (2003).

W. Zhang, M.J. Fasolka, A. Karim, and E.J. Amis,

“An Open Source Informatics System for

Combinatorial Materials Research,” ACS Polymeric

Materials: Science and Engineering Preprints, 90,

341, March 2003, Anaheim, CA.

Adhesion and Mechanical Properties

M.Y.M. Chiang, R. Song, A.J. Crosby, W.L. Wu,

A. Karim, and E.J. Amis, “Combinatorial Approach to

the Edge Delamination Test for Thin Film Reliability —

Concept, Results and Variability,” Adhesion

Society Extended Abstracts, 44, February 2004,

Wilmington, NC.

A. Chiche and C.M. Stafford, “Peel Test Revisited

using High Throughput Methods,” Adhesion

Society Extended Abstracts, 42, February 2004,

Wilmington, NC.

A.J. Crosby, M.J. Fasolka, and K.L. Beers,

“High-throughput Craze Studies in Gradient Thin

Films using Ductile Copper Grids,” Macromolecules

(in press).

N. Eidelman, D. Raghavan, A.M. Forster,

E.J. Amis, and A. Karim, “Combinatorial Approach

to Characterizing Epoxy Curing,” Macromolecules

Rapid Communications 25, 259–263 (2004).

A.M. Forster, A. Chiche, M.Y.M. Chiang,

C.M. Stafford, and A. Karim, “Mapping Polymeric

Properties using Combinatorial and High-Throughput

Methods: Adhesion and Mechanical Properties,”

in Proceedings of the Annual Technical Meeting of

the Society of Plastics Engineers, 2004, 2374–2379,

May 2004, Chicago, IL.

A.M. Forster, C.M. Stafford, and A. Karim,

“Energy Analysis of Multi-lens Adhesion Measurements,”

ACS Polymeric Materials: Science and Engineering

Preprints, 90, 762, March 2004, Anaheim, CA.

C.M. Stafford, “Moduli of Thin Films: High

Throughput Measurement Methods,” in Adhesion

Society Extended Abstracts, February 2004,

Wilmington, NC.

C.M. Stafford, A.M. Forster, C.K. Harrison,

C.H. Davis, E.J. Amis, and A. Karim, “High-Throughput

Measurements of Polymer Adhesion and Mechanical

Properties,” ACS Polymeric Materials: Science and

Engineering Preprints, 89, 197, September 2003, NY.

C.M. Stafford, C. Harrison, K.L. Beers, A. Karim,

E.J. Amis, M.R. VanLandingham, H.C. Kim, W. Volksen,

R.D. Miller, and E.E. Simonyi, “A Buckling-based

Metrology for Measuring the Elastic Moduli of

Polymeric Thin Films,” Nature Materials 3, online

(2004).

Polymer Formulations

E.J. Amis, “Reaching beyond Discovery,” Nature

Materials 3, 83–85 (2004).

K.L. Beers, J.T. Cabral, H.J. Walls, and E.J. Amis,

“High Throughput Measurements of Polymer

Fluids for Formulations,” in Materials Research

Society Symposium Proceedings, 804, JJ7.4:1–8,

December 2003, Boston, MA.

K.L. Beers, J.T. Cabral, H.J. Walls, A. Karim, and

E.J. Amis, “A High-Throughput Milli-Fluidic Platform

For Polymer Formulations,” ACS Polymer Preprints,

44(2), 556, September 2003, New York, NY.

J.T. Cabral, S.D. Hudson, C. Harrison, and

J.F. Douglas, “Frontal Photopolymerization for

Microfluidic Applications,” Langmuir ASAP, (2004).

J.T. Cabral, S.D. Hudson, T. Wu, K.L. Beers,

J.F. Douglas, A. Karim, and E.J. Amis, “Microfluidic

Combinatorial Polymer Research,” ACS Polymeric

Materials: Science and Engineering Preprints, 90,

337–338, March 2004, Anaheim, CA.

C. Harrison, J.T. Cabral, C.M. Stafford, A. Karim,

and E.J. Amis, “A Rapid Prototyping Technique for

the Fabrication of Solvent-Resistant Structures,”

Journal of Micromechanics and Microengineering 14,

153–158 (2004).

A.I. Norman, J.T. Cabral, D.L. Ho, E.J. Amis,

and A. Karim, “Scattering Methods Applied to

High Throughput Materials Science,” ACS Polymeric

Materials: Science and Engineering, 90, 339–340,

April 2004, Anaheim, CA.
57

A.I. Norman, J.T. Cabral, A. Karim, and E.J. Amis,

“Scattering Measurements for High Throughput

Materials Science Research,” Macromolecular Rapid

Communications 25, 307–311 (2004).

M.L. Walker, A.P. Smith, and A. Karim, “A

Combinatorial Approach for Studying the Effects of

4-Biphenyl Carboxylic Acid on Polypropylene Films,”

Langmuir 19, 6582–6585 (2003).

T. Wu, Y. Mei, J.T. Cabral, C. Xu, and K.L. Beers,

“A New Synthetic Method for Controlled Polymerization

using a Microfluidic System,” Journal of the American

Chemical Society (in press).

T. Wu, Y. Mei, C. Xu, and K.L. Beers, “Phase

Transition of PDMAEMA-b-PEG in Aqueous Solution:

Dependence on Molecular Mass and Compositions,”

ACS Polymer Preprints, August 2004, Philadelphia, PA.

C. Xu, T. Wu, C.M. Drain, J.D. Batteas, and

K.L. Beers, “Synthesis of Gradient Copolymer

Brushes via Surface Initiated Atom Transfer Radical

Copolymerization,” ACS Polymer Preprints,

August 2004, Philadelphia, PA.

Scanned Probe Microscopy

M.J. Fasolka, D. Julthongpiput, E.J. Amis,

T. Nguen, and X. Gu, “Combinatorial Gradient

Reference Specimens for Advanced Scanned Probe

Microscopy Techniques,” in Proceedings Microscopy

and Microanalysis 2004, August 2004, Savannah, GA.

M.J. Fasolka, D. Julthongpiput, and K.A. Briggman,

“Gradient Reference Surfaces for Scanning Probe

Microscopy,” ACS Polymeric Materials: Science

and Engineering Preprints, 90, 721, March 2003,

Anaheim, CA.

L.S. Goldner, M.J. Fasolka, and S.N. Goldie,

“Measurement of the Local Diattenuation and

Retardance of Thin Polymer Films using Near Field

Polarimetry,” in Applications of Scanned Probe

Microscopy to Polymers, edited by J. Batteas and

G. Walker (American Chemical Society, in press).

L.S. Goldner, S.N. Goldie, M.J. Fasolka, F. Renaldo,

J.C. Hwang, and J.F. Douglas, “Near-Field Polarimetric

Characterization of Polymer Crystallites,” Applied

Physics Letters (in press).

X. Gu, T. Nguyen, M.J. Fasolka, D. Julthongpiput,

L.J. Chen, M.R. VanLandingham, Y.C. Jean, and

J.W. Martin, “Nanoscale Chemical Imaging of

Polymeric Materials with Atomic Force Microscopy,”

in Adhesion Society Extended Abstracts, February 2004,

Wilmington, NC.

D. Julthongpiput, W. Zhang, and M.J. Fasolka,

“Combinatorial and High-Throughput Microscopy for

Thin Film Research,” in Proceedings Microscopy and

Microanalysis 2004, August 2004, Savannah, GA.

T. Nguyen, X. Gu, M.J. Fasolka, K. Briggman,

J. Hwang, A. Karim, and J.W. Martin, “Mapping

Chemical Heterogeneity of Polymeric Materials

with Chemical Force Microscopy,” ACS Polymeric

Materials: Science and Engineering, 90, 141–143,

April 2004, Anaheim, CA.

Surface and Polymer Interactions

S. Granick, S.K. Kumar, E.J. Amis, M. Antonietti,

A.C. Balazs, A.K. Chakraborty, G.S. Grest, C. Hawker,

P. Janmey, E.J. Kramer, R. Nuzzo, T.P. Russell, and

C.R. Safinya, “Macromolecules at Surfaces: Research

Challenges and Opportunities from Tribology to

Biology,” Journal of Polymer Science Part B:

Polymer Physics 41, 2755–2793 (2003).

P.M. McGuiggan, “Contact Mechanics of

Dissimilar Surfaces,” in Adhesion Society Extended

Abstracts, February 2004, Wilmington, NC.

Polymers Division FY04 Annual Report Publication List
58
59

Polymers Division

Polymers Division

Chief

Eric J. Amis

Phone: 301–975–6762

E-mail: eric.amis@nist.gov

Deputy Chief

Chad R. Snyder

Phone: 301–975–4526

E-mail: chad.snyder@nist.gov

Senior Scientist

Wen-li Wu

Phone: 301–975–6839

E-mail: wen-li.wu@nist.gov

Group Leaders

Characterization and Measurement —

Method Development/Internal Capabilities

Chad R. Snyder

Standards and Data

Bruno M. Fanconi

Phone: 301–975–6769

E-mail: bruno.fanconi@nist.gov

Electronics Materials

Eric K. Lin

Phone: 301–975–6743

E-mail: eric.lin@nist.gov

Biomaterials

Newell R. Washburn

Phone: 301–975–4348

E-mail: newell.washburn@nist.gov

Processing Characterization

Kalman Migler

Phone: 301–975–4876

E-mail: kalman.migler@nist.gov

Multivariant Measurement Methods

Michael Fasolka

Phone: 301-975-8526

E-mail: michael.fasolka@nist.gov
60

Research Staff

Research Staff

Amis, Eric J.

eric.amis@nist.gov

Neutron, x-ray and light scattering

Polyelectrolytes

Viscoelastic behavior of polymers

Dendrimers and dendritic polymers

Functional biomaterials

Combinatorial methods

High-throughput experimentation

Anopchenko, Oleksiy S.+

oleksiy.anopchenko@nist.gov

Dielectric relaxation spectroscopy

X-ray scattering

Microwave spectroscopy techniques

Antonucci, Joseph M.

joseph.antonucci@nist.gov

Synthetic and polymer chemistry

Dental composites, cements and adhesion

Initiator systems

Interfacial coupling agents

Remineralizing polymer systems

Nanocomposites

Arnould, Mark

mark.arnould@nist.gov

MALDI mass spectrometry

Ashley, Karen+

karenmashley@hotmail.com

Polymer thin films

Dewetting

Combinatorial measurements

Audino, Susan A.+

susan.audino@nist.gov

Mass spectrometry

Bailey, LeeAnn O.

+

leeann.bailey@nist.gov

Cell biology

Apoptosis

Inflammatory responses

Flow cytometry

Polymerase chain reaction

Bauer, Barry J.

barry.bauer@nist.gov

Polymer synthesis

Thermal characterization

Neutron, x-ray and light scattering

Dendrimers, metallic ions nanocluster

Porous low-k thin film characterization

Carbon nanotubes

Becker, Matt

matt.becker@nist.gov

Polymer synthesis

Block copolymers

Peptide synthesis

Phage display

Combinatorial methods

Polymerase Chain Reaction

Beers, Kathryn

kathryn.beers@nist.gov

Combinatorial and high-throughput methods

Polymer formulations

Microfluidics technology

Polymer synthesis

Controlled/living polymerizations

Bencherif, Sidi+

sidi.bencherif@nist.gov

Mass spectrometry

Chemical modification

Blair, William R.

william.blair@nist.gov

Polymer analysis by size exclusion

chromatography

Mass spectrometry of polymers

High temperature viscometry

Rayleigh light scattering

Extrusion plastometry

Bowen, Rafael L.*

rafael.bowen@nist.gov

Adhesion

Dental composites

Novel monomer synthesis

Bur, Anthony J.

anthony.bur@nist.gov

Dielectric properties of polymers

Fluorescence and optical monitoring of

polymer processing

Piezoelectric, pyroelectric polymers

Viscoelastic properties of polymers

Byrd, H. Michelle

michelle.byrd@nist.gov

Mass spectrometry of polymers

Nuclear magnetic resonance (NMR)

Cabral, Joao+

joao.cabral@nist.gov

Polymeric rapid prototyping

Polymer phase separation

Millifluidic measurements
61

Research Staff

Carey, Clifton M.*

clifton.carey@nist.gov

Dental plaque

Microanalytical analysis techniques

Fluoride efficacy for dental health

De- and remineralization

Phosphate chemistry

Ion-selective electrodes

Toothpaste abrasion & erosion

Cherng, Maria*

maria.cherng@nist.gov

Calcium phosphate biomaterials

Chiang, Chwan K.

c.chiang@nist.gov

Electroluminescent polymers

Residual stress

Impedance spectroscopy

Chiang, Martin Y.

martin.chiang@nist.gov

Computational mechanics (finite element analysis)

Strength of materials, fracture mechanics

Engineering mechanics of polymer-based

materials

Bi-material interface

Image quantitation

Chiche, Arnaud+

arnaud.chiche@nist.gov

Adhesion on rough surfaces

Cavitation in peel test

Polymer adhesion

Chow, Laurence C.*

laurence.chow@nist.gov

Calcium phosphate compounds and biomaterials

Tooth demineralization and remineralization

Dental and biomedical cements

Solution chemistry

Dental caries prevention

Cicerone, Marcus T.

marcus.cicerone@nist.gov

Protein stabilization

Glass transition theory

Optical coherence microscopy

Tissue engineering scaffolds

Confocal microscopy

Spectroscopic imaging

Cipriano, Bani H.+

Polymer rheology

Cooper, James A.

james.cooper@nist.gov

Tissue engineering

Polymer scaffolds

Cell biology

Optical microscopy

Cygan, Zuzanna+

zcygan@umich.edu

Polymer formulations

Florescent probe studies

Millifluidics of polymer solutions

Combinatorial and high-throughput methods

Davis, Cher

cher.davis@nist.gov

NIST Combinatorial Methods Center (NCMC)

Polymer nanocomposites

Polymers synthesis

Combinatorial methods and measurements

DeLongchamp, Dean M.

dean.delongchamp@nist.gov

Organic electronics

Polymer thin films

Polyelectrolytes

Near-edge x-ray absorption fine structure

spectroscopy (NEXAFS)

Film electrochemistry

Dickens, Sabine*

sabine.dickens@nist.gov

Dental composites

Dental adhesives

Transmission electron microscopy

Remineralizing resin-based calcium

phosphate composites and cements

Di Marzio, Edmund A.+

edmund.dimarzio@nist.gov

Statistical mechanics of polymers

Phase transitions

Glasses

Polymers at interfaces

Douglas, Jack F.

jack.douglas@nist.gov

Theory on polymer solutions, blends, and

filled polymers

Transport properties of polymer solutions

and polymers at interfaces

Scaling and renormalization group calculation

Conductivity/viscosity of nanoparticle

filled systems

Crystallization of polymers

Dunkers, Joy P.

joy.dunkers@nist.gov

Optical coherence microscopy

Image analysis

Fiber optic spectroscopy

Infrared microspectroscopy of polymers

Confocal fluorescence microscopy

Duppins, Gretchen E.*

gretchen.duppins@nist.gov

Editorial Coordinator
62

Eichmiller, Frederick C.*

frederick.eichmiller@nist.gov

Clinical dentistry

Composites

Dentin adhesives

Polymerization shrinkage

Eidelman, Naomi B.*

naomi.eidelman@nist.gov

FTIR microspectroscopy

Characterization of dental tissues and materials

Composition of combinatorial polymer blends

Application of temperature and UV gradients

to polymers

Fanconi, Bruno M.

bruno.fanconi@nist.gov

Infrared & Raman spectroscopy of polymers

Structure of polymers

Polymer fracture

Process monitoring of polymer composites

Fasolka, Michael J.

mfasolka@nist.gov

Combinatorial and high-throughput methods

NIST Combinatorial Methods Center (NCMC)

Self-assembled structures

Surface energy patterning and control

Surfaces and interfaces

Scanning probe microscopy

Flaim, Glenn M.*

glenn.flaim@nist.gov

Fabricating dental composites

Floyd, Cynthia J. E.*

cynthia.floyd@nist.gov

Dental composites

Nuclear magnetic resonance (NMR)

Flynn, Kathleen M.

kathleen.flynn@nist.gov

Melt flow rate measurements

Size exclusion chromatography

Mass spectrometry of polymers

Forster, Aaron M.

aaron.forster@nist.gov

Combinatorial methods and measurements

Polymer adhesion

Polymer interfaces

Biopolymer interactions

Fowler, Bruce O.+

bruce.fowler@nist.gov

Infrared and Raman spectroscopy

Structure of calcium phosphates, bones,

and teeth

Composites

Frukhtbeyn, Stanislav*

stan.frukhtbeyn@nist.gov

Calcium phosphate compounds and biomaterials

Topical dental fluorides

Fry, Dan J.

dan.fry@nist.gov

Particle alignment and dispersion

Carbon nanotubes

Rheology

Galvin, Agnes Ly.*

agnes.galvin@nist.gov

Clinical dental assistant

Adhesion measurements

George, Laurie A.*

laurie.george@nist.gov

Network Administrator

Giuseppetti, Anthony A.*

anthony.giuseppetti@nist.gov

Casting of dental alloys

Scanning electron microcopy

Dental materials testing

Guttman, Charles M.

charles.guttman@nist.gov

Solution properties of polymers

Size exclusion chromatography

Mass spectrometry of polymers

Han, Charles C.+

charles.han@nist.gov

Phase behavior of polymer blends

Phase separation kinetics of polymer blends

Polymer characterization and diffusion

Shear mixing/demixing and morphology control

of polymer blends

Static, time resolved, and quasi-elastic scattering

Hobbie, Erik K.

erik.hobbie@nist.gov

Light scattering and optical microscopy

Dynamics of complex fluids

Shear-induced structures in polymer blends

and solutions

Hodkinson, Christine S.*

christine.hodkinson@nist.gov

Manager, Administrative Services

Holmes, Gale A.

gale.homes@nist.gov

Composite interface science

Chemical-structure–mechanical property

relationships for:

Polymer chemistry

Mass spectroscopy

Nanocomposites

Ballistic resistance

Research Staff
63

Hu, Tengjiao+

tengjiao.hu@nist.gov

Neutron, x-ray, and light scattering

Conformation of polymer chains in solution and

at interfaces

Imperfections in crystals

Hudson, Steven D.

steven.hudson@nist.gov

Electron microscopy

Polymeric surfactant and interfacial dynamics

Self-assembly

Nanoparticle characterization and assembly

Biomaterials

Hussain, Latiff*

latiff.hussain@nist.gov

Synthetic organic/polymer chemistry of

monomers

Dental composites and cements

Dental adhesives

Initiator systems

Remineralizing polymer systems

Biomaterials

Jablonski, Erin L.

erin.jablonski@nist.gov

Near-edge x-ray absorption fine structure

spectroscopy (NEXAFS)

Polymer diffusion, surfaces, thin films

Polymer phase behavior

Jones, Ronald L.

ronald.jones@nist.gov

Neutron and x-ray scattering

Nanoimprint lithography

Neutron reflectivity

Polymer surfaces and thin films

Polymer phase transitions and computer

simulation

Julthongpiput, Duangrut+

duangrut@hotmail.com

Combinatorial methods and measurements

Polymer adhesion and mechanical properties

Scanning probe microscopy

Kano, Kenji+

kkano@nist.gov

Dielectric relaxation of polymers

Nonlinear dielectric and conductive spectroscopy

Organic electronics

Karim, Alamgir

alamgir.karim@nist.gov

Combinatorial and high-throughput methods

Patterning of thin-polymer blend films on

inhomogenous surfaces

Neutron & x-ray reflection and scattering

AFM and optical microscopy

Nanofilled polymer films

Nanostructured materials

Metrology for nanoscale manufacturing

Research Staff

Kee, Tak+

tak.kee@nist.gov

Ultrafast spectroscopy

Coherent anti-Stokes Raman scattering (CARS)

microscopy

Tissue engineering scaffolds

Confocal microscopy

Kharchenko, Semen+

semen.kharchenko@nist.gov

Stress optical properties

Birefringence

Viscoelastic properties

Khatri, Chetan A.+

chetan.khatri@nist.gov

Monomer/polymer synthesis and characterization

Khoury, Freddy A.

freddy.khoury@nist.gov

Crystallization, structure and morphology

of polymers

Analytical electron microscopy of polymers

Wide-angle and small-angle x-ray diffraction

Structure and mechanical property relationships

Kim, Jae Hyun+

jaehyun@nist.gov

Fiber/matrix interface

Mechanical properties

Polymer composites

Optical coherence microscopy

Landis, Forrest A.

forrest.landis@nist.gov

Crystallization and melting of miscible polymer

blends

Ionomers

Optical coherence microscopy

Tissue engineered scaffolds

Static small-angle laser light scattering

Lee, Hae-Jeong+

hae-jeong.lee@nist.gov

X-ray reflectivity

Small-angle neutron scattering

Structural characterization of low dielectric

constant thin films

Porosimetry of porous thin films

Lee, Yu-Hsin (Mandy)+

yu-hsin.lee@nist.gov

Dielectric relaxation spectroscopy

Nanocomposites

Atomic force microscopy

Rubber-toughened phenolic resins

Dynamic mechanical analysis of polymer blends

Liao, Nam S.+

nam.liao@nist.gov

Web page development
64

Lin, Eric K.

eric.lin@nist.gov

Polymer thin films and interfaces

Polymeric photoresists for lithography

Small angle neutron scattering

Statistical mechanics

X-ray and neutron reflectivity

Lin, Nancy J.

nancy.lin@nist.gov

Combinatorial screening of scaffolds

Cellular response to materials

Lin-Gibson, Sheng

sheng.lin-gibson@nist.gov

Rheology of gels & nanocomposites

Mass spectrometry of synthetic polymers

Polymer synthesis and modification

Structure and dynamics of nanocomposite

polymeric materials

Tissue engineering hydrogels

Liu, Da-Wei

da-wei.liu@nist.gov

Polymer synthesis

Thermal gravimetric analysis

Differential scanning calorimetry

Gel permeation chromatography

Infrared spectroscopy

Nuclear magnetic resonance (NMR)

Markovic, Milenko*

milenko.markovic@nist.gov

Calcium phosphate chemistry

Biomineralization (normal and pathological)

Crystal growth and dissolution kinetics

Heterogeneous equilibria

Maurey, John R.+

john.maurey@nist.gov

Ultracentrifugation

Rayleigh light scattering

Osmometry

Densimetry

Refractometry

Intrinsic viscosity

McDonough, Walter G.

walter.mcdonough@nist.gov

Processing and cure monitoring polymer

composites

Failure and fracture of polymers

Polymer composite interfaces

Dental materials

McGuiggan, Patricia

patricia.mcguiggan@nist.gov

Atomic force microscopy

Viscoelastic properties

Surface force measurements

Mei, Ying+

ying.mei@nist.gov

Polymer synthesis

Peptide synthesis

Biodegradable polymers

Biomimetic polymers

Migler, Kalman

kalman.migler@nist.gov

Effects of shear and pressure on phase behavior

Fluorescence and optical monitoring of

polymer processing

Liquid crystals

Shear-induced two phase structures

Polymer slippage

Moon, Seung-ho+

seung-ho.moon@nist.gov

Combinatorial and high-throughput

measurements

Adhesive properties

Pressure sensitive adhesives

Scanning probe microscopy

Norman, Alexander+

alexander.norman@nist.gov

Polymer formulations

Water soluble polymers

Microemulsions

Neutron and x-ray scattering from polymers

Obrzut, Jan

jan.obrzut@nist.gov

Dielectric relaxation spectroscopy

Electronic properties of polymers and composites

Electronic packaging

Microwave and optical waveguides

Photoelectron spectroscopy (x-ray and UV)

Reliability, stress testing

Parry, Edward E.*

edward.parry@nist.gov

Dental appliance and crown and bridges

fabrication

Machine shop applications

Pathak, Jai A.+

jai.pathak@nist.gov

Rheology and linear viscoelasticity

Polymer dynamics and complex fluids

Microfluidics

Phelan, Jr., Frederick R.

frederick.phelan@nist.gov

Resin transfer molding: modeling and

processing studies

Viscoelastic flow modeling

Flow in porous media

Lattice Boltzmann methods

Research Staff
65

Prabhu, Vivek M.

vmprabhu@nist.gov

Small-angle neutron scattering

Polyelectrolytes

Polymers for lithography

Fluorescence correlation spectroscopy

Polymer thin films

X-ray and neutron reflectivity

Quinn, Janet*

janet.quinn@nist.gov

Fractography

Dental materials and material properties

Composites

Richards, Nicola*

nicola.richards@nist.gov

Dental restorative materials

Polymer matrix composites

Roth, Steven C.

steven.roth@nist.gov

Piezoelectric polymer transducers — fabrication

and applications

Vacuum deposition of metals

Calibration of polymer transducers

Microcomputer interfacing

Fluorescence measurements

Schumacher, Gary E.*

gary.schumacher@nist.gov

Clinical dentistry

Composites

Dentin adhesives

Simon, Carl G., Jr.

carl.simon@nist.gov

Biocompatibility

Cytotoxicity

Signaling in human platelets

Bone marrow cell lineage/trafficking

Combinatorial methods

Skrtic, Drago*

drago.skrtic@nist.gov

Bioactive amorphous calcium phosphate-based

dental materials

Snyder, Chad R.

chad.snyder@nist.gov

Polymer crystallization

WAXD and SAXS of polymeric materials

Thermal expansion measurements

Thermal analysis

Dielectric measurements and behavior

Ballistic resistance

Sohn, Daewon+

daewon.sohn@nist.gov

Self-assembled monolayers

Dynamic and static light scattering

Polymer diffusion

Nanoparticles

Polymer surfactants

Soles, Christopher L.

csoles@nist.gov

Polymer dynamics

Inelastic neutron scattering

Low-k dielectric thin films

X-ray and neutron reflectivity

Polymer thin films and lithography

Ion beam scattering

Nanoimprint lithography

Stafford, Christopher

chris.stafford@nist.gov

Combinatorial and high-throughput methods

Polymer thin films

Polymer adhesion

Mechanical properties of thin films

Surfaces and interfaces

Start, Paul R.+

paul.start@nist.gov

Nanocomposites

Transmission electron microscopy

Sol-gel processes

Surfactants and interfacial tension

Stephens, Jean S.

jean.stephens@nist.gov

Optical coherence microscopy

Cell/scaffold interactions

Tissue engineering

Electrospinning

Fiber morphology

Stone, Phillip A.+

philip.a.stone@nist.gov

Microfluidic devices

Dynamics of carbon nanotubes

Rheology

Taboas, Juan M.+

juan.taboas@nist.gov

Biomedical engineering

Cell and tissue mechanics

Mechanoactive bioreactors

Tissue engineering

Research Staff
66

Takagi, Shozo*

shozo.takagi@nist.gov

Crystallography

X-ray diffraction

Calcium phosphate biomaterials

Topical fluoridation

De- and remineralization

Tesk, John A.

john.tesk@nist.gov

Biomaterials: industrial relations

Characterization: biomaterials; physical and

mechanical properties

Reference biomaterials

Reference data for biomaterials

Biomaterials: orthopaedics, cardiovascular,

dental, opthalmic, & tissue-engineered

medical devices

Standards for medical devices

Tung, Ming S.*

ming.tung@nist.gov

Chemistry of calcium phosphate and

peroxide compounds

Remineralization studies

Standard reference materials

Vakili, Zohreh+

zohreh.vakili@nist.gov

Mass spectrometry

Van Workum, Kevin

kevin.vanworkum@nist.gov

Monte Carlo and molecular dynamics

simulations

Mechanical properties of glassy and

crystalline structures

Dispersion in nanocomposites

VanderHart, David L.

david.vanderhart@nist.gov

Measurement of orientation in polymer fibers

and films

Solid-state NMR of polymers

Measurement of polymer morphology at the

2–50 nm scale

Pulsed field gradient NMR

Vogel, Brandon M.+

brandon.vogel@nist.gov

Polymer synthesis combinatorial methods

Drug delivery

Vogel, Gerald L.*

gerald.vogel@nist.gov

Dental plaque chemistry

Chemistry of calcium phosphates

Microanalytical techniques

Fluoride chemistry

Vogt, Bryan D.

bryan.vogt@nist.gov

Polymer thin film properties

X-ray and neutron reflectivity

Interfacial effects

Quartz crystal microbalance

Ordered mesoporous materials

Conducting polymers

Wallace, William E.

william.wallace@nist.gov

Mass spectrometry

Geometric data analysis methods

Walls, Howard J.

howard.walls@nist.gov

Rheology of polymers

Combinatorial measurements and methods

Viscoelastic polymers

Wang, Chia-Ying+

cywang@nist.gov

Small-angle x-ray scattering

Polymer diffusion

Microphase transitions of block copolymers

Fluorescence spectroscopy of polymers

Wang, Francis W.

francis.wang@nist.gov

Photophysics and photochemistry of polymers

Fluorescence spectroscopy

Cure monitoring of polymerization

Tissue engineering

Wang, Michael X.+

mwang@nist.gov

Small angle x-ray & neutron scattering

X-ray and neutron reflectivity

Light scattering

Polymer thin films

Combinatorial methods

Wang, Xianfeng+

xianfeng.wang@nist.gov

Monte Carlo simulations

Finite element modeling

Polymer composites

Mechanical properties

Image quantitation

Washburn, Newell

newell.washburn@nist.gov

Tissue engineering

Polymer blends

Biomaterial interfaces

Viscoelastic properties of polymers

Research Staff
67

Weir, Michael

michael.weir@nist.gov

Biomaterials

Tissue engineering

Degradable hydrogels

Growth factor dynamics and cellular response

in biomaterials

Wetzel, Stephanie J.

stephanie.wetzel@nist.gov

Mass spectrometry of polymers

Chemometrics

Size exclusion chromatography

Wilder, Elizabeth A.

elizabeth.wilder@nist.gov

Rheological behavior of polymer gels

Mechanical properties of polymer composites

Structure-property relationships

Wilson, Kristin S.

kristen.wilson@nist.gov

Dental nanocomposite materials

Mechanical properties

Wu, Wen-li

wen-li.wu@nist.gov

Neutron and x-ray scattering and reflectivity

Electron microscopy

Mechanical behavior of polymers and composites

Polymer surfaces and interfaces

Polymer networks

Wu, Tao+

tao.wu@nist.gov

Polymer formulations

Polymer synthesis

Interfacial tension measurements

Combinatorial and high-throughput methods

Research Staff

Xu, Chang

chang.xu@nist.gov

Combinatorial and high-throughput methods

Polymer formulations

Surface polymerization

Xu, Hockin*

hockin.xu@nist.gov

Bone tissue engineering

Scaffold and cell interactions

Fiber and whisker composites

Zhang, Kai+

kai.zhang@nist.gov

Polymer scaffolds

Tissue engineering

Dental resins

Combinatorial methods

Zhang, Wenhua+

wezhang@nist.gov

Combinatorial and high-throughput informatics

Database structure

Laboratory automation

Polymer thin films and blends

* Research Associate

+ Guest Scientist
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69

Organizational Charts

Organizational Charts

Materials Science and Engineering Laboratory

Polymers

E.J. Amis, Chief

C.R. Snyder, Deputy

Metallurgy

C.A. Handwerker, Chief

F.W. Gayle, Deputy

Ceramics

D.L. Kaiser, Chief

R.G. Munro, Deputy

Materials Reliability

A.F. Clark, Chief

T.A. Siewert, Deputy

NIST Center for

Neutron Research

P.D. Gallagher, Director

Director

Deputy Director

National Institute of Standards and Technology

Director

Boulder Laboratories

Baldrige National Quality

Program

Director for

Administration

& Chief Financial

Officer

Technology

Services

Advanced

Technology

Program

Manufacturing

Extension

Partnership

Manufacturing

Engineering

Laboratory

Chemical Science

and Technology

Laboratory

Materials Science

and Engineering

Laboratory

Electronics and

Electrical Engineering

Laboratory

Information

Technology

Laboratory

Physics

Laboratory

Building and

Fire Research

Laboratory

L.E. Smith, Director

S.W. Freiman, Deputy Director
70

Eric J. Amis, Chief

Chad R. Snyder, Deputy Chief

Wen-li Wu, Senior Scientist

Dawn Bradley, Administrative Officer

Austin Gross, Division Secretary

Lisa Fedders, Administrative Assistant

Polymers Division (854.00)

Characterization and Measurement

(854.01)

Chad R. Snyder, Leader

Bronny Webb, Secretary

Organizational Charts

A. Bur

D. Fry

E. Hobbie

S. Hudson

F. Phelan

S. Roth

B. Cipriano

S. Kharchenko

M. Meillon

J. Pathak

P. Start

P. Stone

J. Taboas

K. Beers

Z. Cygan

C. Davis

A. Forster

A. Karim

C. Stafford

H. Walls

K. Ashley

J. Cabral

A. Chiche

D. Julthongpiput

S. Moon

A. Norman

D. Sohn

T. Wu

C. Xu

W. Zhang

Processing

Characterization (854.05)

Kalman Migler, Leader

Lisa Long, Secretary

Multivariant Measurement

Methods (854.06)

Michael Fasolka, Acting Leader

Lisa Long, Secretary

J. Antonucci

M. Becker

M. Cicerone

J. Cooper

S. Lin–Gibson

C. Simon

F. Wang

E. Wilder

K. Wilson

L. Bailey

S. Bencherif

C. Khatri

N. Lin

Y. Mei

B. Vogel

K. Zhang

Biomaterials

(854.03)

Newell Washburn, Leader

Lisa Long, Secretary

O. Anopchenko

K. Kano

H. Lee

S. Sambasivan

C. Chiang

D. DeLongchamp

E. Jablonski

R. Jones

J. Obrzut

V. Prabhu

C. Soles

B. Vogt

M. Arnould

W. Blair

M. Byrd

K. Flynn

C. Guttman

J. Tesk

W. Wallace

S. Wetzel

Electronics Materials

(854.02)

Eric Lin, Leader

Bronny Webb, Secretary

Standards and Data

Bruno Fanconi, Leader

B. Bauer

M. Chiang

J. Douglas

J. Dunkers

G. Holmes

F. Khoury

F. Landis

D. Liu

W. McDonough

P. McGuiggan

J. Stephens

K. Van Workum

D. VanderHart

Method Development/

Internal Capabilities

Chad R. Snyder, Leader

S. Audino

J. Maurey

Z. Vakili

T. Kee

J. Kim

S. Liao

X. Wang
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72