i

National Institute of

Standards and Technology

James Turner

Acting Director

U.S. Department 

of Commerce

Carlos M. Gutierrez

Secretary

Materials Science and

Engineering Laboratory

FY 2006 

Programs and 

Accomplishments

Polymers 

Division

Eric J. Amis, Chief

Chad R. Snyder, Deputy Chief

NISTIR 7480

February 2008
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

Cell Morphology and Migration Linked to Substrate Rigidity ...........................................2

Chemical Heterogeneity in Chemically Amplified Photoresists: 

FTIR Measurements and the Effect on Film Dissolution ...................................................4

Combinatorial Platform for Measuring the Effect of 

Substrate Heterogeneities....................................................................................................6

Comparative Metrologies for Evaluating Single Wall Carbon

Nanotube (SWNT) Dispersion ............................................................................................8

Numerical Optimization of Complex Instrumentation......................................................10

Platform for Characterizing Defects in Magnetic Nanoparticles......................................12

Advanced Manufacturing Processes........................................................................................15

NIST Combinatorial Methods Center:

 A Pioneer and Partner in Accelerated Materials Research........................................16

Polymer Formations:

 Soft Materials Measurements on a Chip.....................................................................17

Quantitative Polymer Mass Spectrometry ........................................................................18

Biomaterials.............................................................................................................................19

3D Tissue Scaffolds...........................................................................................................20

Combinatorial Methods for Tissue Engineering ...............................................................21

Dental Polymers and Composites:

 Developing a Test Suite for Total Materials Characterization ...................................22

Metrology for Biomechanical Effects on Cell/Material Interactions................................23

Materials for Electronics..........................................................................................................25

Dimensional Metrology with Small Angle X-Ray Scattering...........................................26

Organic Electronics...........................................................................................................27

Polymer Photoresists for Next-Generation Nanolithography ...........................................28
iv

Table of Contents

Nanometrology .......................................................................................................................29

Carbon Nanotube Materials:

Achieving the Gold Standard in Quality and Characterization ........................................30

Combinatorial Methods for Nanomaterials and Nanometrology......................................31

Defects in Nanostructured Materials.................................................................................32

Mechanics of Complex Interfaces:

 Libraries for Probing Interfacial Adhesion ................................................................33

Nanoimprint Lithography..................................................................................................34

Self-Assembly for Soft Nanomanufacturing.....................................................................35

Safety and Reliability...............................................................................................................37

Ballistic Resistance of Polymeric Materials......................................................................38

Polymers Division FY06 Annual Report Publication List.......................................................39

Polymers Division....................................................................................................................49

Research Staff..........................................................................................................................50

Organizational Charts ..............................................................................................................59
1

Executive Summary

I am pleased to yet again report to you the results of 

a strong year for the Polymers Division. Our staff and 

research collaborators continue to be acknowledged 

for their work in important areas, and in my summary 

this year, I would like to note some of the recognitions 

received this year.

As an agency of the Department of Commerce, the 

National Institute of Standards and Technology focuses 

on work, often in collaboration with industry, to foster 

innovation, trade, security, and jobs. This year, our 

efforts have been recognized by an award specifically 

related to service to industry. The Secretary of Commerce awarded the Department of Commerce Silver 

Medal for the development of innovative measurement 

methods for the structure and properties of nanoporous 

low-k thin films needed in next-generation IC’s to Barry 

J. Bauer, Christopher L. Soles, Da-Wei Liu, Ronald L. 

Jones, Eric K. Lin, and Wen-li Wu. Silver Medals are 

awarded for work that demonstrates exceptional performance characterized by superlative contributions that 

have a direct and lasting impact within the Department 

of Commerce. 

Two Bronze Medals were also awarded within the 

Division by the NIST Director. Jan Obrzut received his 

for leadership in development and demonstration of an 

accurate broadband dielectric measurement for frequencies where earlier methods were inadequate; and 

Christopher L. Soles received his for innovative applications of incoherent neutron scattering to measure 

the dynamics of glassy materials. Bronze Medals are 

awarded for outstanding contributions that increase the 

efficiency and effectiveness of NIST.

Complementing these awards for service to industry, 

several scientists and engineers were acknowledged for 

their outstanding scientific careers. In a White House 

ceremony on July 26, 2006, Christopher L. Soles was 

awarded the 2005 Presidential Early Career Award 

for Scientists and Engineers (PECASE), the nation’s 

highest honor for professionals at the outset of their 

independent research careers. Chris was recognized for 

his development of measurement methods and scientific 

insight into confined nanostructured materials. Annually, two NIST researchers are nominated for PECASE. 

Chris is the fourth Polymers Division scientist to win 

this honor with the previous awardees Sharon Glotzer 

(1998), Eric Lin (2001), and Michael Fasolka (2004).

At the 2006 Annual March meeting of the American 

Physical Society (APS), Steven D. Hudson was named 

a Fellow of the Society for excellence in structural studies of supramolecular and polymeric materials and the 

quantative description of droplet and particle dispersion 

under quiescent and flow conditions. Steve joins seven 

other current Polymers Division scientists and dozens of 

Division alumni as APS fellows.

Annually, our report provides a sample of the outstanding research from the Polymers Division. 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.

This also represents my last report to you as Chief 

of the Polymers Division. With the start of the 2007 

fiscal year, I moved to our laboratory office as Deputy 

Director of Materials Science and Engineering. I have 

thoroughly enjoyed my 11 years working with the outstanding team of talented and dedicated scientists in this 

premier organization. Our research continues to push 

the scientific boundaries and fulfill the NIST mission. 

It is with heartfelt appreciation that I thank the staff of 

the Division and our many alumni for their support as 

we have grown and learned together. I am especially 

grateful to the members of my management team, Chad 

Snyder, Eric Lin, Alamgir Karim, Kalman Migler, Mike 

Fasolka, Marc Cicerone, and Dawn Bradley, for their 

dedication, willingness to challenge the status quo, and 

respect they show to our goals. The same can be said for 

the many great individuals who make up the Division 

staff, our collaborators, and the NIST management. I 

know this team will continue to grow as they give their 

support to Eric Lin as the new Division Chief. Together 

we will continue the tradition of excellence of the NIST 

Polymers Division.

Eric J. Amis 

 Chief, Polymers Division

Executive Summary

Polymers Division Management Team. Clockwise from Left: 

Kalman Migler, Eric Lin, Chad Snyder, Eric Amis, 

Alamgir Karim, Mike Fasolka, and Marc Cicerone.
2

Cell Morphology and Migration Linked to Substrate Rigidity

Appropriate cell migration is critical to many areas 

of biology, and to guiding outcomes in Tissue Engineering. Also, cell morphological changes affect the 

formation of cell adhesion and phenotypic expression. Cells have been shown to change morphology 

and migrate in response to a wide number of external 

stimuli, including chemical, mechanical, and electrical. We have developed a model that links cell 

morphology and migration to substrate mechanical 

properties.

Martin Y.M. Chiang 

Cells cultured, in vivo, on substrates show activity 

that is influenced by substrate mechanics in the following ways: 

(1) Cells respond to variation in substrate rigidity. Certain types of cells on stiffer substrates have less rounded 

morphologies and are more likely to extend into branched 

morphologies than the same cells on softer substrates (Fig. 

1a). In contrast, some experimental studies show that other 

cell types extend into more branches on softer substrates and 

exhibit no preference to branching on stiffer ones (Fig. 1b). 

Figure 1: Morphological change (stability).

(2) When cells, cultured on a substrate, are subjected 

to a uniaxial cyclical substrate stretch, the cells tend to 

elongate perpendicular to the direction of stretch 

 (Fig. 2). 

(3) Cells tend to migrate towards stiffer regions on 

a substrate with a stiffness gradient, which is known as 

durotaxis, although reverse durotaxis (migration towards 

less stiff regions) has also been observed.

Guided by the aforementioned experimental observations, we have developed a mathematical model of cellsubstrate adhesion that connects cell morphology and 

migration with the mechanical properties of the extracellular environment. The model is based on the hypothesis that morphology of a cell adhering to a substrate is 

driven by the competition between strain energies (in 

the cell and substrate) and interfacial energy (work of 

adhesion at the cell periphery). The stability of a given 

cell morphology is given by the total energy of the cell/

substrate system based on strain and interfacial energies.

The total free energy (Etot) is expressed as the sum 

of the strain energy in the cell and substrate (E1

) and 

interfacial energy at the cell periphery (E2

). The ratio of 

these energies is given the designation b:

b = E1

/E2

In Fig. 3, the graph on the right hand side of the figure displays Etot as a function of perturbation mode for 

several values of b. Here, b is varied by changing substrate rigidity. The image insets correspond to the most 

Figure 3: Left-An initially circular cell (solid line) undergoing 

a morphological perturbation of harmonic form (dotted line). 

Right-The energy variation as a function of perturbation mode (or 

number of lobes) n for different values of b due to changes of the 

substrate rigidity.

Figure 2: Orientation stability.

Technical Highlights
3

stable configuration of the cell predicted using phasefield simulation that includes geometric nonlinearity.

In agreement with experimental observations reported in the literature, our model has demonstrated the hypotheses that the morphological stability of an adherent 

cell to substrate is governed by the minimal total free 

energy in the cell/substrate system. The morphological 

changes of a cell can be rationalized as the consequence 

of competition between interfacial and elastic energies 

in the total free energy of cell/substrate system. Thus, 

the cell changes into its energetically favorable shape 

by the assembling/disassembling of focal adhesions 

distributed around the cell periphery. The interfacial 

energy between the cell and substrate stabilizes the cell 

morphology while the strain energy from intracellular 

and extracellular forces destabilizes it. The competition 

results in a “resonant” window that refers to the range 

of the stiffness ratio (ms

/mc, substrate to cell) over which 

the cell is in interaction with the substrate (Fig. 4). With 

this interaction, the cell and substrate can be mutually 

compliant. Consequently, it becomes energetically favorable for the cell to undergo significant morphological 

changes. More importantly, the results from our analysis indicates that the change of trend in morphological 

stability (the inflection point, Fig. 5) corresponds to 

ms

 = mc. Therefore, controlled experiments can be planed 

to estimate the cell stiffness by observing this change (as 

shown in Fig. 4.) 

to explore cell morphology and migration in a more 

complex native environment subjected to other external 

stimuli.

Within the framework of our phase-field model, cell 

migration and orientation are due to the variation of substrate stiffness and durotaxis is viewed as a progressive

minimization of the total free energy in a cell/substrate 

system. Our analysis indicates that the cell migrates not 

only from softer towards to stiffer regions of the substrate, but that the reverse is possible under certain conditions. The occurrence of durotaxis or reverse durotaxis 

phenomena depends on the relative rigidity between the 

cell and substrate. 

Our study provides insights into the dependence of 

cell morphology and migration on substrate mechanics; 

it can be used to rationalize discrepancies on the trend 

of morphological changes reported in the literature as 

well as cell locomotion due to the stiffness variation of a 

substrate. Finally, the study provides a guide in measurement science for cell stiffness and can be extended 

Figure 5: The variation of normalized b as a function of rigidity 

ratio, ms

/mc, for various interfacial energies, g1 and g2 (g1 > g2), 

corresponding to different cell/substrate systems. b, the ratio of 

the interfacial energy density to strain energy density of the cell/

substrate system. The decrease of b gives rise to morphological 

instabilities.

For More Information on This Topic

M.Y.M. Chiang, J.P. Dunkers, and M.T. Cicerone 

(Polymers Division, NIST)

Figure 4: Schematic representing how cell morphology changes 

in response to substrate rigidity.

Technical Highlights

Figure 6: A typical evolution path of the cell from the initial 

stage to final stage of the simulation. A circular cell initially 

located on the softer region of substrate with a stiffness gradient 

(a). The cell migrates from the substrate surface with lower stiffness to higher stiffness (b-f). When the cell migrates to a region 

on the substrate surface with a critical stiffness, the cell morphology becomes unstable and changes from the original shape 

to a “potato”-like shape (f). This phenomenon is attributed to a 

consequence of the competition between energies for the morphological change and the migration.
4

Chemical Heterogeneity in Chemically Amplified Photoresists: 

FTIR Measurements and the Effect on Film Dissolution

sites are randomly distributed. If the measured fraction exceeds this limit, dimer clusters are expected and 

the positive deviation from the homogeneous limit is 

indicative of the degree of heterogeneity. These results 

can help understand correlations between compositional 

heterogeneity and the roughness observed upon the dissolution (development) of resists in aqueous bases. 

Figure 1a shows the IR spectrum of methacrylic acid 

(MAA) in a partially deprotected poly(methyladamantyl 

methacrylate) (PMAdMA) film with different extents 

of reaction. If we define a ratio of the hydrogen bonded 

C=O to the total C=O in MAA, Fbond, we can obtain a 

continuous change of this ratio with the extent of reaction of the film (Figure 1b). Here, Fbond is calculated 

from the area under the IR peaks corresponding to hydrogen bonded and free C=O, respectively. The degree 

of heterogeneity within the film is defined relative to the 

ideal homogeneous structure with a random distribution 

of components.

Figure 2: Degree of heterogeneity vs. deperotection level in 

PMAdMA film for photoacid concentration C =0.006 nm-3

Technical Highlights

The semiconductor industry roadmap indicates that 

excessive line-edge roughness (LER) in photoresists 

at sub 45 nm half pitch is a critical problem with no 

known manufacturable solutions. It has been broadly 

accepted that the chemically heterogeneous structure 

in the photoresist is due to the reaction-diffusion 

process used to alter the solubility of exposed areas 

of the material. However, few measurements of this 

structure have been successful. In this work, we demonstrate that Fourier-Transfer Infrared (FTIR) spectroscopy measurements can be used to parameterize 

the degree of heterogeneity in polymer thin films, and 

to illustrate its effect on the response of the polymer 

to an aqueous base developer solution. 

Vivek M. Prabhu 

T he semiconductor industry roadmap indicates that excessive line-edge roughness (LER) in photoresists at sub 45 nm half pitch is a critical problem with 

no known manufacturable solutions. LER is believed to 

result from the heterogeneous distribution in the deprotection product at the line edge of the latent image. The 

optical image quality of the exposure and the distribution of the subsequently generated photoacid catalysts 

is a key factor to LER. This heterogeneous deprotection distribution results in local differences in solubility 

in the developer solution, where highly deprotected 

chains dissolve, and those with insufficient deprotection 

remains in the film. A quantitative measure of the degree of heterogeneity in the deprotection reaction product is needed to identify and enable design strategies to 

reduce materials sources of LER. Direct experimental 

observation of the degree of heterogeneity is difficult 

because of the small size scale, and the limited contrast 

between protected and deprotected chains. 

Here, we developed a method to characterize the degree of heterogeneity in thin polymer films using FTIR 

on materials that exhibit hydrogen bonding. Carboxyl 

groups are well known to form dimers that induce a 

band shift in C=O IR spectra relative to the monomer 

state. Since hydrogen bonding (dimer) can only occur 

with adjacent C=O groups, and the films are processed 

well below the glass transition, the local distribution in 

chemical composition generated by deprotection reaction can be deduced from the ratio of hydrogen bonded 

to free C=O groups. As a reference point, we use the 

fraction of hydrogen-bonded C=O groups when the 

Figure 1: (a) Evolution of C=O stretching bands of MAA groups 

with reaction extent in PMAdMA samples. (b) Change of fraction 

of hydrogen bonded C=O in MAA groups with deprotection reaction extent.
5

We calculate the degree of heterogeneity (DH) and 

the dependence of DH on deprotection level as shown 

in Fig. 2. It can be seen that the DH is small at very low 

and very high deprotection level, but is maximized at a 

deprotection level of approximately 0.20 to 0.25. These 

trends arise because the system heterogeneity is dominated by one component at low or high deprotection 

levels, and the contrast from the uniform phase is small.

The heterogeneity measured from FTIR strongly 

affects the response of a thin film to an aqueous base 

solution as a function of the average composition of the 

polymer as it changes during an acid catalyzed deprotection reaction.

to the solution. With longer reaction time, diffusion 

and reaction of the photoacid molecules increases the 

methacrylic acid content, which eventually forms a connected or percolated network. The percolated character 

of these groups provides pathways for solute transport 

throughout the film, enabling the hydroxide ions to induce film swelling by titrating methacrylic acid groups. 

The film swelling is enabled by the percolated distribution of deprotection domains, while the degree of swelling is controlled by the ionizable group content. 

These data raise an interesting question about the 

origin of the stability of the swollen films. For most 

polymer gels, film stability during swelling is due to the 

existence of cross-link junctions formed covalently or 

by physical entanglement of high molar mass chains. 

However, the system here does not have any chemical 

cross linking, and the molar mass of the polymers is 

below the entanglement molar mass. The stability of 

our swollen films is attributed to physico-chemical junctions formed by the continuum of hydrophobic (methyladamantyl) groups. The formation of these junctions 

is analogous to the aggregation of hydrophobic/hydrophilic copolymers in aqueous solution. 

The combination of FTIR and QCM measurements 

provides new insights into the mechanisms of development which are being incorporated into photoresist 

models of latent-image formation and dissolution. In 

future work, we plan to extend these results to the gradient latent image line-edge to understand the polyelectrolyte effects at the liquid-photoresist interface by in situ

neutron reflectivity.

For More Information on This Topic

B.D. Vogt, S. Kang, V.M. Prabhu, E.K. Lin, S.K. Satija, 

K. Turnquest, and W. Wu, Macromolecules 39, 8311 

(2006).

A. Rao, S. Kang , B. D. Vogt , V. M. Prabhu, E. K. Lin, 

W. L. Wu, M. Muthukumar, W. D. Hinsberg, Langmuir

22, 10009 (2006).

Figure 3: Polyelectrolyte quasi-equilibrium phase behavior 

determined from the long-time QCM response in frequency (ΔF) 

and dissipation (ΔD).

Figure 4: Schematic of the deprotection morphologies of the four 

regimes and relationship to the average fMAA (and fMADMA ) and 

percolation threshold (rc ).

Technical Highlights

Quartz crystal microbalance (QCM) with energy 

dissipation measurements are used to monitor changes 

in the crystal resonance frequency (film swelling) and 

its dissipation (related to its mechanical response). Four 

different regimes of film behavior were identified when 

equilibrated with aqueous hydroxide solutions (Figure 

3). In Regime I, there is no film swelling between compositions (0 < f

MAA < 0.3); at higher average degrees of 

protection (0.3 < fMAA < 0.5), Regime II is characterized 

by film swelling only; in Regime III 

(0.5 < f

MAA < 0.7), partial dissolution of a swollen film is 

observed; and finally, in Regime IV (f

MAA > 0.7), nearly 

complete dissolution is observed. 

The different responses of the films to the aqueous 

solution are a function of the copolymer composition 

and the distribution of the methacrylic acid within the 

polymer films (Figure 4). At short reaction (bake) 

times, the photoacid diffuses and reacts to a limited extent, forming domains of reacted photoresist that do not 

overlap. At this early stage, Regime I, the hydrophobic 

continuum of protected polymer, prevents penetration 

of water. The methacrylic acid content is inaccessible 
6

Combinatorial Platform for Measuring the Effect 

of Substrate Heterogeneities

To the developers of thin films for coatings, electronics, and nanotechnology, substrate heterogeneities 

can be the boon of a chemical pattern that drives 

self-assembly, or the bane of a defect that causes film 

fail-ure. We have recently developed a combinatorial 

method for measuring a key under-examined factor in thin film behavior: the “strength” of substrate 

chemical heterogeneities. Our approach merges 

soft-lithography and gradient techniques to design a 

mi-cropatterned library with gradually diminishing 

chemical contrast. As we demonstrate for the case of 

polymer film dewetting, our graded test patterns illuminates functional ranges and critical phenomenon in 

film behavior.

Michael J. Fasolka and 

Duangrut Julthongpiput 

Surface chemical heterogeneities are essential to the 

performance and behavior of substrate supported 

polymer films. For example, from a quality control 

standpoint, substrate chemical heterogeneities can be 

defects that drive instabilities, and thus failure, in polymer film products such as barrier coatings, electronics 

packaging, and resist systems. Alternately, patterned

chemical heterogeneities on a substrate can be advantageous, since they can template structures in an overlying 

film for micro- and nano-manufacturing aims. 

With respect to both of these themes, a critical parameter is the strength of heterogeneity, i.e., the magnitude of chemical differences expressed by the substrate. 

However, the effect of this factor is difficult to quantify 

and examine in a methodical manner. In response to this 

need, we have developed a breakthrough combinatorial 

library for measuring the effect of differences in surface 

chemistry, or surface energy. 

Our combinatorial test substrates consist of a pattern 

of micrometer-scale lines that exhibits a continuous 

gradient in surface energy differences against a constant 

surface-energy matrix (Fig. 1). The library is fabricated through a vapor-mediated soft lithography of an 

octyldimethylchlorosilane self assembled monolayer 

(SAM), which is then treated with a graded ultraviolet (UV)-ozonolysis. The substrate matrix material is 

SiO2. The library design includes two calibration strips 

that express the changing and static surface energy of 

the SAM pattern lines and matrix, respectively. The 

surface energy contrast, Dg=gSiO2-gSAM, along the patFigure 1: Schematic illustration (top) and calibration (bottom) 

of the gradient micropattern (Dmp) library of surface chemical 

heterogeneities. The inset graph shows g data from the calibration regions.

terned region can thus be determined by contact angle 

measurements along these calibration regions. In these 

libraries, Dg diminishes from ≈ 45 mJ/m2

 to 0 mJ/m2

(i.e., a homogeneous surface).

Previously we described how gradient micropattern 

(Dmp) libraries can be used to quantify emerging nanometrologies, such as chemical force microscopy 

[Nanoletters 5, 1535 (2005)]. This year, we illustrated 

the utility of Dmp libraries for mapping thin film phenomenon. As a demonstration case, we examined the 

dewetting of a polystyrene (PS) deposited on the micropattern. The film was 35 nm thick and annealed at 60 oC 

for 12 h.

As summarized in Fig. 2, the Dmp enables systematic 

evaluation of the film dewetting as Dg diminishes, and 

illuminates critical surface energy conditions associated 

with this behavior. The top of Fig. 2 shows a mosaic 

of optical micrographs used to assess the dewetted film 

morphology across the library. An automated optical 

Technical Highlights
7

that this crossover is largely due to competition between 

the kinetics of isotropic and pattern-driven dewetting.

By comprehensively mapping dewetting behavior, the 

Dmp illuminates functional ranges and critical values of 

substrate chemical heterogeneity for film applications. 

For example, the library shows that for self-assembly of 

PS droplet arrays, the optimum pattern strength is in the 

range of 14 mJ/m2

 < Dg < 20 mJ/m2. Likewise, to avoid 

heterogeneity-driven dewetting, surface energy differences on the substrate need to be less than 7 mJ/m2

 in 

magnitude. 

In FY06, we reported this work through an invited 

lecture at the American Chemical Society fall meeting, 

and at the 2006 International Waterborne Coatings 

Symposium.

 

For More Information on This Topic

A. Karim, J. Douglas, E. Amis (Polymers Division, 

NIST). For more information on the NIST Combinatorial Methods Center, see www.nist.gov/combi.

Figure 3: Summary of droplet density data derived from images 

in Figure 2. Three regimes of droplet behavior are indicated in 

the figure.

microscope was used to capture this fully contiguous 

set of images. Figure 2a-d shows four strips of optical 

microscopy data taken from this array. The top and bottom of each strip respectively show the matrix and SAM 

calibration regions. As expected from homogeneous areas, the dewetted film exhibits polygonal arrangements 

of droplets, the scale of which remains constant along 

the matrix, but which increases as g decreases along the 

SAM region.

Figure 2: PS film dewetting from a Dmp library. Top: Contiguous optical micrographs over the entire library. Bottom (a-d): 

images detailing the transition from pattern-directed to isotropic 

dewetting, delineated as Regions I-III. Red insets are 250 mm x 

250 mm. (ODS SAM= n-octyldimethylchlorosilane self-assembled 

monolayer)

Middle sections of Fig. 2a-d show dewetting along 

the Dmp. Highlight images (red border) detail representative droplet morphologies in each strip. The Dmp 

library reveals three regimes of behavior. The borders 

of these regimes can be delineated with precise Dg

values because the library is calibrated, and due to the 

detail provided by comprehensive optical microscopy 

measurements.

In Region I, where Dg> 14 mJ/m2

, we observe a 

pattern-directed dewetting. Region I is characterized 

by ordered arrays of PS droplets which are distributed 

along the center of both the matrix and SAM portions of 

the pattern. In Region III, where Dg < 7 mJ/m2

, isotropic dewetting occurs. In this region, film dewetting 

is not affected by the substrate pattern, and the droplet 

morphology closely resembles the polygonal arrangements observed in the calibration regions. A crossover 

between these limiting behaviors is exhibited in Region 

II (7 mJ/m2

 < Dg < 14 mJ/m2) where droplets gradually lose registry with the underlying pattern. More 

detailed analysis in this region (not shown) indicates 

Technical Highlights
8

Comparative Metrologies for Evaluating Single Wall Carbon 

Nanotube (SWNT) Dispersion

Despite claims of SWNT dispersion throughout the 

literature, there is currently no consensus on an 

absolute measure, nor has there been a methodical 

comparison of different approaches that might serve 

as a foundation for such a measure. We demonstrate 

that small-angle neutron scattering (SANS) provides 

the most direct measure of dispersion. Near-infrared 

fluorescence spectroscopy, proposed to be sensitive 

to the bundling or clustering of SWNTs, similarly 

exhibits a definitive measure. In contrast, optical absorption spectroscopy and resonant Raman scattering 

have limited sensitivity. Our study represents the first 

controlled comparison of currently accepted metrics 

for evaluating SWNT dispersion, and serves as a useful point of reference for any of the four techniques.

Jeffrey A. Fagan and Erik K. Hobbie 

Single wall carbon nanotubes (SWNTs) exhibit remarkable physical properties, and have the potential 

for profound impact over a broad range of technologies, 

from first generation applications such as conducting 

and mechanically reinforced plastics, to more advanced 

applications such as fuel cells, microelectronic components, flat panel displays, and biochemical sensors. In 

many of these applications, efficient dispersion of SWNTs at the individual nanotube level will be a prerequisite 

for optimal performance. Sources of imperfection in 

dispersing individual SWNTs are most likely bundles, 

defined here as the lengthwise aggregation or “roping” 

of tubes, and aggregates, the fractal-type networking of 

tubes in a floc. 

Of all the measurement techniques currently used to 

evaluate SWNT dispersion in solutions and composites, 

small-angle scattering is perhaps the simplest to interpret and understand. This technique directly probes 

two-point correlations in composition, and can thus distinguish true form scattering due to individual SWNTs 

from the structural scattering that arises from nanotube 

aggregates and bundles. Other more readily available 

methods, however, have also recently been used to 

evaluate SWNT dispersion, typically by focusing on 

subtle effects such as those that tube-tube interactions 

have on the optical signatures associated with transitions 

between electronic states in SWNTs of different chirality. Most notably, these techniques include optical absorption spectroscopy, near-infrared (NIR) fluorescence 

spectroscopy, and resonant Raman scattering. To extract 

maximum information from these optical techniques, 

the sensitivity of each to the level of SWNT dispersion 

must be known, especially as the limit of individually 

dispersed tubes is approached. 

Figure 1: SANS intensity as a function of scattered wave vector 

for SWNT-PAA composites cast from ssDNA stabilized SWNTs 

in unbuffered (pH 2.2) and buffered (pH 4.1) aqueous 240k 

PAA solution, where the red lines denote a power law with an 

exponent of -1, and the blue line a power law with exponent -2.5. 

The black trace has been shifted down slightly for clarity by a 

constant multiplication factor of 1.77. Error bars denote two 

standard deviations in the total experimental uncertainty.

Despite claims of SWNT dispersion throughout the 

literature, there is currently no consensus on an absolute 

measure, nor has there been a methodical comparison 

of different approaches that might serve as a foundation 

for such a measure. For this purpose, we have prepared 

model polymer composites composed of single-stranded 

deoxyribonucleic acid (ssDNA) stabilized SWNTs 

dispersed in polyacrylic acid (PAA) for an evaluation 

of the different metrologies currently used to assess 

SWNT dispersion. By varying the pH of the precursor 

PAA-SWNT solution, a systematic variation in SWNT 

aggregate dispersion is evaluated by scattering and 

optical spectroscopy. Small-angle neutron scattering 

(SANS) provides the most direct measure of dispersion. 

Near-infrared fluorescence spectroscopy, proposed to be 

sensitive to the bundling or clustering of SWNTs, similarly exhibits a definitive measure. In contrast, optical 

absorption spectroscopy and resonant Raman scattering 

have limited sensitivity. Our study represents the first 

controlled comparison of currently accepted metrics 

for evaluating SWNT dispersion, and serves as a useful 

point of reference for any of the four techniques.

SANS profiles from the two composite samples are 

shown in Fig. 1. For fully dispersed linear objects, we 

would expect a power law of -1. The unbuffered composite exhibits this power law over the entire q range 

measured, corresponding to rigid-rod behavior over a 

range of length scales between (6 and 200) nm. In comparison, the buffered composite exhibits a distinctive 

Technical Highlights
9

these two observations point to fully debundled SWNTs 

that have aggregated in the pH 4.1 composite.

From this comparison, SANS provides the most 

direct measure of nanotube dispersion, followed by 

near-infrared fluorescence spectroscopy. Resonant 

Raman scattering and optical absorption spectroscopy 

are useful, but the limits of these techniques for assessing the relative level of dispersion need to be clearly 

understood, as they provide measures with more subtle 

changes in signal. From our results, the independent 

use of any of these techniques can be improved in its 

interpretation. 

For More Information on This Topic

J.A. Fagan, E.K. Hobbie, K.B. Migler, B.J. Bauer 

(Polymers Division, NIST)

Figure 3: Comparison of NIR fluorescence plots for the SWNT 

composite samples. Despite equal SWNT concentration and near 

equal film thicknesses, the fluorescence of the unbuffered film is 

substantially larger.

upturn in scattering at low-q, approximately proportional to a power law with an exponent of -2.5, which 

is characteristic of nanotube clustering. The difference 

is both striking and conspicuous, directly demonstrating ideal nanoscale SWNT dispersion in the unbuffered 

composite, as well as the ability to tune dispersion 

through adjusting the pH of the precursor PAA solution.

Figure 2: UV-Vis-NIR absorbance as a function of wavelength 

for the same SWNT-PAA composites, where the solid/black trace 

denotes the spectra of the same concentration of ssDNA wrapped 

SWNTs in pure aqueous suspension (pH 7).

Figure 2 shows a comparison of the ultravioletvisible-near-infrared (UV-Vis-NIR) absorption spectra 

obtained from the two composites, along with that from 

the initial aqueous (pH 7) ssDNA stabilized SWNT 

suspension. The relative intensity of the peaks corresponding to the excitonic transitions for SWNTs of 

specific chirality in the NIR region of the spectrum are 

reduced from aqueous solution to buffered composite to 

unbuffered composite. The second difference between 

samples is a redshift in the position of the dominant 

absorption peak from 1134 nm in the aqueous solution 

and unbuffered composite to 1163 nm in the buffered 

composite. The changes in the peak structure leading 

to a broader and redshifted absorption in the buffered 

sample compared to the unbuffered one supports the 

SANS results that enhanced dispersion is achieved for 

the unbuffered composite. 

Fluorescence spectroscopy is also a sensitive 

measure of SWNT dispersion, since SWNT bundling 

quenches the NIR fluorescence associated with the narrow band gap of the semiconducting SWNT species. A 

comparison of the fluorescence maps for the unbuffered 

and buffered PAA composites, shown in Fig. 3, illustrates a pronounced difference in their spectral emissions. In contrast, resonant Raman scattering from the 

SWNT radial breathing mode (Fig. 4) shows very little 

difference between the two samples. In combination, 

Technical Highlights

Figure 4: Radial breathing mode resonant Raman scattering for 

the two SWNT composites.
10

Technical Highlights

Numerical Optimization of Complex Instrumentation

A novel approach has been created for the selection 

of optimal instrument parameters that yield a mass 

spectrum which best replicates the molecular mass 

distribution of a synthetic polymer. The application 

of implicit filtering algorithms was shown to be a viable method to find the best instrument settings, while 

simultaneously minimizing the total number of experiments that need to be performed. This includes considerations of when to halt the iterative optimization 

process at a point when statistically significant gains 

can no longer be expected. This work represents part 

of an effort to develop an absolute molecular mass 

distribution polymer Standard Reference Material® by 

matrix-assisted laser desorption/ionization time-offlight (MALDI-TOF) mass spectrometry.

William E. Wallace 

Typical analytical instrumentation optimization is 

performed by the analyst by simply applying the 

“factory settings” or by “optimizing by eye.” This is 

because an exhaustive search of the parameter space for 

modern instrumentation with many adjustable parameters is prohibitively time consuming. However, a variety 

of little-known mathematical methods exist that enable 

the experimentalist to optimize instrument settings without performing an exhaustive search. Broadly classified, 

these methods are all forms of numerical optimization. 

When the topology of the search space is very complex, 

for example, when it has great sensitivity to one or more 

parameters (as mass spectrometers often do), the methods used are part of the field of non-linear programming. 

They are called non-linear because some (or all) of the 

instrument parameters do not have a linear relationship 

between parameter value and measurement response. 

A simple example is laser intensity in MALDI-TOF 

mass spectrometry and its effect on signal-to-noise ratio 

where a relatively sharp threshold is observed experimentally. When the measurement outcomes (which 

in the present case are mass spectra) contain random 

noise, the mathematical methods are termed stochastic 

numerical optimization. Stochastic methods are important in mass spectrometry because all mass spectra have 

noise, this noise varies as the instrument parameters 

are adjusted, and the noise will often change across the 

spectrum. Measurement noise presents a significant 

challenge to any optimization method especially for 

cases where signal to noise is not the measurand to be 

optimized. Nevertheless, numerical optimization methods offer experimentalists a way to tune the instrument 

parameters to achieve the desired goal without having to 

search all possible parameter combinations. To measure 

the absolute molecular mass distribution of a synthetic 

polymer, it would be ideal to locate a region in parameter space where the instrument response function was 

uniform across the entire mass range. Finding the instrument response function is necessary to calibrate the 

intensity axis of the mass spectrum; that is, to go from 

mass spectrum to molecular mass distribution. If the instrument response function is uniform, then the relative 

peak areas in the mass spectrum correspond directly to 

the relative abundances of individual n-mers in the sample. A uniform instrument response function would be 

a line of zero slope; that is, it would have a derivative 

of zero. If not uniform, the instrument response function could slowly vary across the mass range, preferably 

linearly with mass. The optimal conditions are those 

that give the simplest (or flattest) instrument response 

function; that is, the one with the smallest derivative.

To measure the instrument response function, a gravimetric mixture was made of three low polydispersity 

polystyrenes that were very close in average molecular 

mass. The optimal instrument settings were those that 

provided the closest match between the total integrated 

peak intensity of each of the three polymers with the 

known gravimetric ratios. Note that there is no guarantee (or even assumption) that the optimal instrument 

settings that give the flattest instrument response function will also yield optimal signal to noise ratios. In fact 

there is no reason to believe that a search for the instrument settings that optimize the response function will 

not lead into a region where the mass spectra become so 

noisy as to make peak integration impossible. Thus, to 

find the optimal instrument settings, we used stochastic 

gradient approximation methods. These methods have 

proven to be extremely robust in cases where the measured data are very noisy.

Optimization is performed by defining an objective function J(x) where x is a vector consisting of the 

instrument parameters. In our case, the objective function was the sum of the squared differences between the 

amount of each polymer in a mixture created gravimetrically, and the amount of each polymer in the mixture 

found by mass spectrometry. When this function is zero, 

the gravimetric concentrations match the concentrations found by mass spectrometry, and the instrument 

is optimized. The function J(x) is a noisy function with 

respect to the parameter vector x, due to the inherent 

statistical noise in the mass spectra. This complicates 

the task of numerically locating the minimum of J(x). 

The fact that each evaluation of J(x) requires an experiment, and subsequent interpretation of experimental 
11

coupled; that is, varying one requires all others to vary 

in response if J(x) is to move closer to its optimal value. 

Thus, the vector xi+1 has a tendency to be normal to the 

vector xi

 (in its five-dimensional space). The laser intensity varies the most, and would seem to be the dominant 

variable. It seeks its stable value before the other parameters can settle down to find their optimal values.

results, means that there is a high cost for each function 

evaluation. This further complicates any numerical procedure that seeks to minimize J(x). Finally, there are values of the vector x (for example, out of range instrument 

parameter settings), for which J(x) cannot be evaluated. 

One method for minimizing noisy functions that seeks 

to approximate the gradient of the objective function is 

called implicit filtering. Broadly speaking, this method 

uses a very coarse grained step-length to build a finite 

difference approximation to the gradient of J(x). This 

gradient is then used to generate steep-descent directions for a minimization process. As iterates draw closer 

to the solution, and the objective function decreases, the 

finite difference step-length is decreased until it approaches a number small enough to suggest convergence 

of the algorithm to the minimum value.

Figure 1: The objective function J(x) and its local gradient value 

as a function of iteration step.

In Fig. 1, there is an initial steep drop in the objective function flowed by gradual movement to the 

optimal parameter settings. The gradient of the objective 

function also decreases steadily as the optimum point 

is approached. These monotonic responses indicate 

that the optimization routine is stable. At the optimum 

value, the objective function is so small that it cannot be 

reduced further due to the inherent noise in the measurement. Likewise, the step size indicated for each parameter at this point is so small as to be below the precision 

of the instrument’s settings.

In Fig. 2, the values oscillate about their final values 

as the optimization proceeds. The laser intensity undergoes the greatest excursions: decreasing in the first two 

iterations, returning to its initial value in the third iteration, and then increasing in the fourth iteration before 

settling into its final value. The four other parameters 

make an excursion in the direction of their final values 

in the first iteration, return to their initial value in the 

second iteration, and find the equilibrium values by 

the third iteration. This zigzag pattern is characteristic 

of the non-linearity of the system. This non-linearity 

arises from the fact that the instrument parameters are 

Figure 2: Individual instrument parameter values as a function of 

iteration number. 

A specialized noise-adapted filtering method has 

been applied to the problem of finding the optimal 

instrument parameters for a MALDI-TOF mass spectrometer. Finding the optimal instrument parameters was 

a critical step in creating an absolute molecular mass 

distribution polymer Standard Reference Material®. The 

task of tuning the instrument’s five main parameters 

could not be approached by exhaustive search methods, 

given the amount of effort needed to take and to reduce 

the data in a statistically meaningful way at each set 

of instrument parameters. Additionally, this method 

produces an estimate of the sensitivity of each optimal 

parameter not available to traditional exhaustive search 

methods. Each of the subtasks in the process could be 

automated to create an integrated closed-loop optimization scheme. 

For More Information on This Topic

W.E. Wallace, K.M. Flynn, C.M. Guttman (Polymers 

Division, NIST); A.J. Kearsley (Mathematical and Computational Sciences Division, NIST)

See www.nist.gov/maldi for more information.

Technical Highlights
12

Platform for Characterizing Defects in Magnetic Nanoparticles

Nanoparticles are an important component of emerging technologies for medical diagnostics, targeted 

therapies, biomolecular detection, and next generation electronics. The efficacy of nanoparticles 

in these applications is challenged by the lack of 

methods to characterize the strength and homogeneity of nanoparticle interactions. We are developing a 

measurement platform to rapidly quantify nanoparticle interactions for large assemblies of nanoparticles, 

providing statistics on the distribution in strength of 

interaction, and the capability to determine the nature 

and concentration of defective particles.

Ronald Jones and Jason Benkoski 

Nanoparticles with diameters of (1 to 100) nm are widely sought as enablers of advanced technologies for medical diagnostics and therapies, chemical and 

biological sensors, and microelectronics. Many of these 

technologies rely on the enhanced optical, magnetic, and 

chemical functionality inherent in particles of nanometer 

scale. However, properties of nanoparticles are highly 

sensitive to particle size, shape, and chemical composition. As a result, small variations in the manufacturing 

process can produce defective particles with undesirable 

properties, resulting in a loss of device functionality. 

The advancement of suitable manufacturing techniques 

is currently limited by a lack of measurement platforms 

capable of rapidly characterizing defects in nanoparticle 

interactions over large particle quantities.

A specific class of nanoparticles that has received 

significant interest is magnetic nanoparticles (MNPs). 

The particles typically consist of a metallic core with a 

polymeric flocculant coating. Recent advances in synthetic methods make the production of large numbers of 

MNPs with nearly monodisperse diameters and homogeneous compositions feasible. However, scaling established methods to characterize the interaction strength 

of a single MNP are challenged by the large numbers 

of particles and their small dimensions, precluding a 

measurement of defect concentration and homogeneity 

in manufacturing. As a result, indirect and often timeconsuming measurements of size dispersity are used to 

infer homogeneity of interactions. 

We are developing a methodology to rapidly characterize the homogeneity of large numbers of particles 

to quantify the number density of defective particles. 

Defective particles are particles with vanishing magnetic 

moment or particles with undesirable polarity. In many 

applications, for example, the synthesis attempts to create large batches of dipolar particles. However, small 

variations in synthetic conditions can result in varying 

concentrations of quadripolar particles, or even particles 

with higher moments of polarity.

Figure 1: Schematic depicting the crosslinkable oil-water platform for characterizing nanoparticle interactions. The platform 

provides a rapid method to quantify the character and number of 

defects in magnetic interactions for a large number of particles. 

A wide range of particle size and chemistry are available to this 

methodology due to the ability to assemble oil soluble (top route) 

and/or water soluble (bottom route) particles. 

Rather than measuring the properties of individual 

particles in a serial fashion, our methodology measures 

the shape and size of nanoparticle assemblies, where 

assemblies can consist of 10’s or 100’s of nanoparticles. 

Dipolar MNPs are known to assemble as long strings in 

solution when their magnetic moment interactions exceed other isotropic forces, including thermally induced 

vibrations and isotropic van der Waals interactions. In 

contrast, non-polar particles or multipolar particles form 

non-linear assemblies. Defects in MNPs are therefore 

characterized by the linearity within assemblies. The 

methodology described here uses a novel platform to 

freeze-in thousands of assemblies for characterization 

using scanning probe or electron microscopies. By 

measuring a large number of assemblies, where each 

assembly can contain 1000’s of particles, high precision 

statistics of defect concentration are obtained. 

As shown in Fig. 1, MNP assembly occurs at an oil/

water interface, in which the oil phase can be flashcured upon ultraviolet (UV) radiation exposure. The 

platform utilizes a photopolymerizable oil phase, 

1,12-dodecanediol dimethacrylate (DDMA), to provide 

a portable and characterizable “snapshot” of the assembly process. The use of a low viscosity oil and water 

phase allows MNP assembly to proceed rapidly. With 

an appropriate chemistry and light source, the assemblies are frozen in less than 1 s from initial exposure, 

with minimal volume change of the oil phase. Freezing 

of the MNP assemblies precludes the alteration of asTechnical Highlights
13

sembly structure by capillary forces at the air/water interface. The resulting sample is glassy, allowing storage 

for long-time or future measurements, and is amenable 

to a wide range of characterization platforms, including 

scanning probe and electron microscopies. Its transparency to a wide range of electromagnetic wavelengths 

will enable the advancement of scattering and optical 

imaging based characterization platforms. 

While development has focused on nanoparticles, a 

wider range of particle interactions can be studied under 

identical conditions, including much larger colloidal 

and latex particles, particles of varying polarity, and of 

varying composition, including metallic and polymeric. 

Particles investigated to date include nonpolar 0.39 mm 

poly(methyl methacrylate) latex spheres, nonpolar 

10 mm polystyrene latex spheres, highly polarizable 

5 nm Au nanocrystals, dipolar 10 nm CdTe quantum 

dots, and magnetic 25 nm magnetite nanoparticles. As 

shown in Fig. 2, the range of structures expected in 

these assemblies is large, making the methodology generalizable to a large range of particles.

In Fig. 3, assemblies of both micrometer scale 

polymer particles and nanometer scale metallic particles 

provide immediate qualitative and quantitative characterizations of average interaction strength, while providing data on defect concentrations. Specifically, charging on polystyrene particles as a result of the sample 

preparation method dramatically changes the assembled 

structure from dense, two-dimensional aggregates to 

highly branched networks. The charging appears to be 

uniformly applied across all particles. In contrast, gold 

nanoparticles follow a well defined random walk characteristic of directional forces. Similarly sized magnetite 

particles feature regions of dense packing, indicating the 

presence of particles with lower magnetic moment and/

or multipolar character.

Figure 4: Top: Optical micrographs of 10 mm PS spheres protruding from the oil/water interface after crosslinking. Shown are 

uncharged particles (left) with characteristic two-dimensional 

dense assemblies. In contrast, a small charge added to the 

particle creates a highly branched assembly (right). Bottom: 

Atomic force microscope phase image of assemblies of gold (left) 

and magnetite (right) nanoparticle assemblies. While the gold 

particles show a characteristic linear assembly, the presence of 

dense assembled regions in the magnetite particles may indicate 

the presence of particles with reduced magnetic moment.

We have demonstrated the use of a DDMA/water 

interface as a platform for characterizing defects in 

the magnetic interactions of particles with nanometer 

scale dimensions. The methodology characterizes the 

interaction strength of a large number of particles by the 

examining the structure of assemblies of 10’s or 100’s of 

nanoparticles at an oil/water interface. Without the ability to preserve snapshots of the aggregated structures by 

this process, the rapid movement of the particles would 

challenge microscopy characterization techniques. 

The high interfacial tension of the oil/water interface 

provides a strong driving force for the segregation of 

many different particle types, despite large differences 

in charge, polarizability, size, and surface chemistry. It 

therefore allows one to compare the aggregation of a 

wide variety of nanoparticles under remarkably similar 

conditions.

For More Information on This Topic

J. Douglas, A. Karim (Polymers Division, NIST); J. 

Pyun (University of Arizona)

Figure 2: Representative structures from assemblies of particles 

with varying types and strength of interaction.

Technical Highlights
14
15

Program Overview

Advanced Manufacturing Processes

The competitiveness of U.S. manufacturers depends 

substantially on their ability to create new product 

concepts and to quickly translate such concepts into 

manufactured products that meet their customers’ 

increasing expectations of performance, cost, and 

reliability. This is equally true for well-established 

“commodity” industries, such as automotive, aerospace, 

and electronics; for materials suppliers of aluminum, 

steel, and polymers; and for rapidly growing industries 

based on nanotechnology and biotechnology. In support 

of these industries, the NIST Materials Science and 

Engineering Laboratory (MSEL) is developing robust 

measurement methods, standards, software, and process 

and materials data needed for design, monitoring, 

and control of new and existing materials and their 

manufacturing processes. 

Our research is conducted in close collaboration 

with industrial partners, including industrial consortia, 

and with national standards organizations. These 

collaborations not only ensure the relevance of our 

research, but also promote rapid transfer and utilization 

of our research by our partners.

Contact: Michael J. Fasolka

Quantitative Polymer Mass Spectrometry Project Meeting

NIST Combinatorial Methods Center
16

Combinatorial and high-throughput (C&HT) methods 

hold great potential for making materials research 

more productive, more thorough, and less wasteful. 

However, significant technical barriers prevent the 

widespread adoption of these revolutionary approaches by industry. Through creative, cost-effective 

measurement solutions, and by using a customer 

outreach model designed for fruitful collaboration, 

the NIST Combinatorial Methods Center (NCMC) 

strives to ease the acquisition of C&HT techniques by 

the materials research community. 

Michael J. Fasolka and Carol E. Laumeier 

The NIST Combinatorial Methods Center (NCMC), 

now in its fifth year, continues to be an innovative 

resource for industrial materials researchers striving to 

acquire combinatorial and high-throughput (C&HT) 

measurement capabilities. The NCMC fosters adaptation of C&HT methodologies through two complementary efforts. First is a research program, centered in the 

Polymers Division’s Combinatorial Methods Group, 

which develops and demonstrates C&HT measurement 

solutions for the discovery and optimization of complex materials products, including polymer coatings 

and films, adhesives, cosmetics, and structural plastics. 

Moreover, in conjunction with other Polymers Division 

Groups, a growing aspect of NCMC research provides 

C&HT methods for emerging technologies such as 

nanostructured materials, organic electronics, and biomaterials. All NCMC research is published in the public 

domain.

Advanced Manufacturing Processes

NIST Combinatorial Methods Center 

A Pioneer and Partner in Accelerated Materials Research

Figure 1: NCMC Awardees of the Department of Commerce 

Silver Medal for Customer Service in 2006. From left to right: 

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

Second, to complement its research, the NCMC 

conducts outreach efforts focused on disseminating new 

measurement methods to industry, assessing emerging industrial C&HT metrology needs, and forming a 

community of technology stakeholders. The NCMC 

leverages a unique, “non-proprietary” consortium 

model, the development and success of which garnered 

a Department of Commerce Silver Medal for Customer 

Service (see photo). This model promotes open discussion of the metrology issues that face industrial stakeholders, and a focus on the fundamental, common needs 

of this community. NCMC consortium members (see 

table below) are served through a series of semi-annual 

workshops, a dedicated website, and documents that 

detail NCMC instrumentation. FY06 activities included 

two additions to the NCMC workshop series. NCMC-8: 

Polymer Formulations II, held Oct. 27-28, 2005, assessed opportunities in microscale measurement technologies for advancing formulations science, gauged 

related measurement needs, and reported the achievements of the Polymers Formulations project. NCMC-9: 

Combinatorial Methods for Nanostructured Materials, 

held Apr. 24-25, 2006, determined key metrology needs 

in industrial research of nanostructured polymeric materials, and set priorities for developing C&HT methods for these systems. NCMC-9’s Workshop Report, 

NISTIR 7332, is available on the NCMC website (see 

below). 

In addition, non-proprietary “Focus Projects” enable 

member companies to collaborate with NCMC researchers to produce more specific measurement solutions. Two 

NCMC Focus Projects were completed in 2006. The 

first, co-funded by Procter and Gamble and National 

Starch, resulted in a powerful microfluidic approach for 

measuring interfacial tension. The second, sponsored 

by Intel and National Starch, resulted in combinatorial 

libraries that assess the performance of epoxy adhesives 

for flip-chip electronics. A new Focus Project, with the 

goal of developing HT measurements of polymer hydrogel 

mechanics, was launched with Vistakon, a manufacturer 

of contact lenses.

NCMC Members (*New in FY2006)

Air Products & Chem. Insight Faraday*

Arkema Inc. Intel

Avon* L’Oreal

BASF PPG Industries

Bayer Polymers Procter & Gamble

Dow Chemical Company Rhodia

ExxonMobil Research Symyx Technologies*

Honeywell International Unilever*

Hysitron International Univ. of Southern Miss.

ICI/National Starch & Chem. Veeco Metrology

For more information, please visit the NCMC 

website at www.nist.gov/combi.

Contributors and Collaborators

E.J. Amis, K.L. Beers, A. Karim, C.M. Stafford (Polymers Division, NIST)
17

Advanced Manufacturing Processes

Polymer Formulations: 

Soft Materials Measurements on a Chip

Complex structured fluids, also known as formulations, have been an important part of modern life for 

many years, even though they are poorly understood. 

Only recently has industry begun to control and design these materials to obtain novel, valuable properties, but scientists are overwhelmed by the composition and processing variable space required. We 

develop and demonstrate high throughput methods 

to advance polymer formulations science through the 

fabrication of microscale instrumentation for measuring physical properties of complex mixtures.

Kathryn L. Beers 

Significant progress was made this year in our efforts to build microfluidic instrumentation for the 

measurement of polymer solutions. New measurement 

capabilities were developed, several collaborators 

visited NIST for extended periods to learn new 

technologies, and high impact publications resulted 

from our work. 

Dynamic light scattering (DLS) remains one of 

the most popular and powerful tools to measure size 

in solutions containing nanoparticles (such as latexes 

and suspended inorganics) and nanostructures (such 

as micelles and vesicles). Several prototypes were 

constructed that enable particle sizing in the range of 19 

nm to 107 nm using less than 150 μL of solution (Figure 

1). Rapid measurements using these devices surveyed 

a range of solution composition and temperature to 

determine surfactant dissolution behavior. Simple 

extension of these measurements will enable phase 

mapping of nanostructured solutions. The instruments 

were designed to be integrated with existing NIST 

techniques for synthesis, spectroscopy, and image 

analysis of polymer solutions in microfluidic devices. 

the developing industry.

Progress was also made on additional methods, including the validation and integration of droplet library fabrication, photopolymerization, and shrinkage measurements 

for methacrylate-based resins [The Analyst 131, 1027 

Figure 2: : Illustration of a solution gradient stabilized in a 

confined microchannel (left) that was used to construct a polymer 

brush surface with a gradient in statistical copolymer composition (right).

Figure 1: Diffusion measurements and particle sizing of latex 

spheres and block copolymer micelles conducted on a microfluidic device. Inset: Photograph of a fixed, multi-angle device.

(2006).]. Correlations between monomer composition, 

extent of conversion, and shrinkage were matched with 

off-chip measurements.

Microfluidic confinement has also enabled the stabilization of solution gradients, as validated by fiber-optic 

Raman spectroscopy. The power of such a solution 

gradient was demonstrated by fabrication of a statistical 

copolymer brush surface containing a gradient in composition [Fig. 2; Adv. Mat. 18, 1427 (2006)], a gradient 

heretofore unobtainable, and thus valuable in characterizing thin film and nanoparticle behavior.

Visiting scientists from CSIRO and BASF performed 

research in the NIST laboratories this year. Microfluidic 

device design, measurement strategies for polymerization, and use of microscopy and spectroscopy tools were 

transferred to both organizations. A new joint project 

on the library design and characterization of surfactant 

solutions will eventually be conducted at CSIRO using 

NIST technology.

Contributors and Collaborators

T.Q. Chastek, C. Xu, S.E. Barnes, K.A. Page, M.J. 

Fasolka, E.J. Amis (Polymers Division, NIST); S. Müssig (BASF); C. Fong (CSIRO)
18

Quantitative Polymer Mass Spectrometry 

Matrix-assisted laser desorption ionization time-offlight mass spectrometry (MALDI-TOF-MS) has been 

demonstrated as a method for absolute molecular mass 

distribution measurement of synthetic polymers via the 

creation of Standard Reference Material® 2881. This 

means determining a comprehensive uncertainty budget 

for a complex measurement technique that must include 

both Type A and Type B uncertainties.

William E. Wallace 

Currently, all absolute molecular mass polymer 

standards provide a single moment (e.g., Mn

or Mw) of the molecular mass distribution (MMD). 

(By absolute it is meant that the standard is based 

on direct measurement of a physical property, and 

not on calibration against another polymer.) We 

have created a comprehensive strategy to create an 

absolute molecular mass distribution polymer Standard 

Reference Material® using matrix-assisted laser 

desorption/ionization time-of-flight (MALDI-TOF) 

mass spectrometry. To create such a standard, our 

methods must be demonstrably free of operator bias 

(intentional or unintentional). Furthermore, the Type 

A (“random”) and Type B (“systematic”) uncertainties 

must be determined for each part of the experiment. 

The required unbiased, repeatable steps are: 1) sample 

preparation, 2) instrument tuning, 3) data collection, and 

4) data analysis. These steps ultimately lead to a signal 

intensity calibration function (and, most importantly, its 

associated uncertainty) that relates the true MMD of the 

analyte to the MMD measured by mass spectrometry.

We used a narrow polydispersity polystyrene initiated with an n-octyl group, and having a peak mass (Mp

) 

of 9 000 u. To this polymer we gravimetrically mix 

two n-butyl-initiated polystyrenes, one having an Mp

 of 

6 000 u and the other an Mp

 of 12 000 u. The different 

end groups allow us to distinguish between different 

peaks in the mass spectrum, as shown in the top panel 

of the figure (right). By controlling the gravimetric mix, 

we created a signal-intensity calibration curve using a 

Taylor’s expansion around a central mass peak as our 

mathematical model. We used electrospray methods to 

create uniform MALDI targets that are free of “sweet 

spots” that could be reproducibly made, and whose 

preparation could be described precisely. Removal of 

the gross uncertainties inherent in typical MALDI sample preparation methods (e.g. “hand spotting”) is critical 

for quantitation work. With gradient-free numerical 

optimization methods (see Technical Highlight in this 

Report) we located the instrument parameter settings 

in 5-dimensional space (extraction, lens, and detector 

voltages; laser intensity; and extraction delay time) that 

give the least bias in the molecular mass distribution, 

as well as the Type B uncertainties for the measurement. We do this by comparing the difference between 

the gravimetric mixture ratios with the ratios found by 

mass spectrometry until an optimal set of instrument settings is found. Data collection is randomized to prevent 

unknown changes in experiment procedure or instrument performance from creating a systematic bias in the 

data over periods of hours, days, and weeks. Using our 

time-series segmentation method, MassSpectator (see 

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 (2004) and A.J. Kearsley, W.E. Wallace, and 

C.M. Guttman, “A Numerical Method for Mass Spectral 

Data Analysis,” Applied Mathematics Letters 18, 1412 

(2005), we automatically identify and integrate mass 

peaks to give a MMD, as shown in the bottom panel of 

the figure. Finally, using standard additions of the three 

polystyrenes (and two other polystyrenes with intermediate average masses), we created a signal intensity 

calibration curve as a function of molecular mass across 

the distribution. Variations in relative ratios of the three 

polymers let us determine the Type A uncertainty in the 

calibration curve.

Contributors and Collaborators

M.Y.M. Chiang, S. Guo, J.H. Kim, E.A. Wilder, 

W. Zhang (Polymers Division, NIST); Daisuke Kawaguchi (Nagoya University); Gareth Royston (University of 

Sheffield)

Advanced Manufacturing Processes
19

Program Overview

Biomaterials

Rapid development of medical technologies depends 

on the availability of adequate methods to characterize, standardize, control, and mass produce them. To 

realize this goal, a measurement infrastructure is needed 

to bridge the gap between the exponentially increasing 

basic biomedical knowledge and clinical applications. 

The NIST Materials Science and Engineering Laboratory (MSEL) Biomaterials Program is a collaborative effort creating a new generation of performance standards 

and predictive tools targeting the metrology chain for 

biomedical research. 

Today, all areas of materials science confront real 

systems and processes. In the biomaterials arena, we 

can no longer advance science by simply studying ideal 

model systems. We must comprehend complex realistic 

systems in terms of their structure, function, and dynamics over the size range from nanometers to millimeters. 

MSEL is uniquely positioned to make a major contribution to the development of measurement infrastructure 

through three focus areas: Systems Biology, Bioimaging, and Nanobiosensing.

Contact: Marcus Cicerone
20

3D Tissue Scaffolds 

We are developing reference materials and noninvasive analytical methods to meet measurement needs 

related to 3D tissue engineering (TE). These methods and reference materials will replace destructive 

end-point methods currently in use, and in so doing, 

will facilitate more efficient and effective TE scaffold 

testing and design. 

Marcus T. Cicerone 

Result-focused rational design of 3D TE scaffolds, one Holy Grail of tissue engineering, requires first 

that cell response can be monitored to known conditions 

within the bulk of the scaffold. We are developing noninvasive characterization methods that will replace some 

of the destructive end-point methods currently in use. 

The methods we are developing will result in quantifiable, reliable metrics that are relevant to success of TE 

constructs in properly supporting cell and tissue growth. 

Cells in 3D constructs respond to perfusion conditions, 

local surface morphology, and surface chemistry, as well 

as a number of other mechanical, chemical, and electrical stimuli. Work under this project focuses on characterizing the first three of these factors, as well as cell 

response to them.

Reference Scaffold and Structural Analysis – 

There is a continuing need for reference materials 

and standard artifacts in this field. We are in the final 

stage of generating a 3D reference scaffold for porosity. These artifacts will be used as standards against 

which to evaluate scaffold porosity and permeability; 

the primary characterization data are permeability and 

porosity. Analysis of 3D images obtained by micro-computed tomography (mCT) plays a major role in scaffold 

characterization. We expect to complete an interlaboratory comparison for determining confidence limits in 

specifications by December 2006. The work is a collaborative project through ASTM (Task Force F04.42.06). 

This work has also spurred generation of an ASTM draft 

guide for scaffold characterization (in preparation).

In-situ Cell and Tissue Imaging – Optical and 

other imaging modes have revolutionized research into 

many areas, including cell-material interactions. Optical imaging in 3D TE constructs poses two important 

problems: the rapidly dividing cells are sensitive to 

high light flux, and 3D scaffolds generally provide poor 

platforms for high-resolution imaging due to opacity. In 

addressing the former, we continue to develop broadband coherent anti-Stokes Raman scattering microscopy 

(m-CARS) as a powerful, noninvasive method for determining cell health and development within tissue scaffolds. Progress this year has included a new method to 

eliminate nonresonant background so that weak spectral 

features in the fingerprint region can be detected [Kee et 

al., Optics Express 14, 3631 (2006)]. 

We have demonstrated a solution to another major 

hurdle for imaging in 3D scaffolds by developing an 

optically clear tissue scaffold. This scaffold is fabricated by salt-leaching from a photopolymerized glassy 

polymer that has been used in dental applications. Characterization of these scaffolds with respect to morphology and mechanical properties has been submitted to 

Biomaterials (S. Lin-Gibson, et al.). A report on behavior of osteoblast cells on these scaffolds has been 

published [F.A. Landis et al., Biomacromolecules 7, 

1751 (2006)].

Figure 1: Optically clear salt-leached scaffolds made with 

varying porosity and pore size allows large range in mechanical 

properties as well as clear imaging of cells as far as 400 mm into 

scaffold. 

Applicability of 2D Results to 3D Scaffolds – 

Surfaces of many 3D scaffold types present to cells as 

having varying degrees of curvature, however analysis 

of cell response to surface chemistry is most conveniently performed on flat surfaces. We have shown that 

in some cases the results obtained in 2D are retained in 

3D scaffolds. Distinct compositions of phase-separated 

blends of tyrosine-derived polycarbonates have been 

shown to elicit marked differences in proliferation and 

differentiation response in 2D. We have recently demonstrated that these results carry over to 3D. 

Contributors and Collaborators

Y.M. Chiang, M.T. Cicerone, J. Cooper, J.P. Dunkers, S. Lin-Gibson, F. Phelan, J.R. Smith, T. Dutta Roy, 

F.Wang, T.W. Kee (Polymers Division, NIST); J. Kohn 

(Rutgers)

Biomaterials
21

Combinatorial Methods for Tissue Engineering

The goal of this project is to develop measurement 

methods and associated materials to characterize 

the interactions, at the surface, between cells and 

biologically active materials for use in optimizing 

tissue-engineered products.

Matthew L. Becker 

The diversity of functional species, distinct structural features, and multiple hierarchies within classes of 

functional biomaterials create significant challenges to 

characterization. Solutions to these challenges require novel approaches to measurements, including the 

development of new methods and instrumentation. Our 

program seeks to develop combinatorial tools and methods to identify the critical physico-chemical properties 

influencing the biological performance of biomaterials. 

Morphology Gradient Libraries - We are fabricating single and multi-variable continuous gradient libraries to generate linear variations in important 

physical properties, including roughness, surface energy, 

crystallinity, and phase separation. This approach affords opportunities to quickly identify compositions and 

physical properties exhibiting favorable cell-material 

interactions using automated characterization and data 

acquisition methods, and narrow the physical parameter space where higher levels of characterization are 

required.

Bioactive Ligand Gradients - We are designing 

bioactive ligand density gradients to identify optimum 

lignad densities for directed cell adhesion, proliferation, and differentiation. We are combining traditional 

and automated bio-imaging techniques with emerging 

microanalytical techniques to obtain data that links 

substrate properties with morphology and biochemical 

signatures of protein and RNA expression in small cell 

populations. 

Cell morphological, viability, and biomarker measurements are being measured on similar 2D and 3D 

substrates and their results compared among them and 

with existing data of in vivo samples. These welldefined substrates are being used to push the sensitivity 

limits of current methods and if successful, the correlations will increase the ability of in vitro cell-based 

measurements to predict cellular behavior in vivo. 

We anticipate these efforts will provide the foundation for a framework, which would guide the early assessments of in vitro and in vivo material performance, 

and establish a series of metrologies for biocompatibility 

thresholds. These measurement solutions would provide 

useful guidance to materials development efforts, manufacturing process optimization, and regulatory agencies.

 

Contributors and Collaborators

C.G. Simon, N.D. Gallant, M.J. Kipper, K.E. 

Roskov, M.D. Roy, M.T. Cicerone (Polymers Division, 

NIST); J. Kohn, P. Holmes (New Jersey Center for 

Biomaterials, Rutgers University); D.L. Kaplan (Tissue 

Engineering Resource Center, Tufts University)

Figure 2: The plot above depicts cell area and aspect ratio as 

a function of position on a peptide functionalized self assembled 

monolayer possessing a gradient in RGD density, a peptide commonly used in cell adhesion applications.

Biomaterials

One of our focus areas is to develop physical and 

spectroscopic methods to measure the extent and associated physico-chemical changes resulting from phase 

separation. Phase separation is a critical component 

in solution processing, materials optimization, and 

medical device manufacturing. The various changes 

in properties have been shown to influence preferential 

protein adsorption profiles that influence the biological 

responses.

Figure 1: Diffraction patterns collected over a range of sample 

rotation angles. The distance between the pronounced horizontal 

ridges provides the sidewall angles β, while the relative intensity

and placement 
22

Dental Polymers and Composites: 

Developing a Test Suite for Total Materials Characterization 

The objective of this project is to develop combinatorial platforms for characterizing salient material 

properties of candidate dental polymers. These platforms will aid others in the development and optimization of polymers for restorative composites with 

improved performance.

Sheng Lin-Gibson and Nancy J. Lin 

Polymeric dental composites are widely used in the restoration of anterior lesions and small to medium 

sized defects in the posterior region of the mouth. While 

significant improvements have been made in the composites’ properties, their long term performance is still 

less than optimal. A significant effort has been devoted 

to improve the composite properties by designing new 

dental polymers. For the matrix polymer alone, a large 

number of material and processing parameters influence the material properties and biological responses. 

High-throughput and combinatorial methods are ideal 

for the purpose of characterizing these materials because 

of their faster data acquisition and ability to span a wide 

parameter space, and equal processing conditions for a 

given specimen, resulting in a lower experimental error 

rate. 

2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) 

phenyl] propane (BisGMA) and triethylene glycol 

dimethacrylate (TEGDMA) are two commercially 

important dental monomers. 2D gradient samples of a 

model dental polymer consisting of a dimethacrylate 

mixture (BisGMA and TEGDMA) varying in composition and conversion were fabricated (Figure 1). A broad 

conversion range was obtained for all compositions. 

The conversions were measured using near infrared (IR) spectroscopy, and the mechanical properties 

(elastic modulus and hardness) were determined using 

nanoindentation with the continuous stiffness method. 

Our previous work demonstrated a strong correlation 

between vinyl conversion and mechanical properties of 

the cross-linked polymer.

Figure 1: Fabrication of 2D gradient samples.

Two indicators for material biocompatibility are 

cell viability and cell attachment density, both of which 

can be quantified (Figure 3). In general, cell viability 

remained high until the conversion fell below 44 %. A 

high degree of cell attachment required a higher conversion. Similar trends were seen for all compositions.

Biomaterials

Figure 2: Fluorescent microscopy showing viability of cells cultured on 2D gradient samples. Live cells are stained green, and 

dead cells are stained red. Scale bar = 50 μm.

Figure 3: Cell viability (left) and cell density (right) measured 

as a function of methacrylate conversion for a single composition. 

Continuous variable gradients are efficient for screening biological effects arising from the composition and 

degree of conversion. Other potential combinatorial/

high-throughput techniques are also being evaluated for 

their ability to screen structure-properties relationships 

in dental materials, including relating conversion to 

polymerization shrinkage.

Contributors and Collaborators

J.M. Antonucci (Polymers Division, NIST)

Cell viability on the 2D gradient samples was assessed using fluorescence microscopy (Figure 2). As 

the degree of conversion increased, cell attachment 

and viability increased. Compositions with increasing 

TEGDMA content had increased cell viability, but the 

effects were subtler.
23

Metrology for Biomechanical Effects on Cell/Material Interactions

Many tissue engineered medical products are cultured 

under mechanical stimuli to mimic the physiological 

environment. This approach is currently addressed 

in an ad hoc way to demonstrate how cells respond 

under macroscopic stress conditions. However, stress 

at the cellular level is not well characterized. This 

project will develop a measurement infrastructure 

consisting of instrumental techniques, mathematical 

modeling, and characterization protocols to 

determine local stresses on cells from macroscopic 

stresses and to quantify the effect of these stresses 

on cell morphology, phenotype, and biochemical 

signaling.

Joy P. Dunkers 

Metrology Development – Mechanotransduction 

is the process by which cells convert mechanical 

stimuli into biochemical signals. Most cell functions are 

influenced by mechanical stimuli: proliferation, migration, differentiation, apoptosis, and protein synthesis. 

Much work has been done to identify the specific 

molecular signals activated for various phenotypes, 

and to correlate the macroscopic stress/strain on the 

flexible substrate to cell response. However, there are 

currently no standard protocols on how these studies 

are conducted, or how the real time stress/strain local 

to the cell is determined. We believe that the existence 

of many apparently contradictory results in the literature is related to this lack of consistent analysis. We are 

creating a measurement platform to quantify the actual 

stress transferred to the cell and to correlate it to cellular 

response in 2-D and 3-D cultures. This platform will 

be useful to researchers, as well as to regulatory agencies, as they seek new methods to test tissue engineered 

medical products.

In this investigation, smooth muscle cells were 

selected as the model system to examine the transition 

from synthetic to contractile phenotypes under biaxial 

stress. A combination of culture techniques, bioreactor designs, and cell-based assays were used to image, 

quantify, and predict biological responses as a function of mechanical stimuli. Studies include dynamic 

culture testing, advances in optical and fluorescence in 

vitro imaging, genetic profiling, and mathematical/computational modeling. This research platform expands 

across the tissue engineering spectrum, starting from the 

simplest case of non-confluent cells to proliferation and 

organization into tissues. 

This year we developed methods to robustly attach

and thoroughly characterize extracellular matrix (ECM) 

proteins on the deforming substrate. Here, the ECM 

protein is fibronectin (FN) grafted to the deforming 

polydimethylsiloxane via a silane coupling agent. We 

characterized the FN coating in terms of surface roughness, uniformity, thickness, conformation, and rigidity. 

Response of smooth muscle cells (shown below, stained 

for focal adhesions and actin cytoskeleton) to the grafted 

FN was characterized by proliferation and live/dead 

assays. These baseline results will serve to evaluate the 

durability of the attached FN after the biaxial stretching.

Mathematical Modeling – Previous in vitro studies using cells cultured on substrates show that 1) cells 

sense the variation in substrate rigidity by modifying 

their morphology; 2) cells subjected to uniaxial stretch 

elongate perpendicular to the stretch direction; and 3) 

cells show preference to specific substrate stiffness on a 

stiffness gradient (durotaxis).

Guided by this, we developed a mathematical model 

of cell-substrate adhesion to explain the dependency of 

cell morphology and migration on substrate mechanics. 

The hypothesis is that the morphology of a cell adhering to a substrate is characterized by the competition 

between cell and substrate strain energies and interfacial 

energy (work of adhesion) at the cell periphery. The 

final configuration of the cell morphology is determined 

by the total free energy minimum of the cell/substrate 

system. This work is discussed further in the Highlights section of this report. [Yong Ni and Martin Y.M. 

Chiang, “Cell Morphology and Migration Linked to 

Substrate Rigidity,” Soft Matter 3, 1285 (2007).]

 

Contributors and Collaborators

L. Pakstis, M.Y.M. Chiang, Y. Ni, N. Lin, L. Henderson, J. Cooper, M. Cicerone (Polymers Division, NIST); 

T. Quinn, T. Oreskovic (Materials Reliability Division, 

NIST); T. Vorburger, A. Zheng (Precision Engineering 

Division, NIST); J. Taboas, R. Tuan (NIAMS, NIH)

Biomaterials

25

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 projects are conducted in collaboration with 

partners from industrial consortia (e.g., 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 International Packaging 

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

Roadmap, the National Electronics Manufacturing Initiative (NEMI) Roadmap, the Optoelectronics Industry 

Development Association (OIDA) Roadmap, and the 

National Magnetic Data Storage Industry Consortium 

(NSIC) Roadmap. 

Contact: Christopher L. Soles
26

Dimensional Metrology with Small Angle X-Ray Scattering

The feature size in microelectronic circuitry is ever decreasing, and now approaches the scale of nanometers. 

This trend creates a need for new measurements capable 

of non-destructive measurements of small features consisting of a variety of materials (polymers, nanoporous 

thin films, metals), with sub-nanometer precision. In this 

project, we are developing small angle x-ray scattering 

for the non-destructive measurements of the pitch, linewidth, sidewall angle, average cross section, and line 

edge roughness in nanoscale patterns. Other applications of this technique in areas such as nano-rheology 

and nanofabrication are being explored. 

Wen-li Wu and Ronald L. Jones 

The demand for increasing computer speed and deceasing power consumption continues to shrink the 

dimensions of individual circuitry components toward 

the scale of nanometers. When the smallest, or “critical”, dimensions are < 40 nm, the acceptable tolerance 

will be < 1 nm. This requirement creates significant 

challenges for measurements based on electron microscopy and optical scatterometry. In addition, the 

continuing development of new materials for extreme 

ultraviolet photoresists, nanoporous low-k dielectrics, 

and metallic interconnects all require high precision 

dimensional measurements for process development and 

optimization.

sion mode. CD-SAXS has previously demonstrated 

a capability for sub-nm precision for periodicity, line 

width, sidewall angle, and height measurements. 

This year, we have extended the capabilities to better 

quantify roughness. Structures were designed with line 

edges close to a sine wave with a nominal wavelength of 

150 nm and amplitudes ranging from 20 nm to 60 nm. 

Three classes of structures were measured: (1) centerline 

roughness (CLR), where the center of mass of the line 

varies sinusoidally but the line width remains constant; 

(2) line width roughness (LWR), where the centerline follows a straight line and the line width varies as 

two opposing sine waves; and (3) line edge roughness 

(LER), where the line edges have some randomness in 

its phase angle relative to its neighbor. These controlled 

structures produced observable “satellite” diffraction 

peaks that run parallel to the main diffraction axis. The 

peak positions provide the wavelength of the roughness, while their intensity revealed the amplitude of the 

periodic component to the roughness.

Figure 2: Schematic of model line edge roughness structures 

with the top-down SEM micrograph and the resulting SAXS data.

Also this year, NIST completed installation of the 

world’s first laboratory based CD-SAXS instrument. 

This instrument is incorporates a rotating anode source 

with two different targets, advanced focusing optics, and 

a Bonse-Hart camera. The result is a flexible system 

that can address both the development of CD-SAXS 

for the semiconductor industry and advanced structural 

measurements of nanostructured materials in solution or 

in the bulk.

Contributors and Collaborators

C. Wang, D. Ho, H. Lee, C. Soles, H. Ro, V. Tirumala, E. Lin (Polymers Division, NIST); K. Choi, B. Rice, 

G. Thompson (Intel); B. Bunday (ISMI); S. Knight (Office of Microelectronics Programs, NIST); J. Villarrubia, 

A. Vladar (MEL, NIST); P. Butler (Center for Neutron 

Research, NIST); Y. Liu (SEMATECH); Q. Lin, A. 

Grill, H. Kim (IBM); K. Char, D. Yoon (Seoul National 

University); J. Watkins (U. Mass-Amherst)

Materials for Electronics

Figure 1: Schematic of the CD-SAXS geometry, showing the 

x-ray beam (solid line) in transmission through the patterned 

sample.

 To address this need, we are developing a high precision x-ray based metrology, Critical Dimension Small 

Angle X-ray Scattering (CD-SAXS). This technique is 

capable of non-destructive measurements of test patterns 

routinely used by microelectronic industries to monitor 

their fabrication process. A collimated monochromatic 

x-ray beam of sub-Ångström wavelength is used to measure the pattern dimensions on a substrate in transmis-
27

Materials for Electronics

Organic Electronics

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 photovoltaic cells. Device performance, 

stability, and function critically depend upon charge 

transport and material interaction at the interfaces of 

disparate materials. We develop measurement methods 

to characterize the electronic and interfacial structure 

of organic electronics materials with respect to processing methods, processing variables, and materials 

characteristics.

Dean M. DeLongchamp 

Organic electronic devices are projected to revolutionize new types of integrated circuits through 

new applications that take advantage of low-cost, high 

volume manufacturing, nontraditional substrates, and 

designed functionality. The current state of organic 

electronics is slowed by 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 these technological challenges. 

electrical measurements of organic semiconductor films, 

the effect of branched end-group substitutions on molecular packing, growth mechanisms of evaporated thin 

films, and the development of combinatorial methods to 

characterize materials rapidly.

Figure 2: AFM image from terraced structure of a high carrier 

mobility polythiophene thin film.

This year, significant progress was made to identify 

the molecular characteristics of newly developed, high 

carrier mobility poly(2,5-bis(3-alkylthiophen-2-yl) 

thieno[3,2-b]thiophenes). These polymers exhibit the 

highest mobility for a polymer material due to exceptional order throughout the film. Near edge x-ray 

absorption fine structure (NEXAFS), atomic force 

microscopy (AFM), ellipsometry, Fourier transform infrared (FTIR) spectroscopy, and x-ray diffraction (XRD) 

measurements were able to highlight the influence of 

substrate surface on the film morphology, to determine 

the tilt angle of the conjugated planes, and to highlight 

the importance of the side-chain packing density on the 

structure formation.

Several activities highlighted the increasing need 

for advanced measurements and materials science 

in organic electronics. A U.S. Measurement System 

Workshop was held on “Large-area Flexible Electronics and Photonics” (http://usms.nist.gov/workshops/ 

macroelectronics.htm) to determine measurement needs 

to enable this emerging technology area. Also, NIST 

staff co-chaired and contributed to the development of a 

technology roadmap for printed and organic electronics 

with iNEMI.

Contributors and Collaborators

R.J. Kline, J. Obrzut, Y. Jung, T. Psurek, B. Vogel, 

M. Fasolka, C. Chiang, E. Lin (Polymers Division, 

NIST); D. Fischer (Ceramics Division, NIST); M. Gurau, L. Richter (CSTL, NIST); D. Gundlach, C. Richter, 

O. Kirillov, (EEEL, NIST); I. McCulloch, M. Heeney 

(Merck Chemicals), L. Lucas, G. Jabbour (Arizona 

State University); M. Chabinyc, J. Northrup (PARC); A. 

Murphy, J.M.J. Frechet, P. Chang, V. Subramanian (U. 

C. Berkeley); M. Ling, Z. Bao (Stanford University); Y. 

Wu, B. Ong (Xerox); M. Toney (Stanford Synchrotron 

Radiation Laboratory)

Figure 1: Several different experimental methods (NEXAFS, 

XRD, and ellipsometry) are brought together to determine the 

structure of 20 nm films to determine correlations with device 

performance.

 Organic electronics presents different measurement 

challenges from those identified for inorganic devices. 

We are developing an integrated suite of metrologies to 

correlate device performance with the structure, properties, and chemistry of materials and interfaces. We apply 

new measurement methods to provide the data and 

insight needed for the rational and directed development 

of emerging materials and processes. Studies include 
28

Polymer Photoresists for Next–Generation Nanolithography

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-32 nm length scale, challenges arise 

because photoresists appear to be reaching their resolution limits. Unique high–spatial resolution measurements are developed to reveal limits on materials and 

processes that challenge the development of photoresists 

for next-generation sub-32 nm lithography.

Vivek M. Prabhu 

Photolithography is the driving technology used by 

the microelectronics industry to fabricate integrated 

circuits with ever decreasing sizes. This fabrication 

technology is also rapidly being adopted in emerging 

areas in 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 wave lengths of 

light requiring photoresist films less than 100 nm thick 

and dimensional control to within 2 nm. 

We work closely with industrial collaborators to 

develop 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 worked with SEMATECH to determine materials sources of line-edge roughness in 

193-nm photoresists, and with Intel Corporation to 

investigate the effect of extreme-ultraviolet (EUV) exposure on pattern resolution of model EUV photoresist 

materials. We continue to provide new insight and detail 

into the complex physico–chemical processes used in 

advanced chemically amplified photoresists. Measurement methods include x-ray and neutron reflectivity 

(XR, NR), small angle neutron scattering (SANS), 

near¬–edge x-ray absorption fine structure (NEXAFS) 

spectroscopy, solid state nuclear magnetic resonance 

(NMR), quartz crystal microbalance (QCM), infrared 

variable-angle spectroscopic ellipsometry; fluorescence 

correlation spectroscopy (FCS), and atomic force microscopy.

Figure 1: Copolymer composition effect on deprotection front 

measured by NR. Swelling and dissolution behavior of polymer 

thin films controlled by developer normality quantified by QCM. 

Evaluation of three model copolymer resists for LER for100 nm 

line/space imaged with 193 nm photolithography.

Photoresists are multi-component mixtures that 

require dispersion of additives, controlled transport 

properties during the interface formation, and controlled 

dissolution behavior. The fidelity of pattern formation relies on the materials characteristics. Hence, we 

examine the influence of copolymer compositions, 

molar mass, and photoacid generator additive size to 

determine the root causes of image quality by highlighting the polymer physics and chemistry. In addition, our 

collaborators test our hypothesis using 193 nm and EUV 

lithographic tests.

Accomplishments for this past year include quantification of the copolymer composition and quencher additives effect on photoacid-reaction diffusion deprotection 

front for resolution and roughness fundamentals by NR, 

advancement of photoresist / liquid interfaces for dissolution fundamentals by QCM, effect of exposure dose 

on the reaction-front in model EUV materials, photoacid 

generator miscibility and dispersion in complex photoresist co- and ter-polymers by NMR, aqueous immersion 

dependence on photoacid generator leeching and depth 

profile by NEXAFS, and development of cross-correlation FCS with nanopositioning for labeled-polymer 

diffusivity in bulk and at interfaces.

Contributors and Collaborators

B. Vogt, A. Rao, S. Kang, D. VanderHart, K. Lavery, W. Wu, E. Lin (Polymers Division, NIST); D. 

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

Satija (NIST Center for Neutron Research, NIST); K. 

Turnquest (SEMATECH); Kwang-Woo Choi (Intel); 

R. Allen, W. Hinsberg, H. Ito (IBM Almaden Research 

Center); R. Dammel, F. Houlihan (AZ Electronics); J. 

Sounik, M. Sheehan (DuPont Electronic Polymers)

Materials for Electronics
29

Program Overview

Nanometrology

Nanotechnology will revolutionize and possibly 

revitalize many industries, leading to new and improved 

products based on materials having at least one dimension less than 100 nm. The federal government’s role in 

realizing the full potential of nanotechnology is coordinated through the National Nanotechnology Initiative 

(NNI), a multi-agency, multi-disciplinary program that 

supports research and development, invests in a balanced infrastructure, and promotes education, knowledge diffusion, and commercialization in all aspects of 

nanoscale science, engineering, and technology. NIST’s 

unique and critical contribution to the NNI is nanometrology, defined as the science of measurement and/or a 

system of measures for nanoscale structures and systems. NIST nanometrology efforts focus on developing 

the measurement infrastructure - measurements, data, 

and standards - essential to advancing nanotechnology 

commercialization. This work provides the requisite 

metrology tools and techniques and transfers enabling 

measurement capabilities to the appropriate communities.

The NIST Materials Science and Engineering Laboratory (MSEL) plays a vital role in nanometrology work 

at NIST with efforts in four of the seven NNI Program 

Component Areas - Instrumentation Research, Metrology and Standards for Nanotechnology; Nanomaterials; Nanomanufacturing; and Fundamental Nanoscale 

Phenomena and Processes. Innovative projects across 

MSEL are defining and addressing the forefront research 

issues in these areas.

Contacts: Alamgir Karim; Kalman Migler

Carbon Nanotube Project Meeting

Polymers Division Small-Angle X-Ray Scattering Facility
30

Carbon Nanotube Materials: 

Achieving The Gold Standard in Quality and Characterization

The availability of high-quality, well-characterized 

carbon nanotube materials is essential to the development of advanced applications that exploit the 

nanotube’s remarkable combination of properties. 

Our goal is to provide the methodologies that will 

produce Gold Standard nanotubes materials separated by length, diameter, and type. These high-quality 

samples will enable characterization of their electrical, optical and mechanical properties.

Barry J. Bauer, Erik K. Hobbie 

and Kalman B. Migler 

A world-wide effort to harness the extraordinary 

properties of carbon nanotubes and to develop 

revolutionary new functional applications ranging from 

high-speed electronics to biosensors, fuel cells, and displays is underway. However, typical nanotube materials 

contain dozens of different types of tubes, have a wide 

distribution of lengths, and frequently contain impurities. The ill-defined nature of this material prevents 

proper characterization, which hampers trade and application development. 

Our goal is to enhance both the quality of nanotube 

materials and the characterization methodologies of 

them by the development of solution-based techniques 

which sort the nanotubes by type and length, and enable 

characterization on materials of high purity. We are 

currently focusing our efforts on three key areas which 

demonstrate the principles of our approach. First, we 

are developing metrics for assessing the dispersion of 

nanotubes in solutions and in polymers. Second, we are 

fractionating dispersed suspensions to produce nanotubes of well-defined length, and then characterizing 

the effects of length on their optical and toxicological 

properties. Third, we are laying the groundwork for the 

next phase of the project, using the length fractionated 

tubes to then separate by type, via combinations of flow 

and electric fields. 

The characterization of nanotube dispersion is critical to our program, as only singly dispersed nanotubes 

can be separated by length and type. Further, fundamental characterizations through optical, electrical, 

and mechanical methods are sensitive to the degree 

of dispersion. We have compared a variety of optical, viscometric, and scattering techniques to measure 

dispersion, and found that DNA-wrapped nanotubes 

disperse well in aqueous suspensions, so we have 

chosen this material for the next phase of the project. 

In the Technical Highlights section of this report, we 

describe our achievement of unprecedented dispersion 

using the DNA-wrapped nanotubes in a model polymer, 

and the resulting comparison of dispersion measurement 

techniques. 

Nanometrology

Figure 1: Absorption spectroscopy for 12 fractions that eluted from 

an ion-exchange column.

Next, we utilize the well-dispersed nanotubes for 

length fractionation through size-exclusion chromatography. We have introduced automated quality control 

measures into the chromatography via on-line viscometry and light scattering. We are exploring the effects of 

length on absorption and Raman spectroscopy, and we 

find a strong increase of absorbance with length as well 

as shifts in key Raman ratios. The well-characterized, 

length separated fractions are also being used in toxicology studies, and we find that the long SEC fractions 

show much lower toxicity. 

Finally, we are laying the groundwork to take the 

length-separated tubes and further separate them by type 

(semi-conducting vs. metallic). This requires measures 

of the response of the DNA-wrapped nanotubes to 

electric fields and the complex flow fields in a fieldflow-fractionation system. We have measured a wide 

range of electrophoretic mobilites on tubes of the same 

nominal length, and have measured the polarizability 

and impedance of the tubes in AC electrical fields. The 

data generated will drive the design of future separation 

methods.

The methods and data developed here will be utilized to 

develop standards for nanotube characterization, and to 

develop complementary reference materials.

Contributors and Collaborators

V. Bajpai, M. Becker, J. Fagan, J. Obrzut, F. Phelan 

(Polymers Division, NIST); A. Hight Walker, I. Mandelbaum, J. Simpson (PL, NIST); A. Allen, V. Hackley 

(Ceramics Division, NIST); S. Hooker, W. Johnson; 

T. Yildirum (NIST Center for Neutron Research); S. 

Arepalli (NASA); M. Pasquali (Rice U.); B. Landi, R. 

Raffaelle(RIT)
31

Industrial developers of nanomaterials strive to adapt 

combinatorial and high-throughput methods to accelerate product discovery and optimization. This project addresses the primary barrier to the application 

of these attractive measurement approaches to nanostructured polymer materials: the design of appropriate combinatorial libraries. To meet this need, we 

produce and demonstrate library designs that express 

the factors governing nanomaterials behavior, and 

that are amenable to high-throughput characterization by industrially relevant nanometrologies.

Michael J. Fasolka and Thomas H. Epps III 

The structure and performance of nanostructured polymer materials, including self-assembling systems, nanocomposites, and lithographic resists, depend 

on a plethora of interdependent compositional, interfacial, and processing factors. This makes these materials 

prime candidates for combinatorial and high-throughput 

devel-opment. However, as detailed in a 2006 NIST 

Combinatorial Methods Center (NCMC) Industry Workshop Report, adaptation of combinatorial methods to 

these systems is hampered by the persistent challenge of 

de-signing appropriate combinatorial libraries (see NISTIR 7332, www.nist.gov/combi). Specifically, industry 

requires libraries that express the parameters relevant 

to nanomaterials behavior, and that can be analyzed 

with the measurements they currently rely upon, such 

as Transmission Electron Microscopy (TEM), Atomic 

Force Microscopy (AFM), and X-Ray Photoelectron 

Spectroscopy (XPS).

The NCMC has produced a suite of gradient combinatorial library designs that are readily employed for 

the high-throughput analysis of polymer nanomaterials. 

Gradients in temperature, composition, film thickness, 

and substrate surface energy (g) provide means to rapidly and comprehensively measure the effect of these key 

factors on structure and performance. Moreover, these 

planar libraries are highly geared for characterization 

by automated microscopy and spectroscopy methods. 

In 2006, we extended gradient approaches to analyze 

triblock copolymer thin films. In bulk systems, these 

materials self-assemble into intricate nanostructures 

that can be harnessed for membranes and electronic 

devices, but it is uncertain whether these compelling 

motifs persist in the thin film geometries required for 

these applications. We demonstrated a gradient design 

to gauge the effect of g on the film behavior of a triblock 

copolymer that exhibits a unique gyroid morphology in 

the bulk. As shown in Figure 1, our library revealed that 

this material switched from its bulk morphology to a 

lamellar motif in thin films, and illuminated a critical g

(water contact angle of ≈70o) below which the material 

exhibited “autophobic dewetting.” Automated XPS and 

NEXAFS (Near Edge X-Ray Absorption Fine Structure) 

analysis along the library shows that dewetting was 

driven by a g-dependent structuring of a polymer monolayer that forms at the substrate surface. This work was 

reported via invited lectures at meetings of the American 

Physical Society and the American Chemical Society in 

2006.

Nanometrology

Also in 2006, we designed a method to prepare combinatorial libraries of film specimens for TEM analysis. 

The industrial need for this is paramount, since TEM is 

the primary tool many companies use for imaging nanostructures. As shown in Figure 2, our method employs 

an array of poly(acrylic acid) (PAA) droplets, which 

are deposited over a thin film library; in the Figure, a 

gradient library of block copolymer on silicon is shown. 

A polydimethylsiloxane (PDMS) gasket, with an array 

of holes, is used to sequester plugs of aqueous PAA 

solution while they dry atop the specimen. The system is 

then immersed in liquid nitrogen, which causes the PAA 

droplets to pull a library of 48 different film specimens 

from the substrate. Since they remain lodged in the 

gasket, the PAA plugs retain their registry. Samples are 

harvested by dissolving the PAA plugs to leave floating 

films that can be retrieved with TEM grids.

Combinatorial Methods for Nanomaterials and 

Nanometrology

Figure 1: Optical micrograph of g-dependent morphology and 

autophobic dewetting in a triblock copolymer thin film. 

Contributors and Collaborators

K. Roskov, D. DeLongchamp, A. Karim (Polymers 

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

E. Jablonski (Bucknell University); F. Bates (University 

of Minnesota) 

Figure 1: Combinatorial film libraries for TEM analysis.
32

Defects in Nanostructured Materials

The functionality of nanoscale materials, critical to 

emerging technologies in data storage, microelectronics, and medical diagnostics, is strongly dependent 

on the density and location of physical, chemical, and 

magnetic defects. Currently, a lack of tools capable 

of characterizing defects in these materials limits the 

development of these important technologies. We are 

developing measurement platforms capable of high 

precision measurements of defects in nanostructured 

surfaces, and materials to enable manufacturing at 

these scales, as well as provide insight into materials 

properties that control defect formation. 

Ronald L. Jones and Alamgir Karim 

Manufacturing reliable structures with nanometer 

scale dimensions is a potential route to advanced 

technologies for microelectronics, medial diagnostics 

and therapy, and data storage. However, manufacturing 

is challenged by the sensitivity of structural functionality to small concentrations of defects in size, shape, and 

chemical composition. Current methods of inspection 

are incapable of rapidly locating the “needle-in-ahaystack” defect until late in manufacturing stages, and 

are often destructive to the sample. We are developing 

measurement platforms capable of quantifying the type 

and number of defects, their location, and their resulting 

impact on materials properties. 

In addition to advancing manufacturing methods, 

measurement platforms to characterize defects will 

advance the fundamental understanding of defect 

formation mechanisms, providing additional control 

over material properties. Controlled defect formation in 

bulk materials has long been an important route toward 

mechanical toughening in crystals, altering phase transitions in solids, and imposing the formation of amorphous glasses.

Nanometrology

Figure 1: Transmission electron micrography of a cross 

sectioned porous silica film created by patterning with a block 

copolymer template. The image shows a wide range of structural 

irregularities (Image courtesy H.-C. Kim).

Figure 2: SAXS intensity as a function of scattering vector parallel 

(horizontal axis) and perpendicular to the substrate (vertical axis) 

for nanostructured silica films. The data shows qualitative and 

quantitative differences between varying degrees of orientational 

control, including (from left to right) randomly packed spheres, 

partially oriented cylinders, and highly oriented lamellae.

One platform under development uses small angle 

x-ray scattering (SAXS) to measure the 3D distribution 

of orientation within nanostructured thin films. In Fig. 

1, the microphase structure of a block copolymer film 

has been chemically converted to a porous silica film as 

a potential route toward high density data storage and 

next generation membranes. Controlling the orientation of the morphology is critical to both applications. 

The data in Fig. 2 demonstrates both a qualitative and 

quantitative change in SAXS intensity as the orientation 

of the microphases is varied. Fits of the data provide 

high precision measures of the distribution in orientation 

non-destructively in a manner exportable to industry. 

Other platforms being developed aim to characterize 

and quantify magnetic interactions in individual metallic nanoparticles, rapidly quantifying the concentration 

of defective particles for many applications, including 

medical diagnostics. Precise characterization of nanoparticle interactions is also aiding the development a 

“nanotagger” platform that utilizes nanoparticles to 

“seek, identify, and locate” chemical and topological defects on surfaces by attaching and fluorescing. 

Applications of these platforms focus on fundamental 

understanding of packing defects during self-assembly 

of polymer crystals and block copolymer films. 

Contributors and Collaborators

J. Benkoski, B. Berry, S. Lacerda, J. F. Douglas 

(Polymers Division, NIST); J. Pyun (University of Arizona); S. Kim, R. Briber (University of Maryland); T. 

Albrecht (Hitachi); K.-W. Choi (Intel); K.-I. Nihara, H. 

Jinnai (Kyoto Institute of Technology); H.-C. Kim (IBM 

Almaden)
33

Technologies such as next-generation electronics, 

advanced adhesives, and functional coatings depend 

on robust interfaces between a variety of hard and 

soft materials. To ensure the reliability of new products and drive these products into new and emerging 

markets, industry requires means to assess the host of 

factors that govern the mechanical behavior of these 

systems. With an emphasis on combinatorial and 

high-throughput approaches, this project develops 

and demonstrates innovative tools for measuring the 

mechanical properties and performance of materials 

systems that incorporate complex interfaces.

Christopher M. Stafford 

Adhesion between materials depends on a multitude 

of factors, including interfacial energy, interfacial 

roughness, chemical interactions, polymer entanglements, and a variety of energy dissipation mechanisms. 

Given this immense parameter space, the understanding and optimization of adhesion in a given system 

requires a huge number of experiments. In this capacity, 

combinatorial and high-throughput techniques offer a 

promising measurement solution for industrial researchers. As part of our effort to extend these revolutionary 

approaches to the mechanical analysis of systems with 

complex interfaces, in 2006 we designed a number of 

combinatorial libraries that express key factors that 

govern interfacial adhesion. These libraries are a foundation for gauging and optimizing the effect of these 

parameters. Moreover, these specimen arrays complement high-throughput measurement schemes, including 

our multilens contact adhesion test and our combinatorial edge lift-off test. 

Polymer brushes provide a facile route for expressing diverse chemistry and functionality on a surface. 

As illustrated in Figure 1, by changing monomer types, 

surface initiator site density, and reaction times across 

a surface, we are producing libraries that systematically 

express chemical moieties, chain lengths, and molecular 

architectures, which dictate polymer adhesion. These 

types of libraries also present a unique opportunity to 

study the effects of molecular rearrangements at contacting interfaces.

Roughness plays a critical role in interfacial adhesion, however systematic measurements of the effect of 

this factor are difficult to achieve. To meet this need, we 

are developing approaches to design roughness libraries 

that span multiple length scales. For example, a versatile method for creating roughness gradients exploits the 

melting and fusion of surface-adsorbed polymer microspheres. As shown in Figure 2, the scale of roughness 

is gradually varied by melting the spheres on a temperatures gradient. In addition, we are harnessing a buckling 

phenomenon to design libraries that independently vary 

the amplitude and lateral spacing of surface roughness.

Nanometrology

Mechanics of Complex Interfaces: 

Libraries for Probing Interfacial Adhesion

Development of multi-component adhesives and 

coatings by industry involves testing hundreds or 

thousands of candidate formulations. To address this 

challenge, we are developing routes to prepare compositional libraries of the viscous polymer mixtures that are 

inherent to these systems. This work is part of a NIST 

Combinatorial Methods Center (NCMC) Focus Project 

with Intel and ICI/National Starch, completed in 2006. 

These companies will use these libraries for the highthroughput optimization of epoxy underfill materials 

for flip-chip electronics. In 2007, we will develop and 

demonstrate the rapid measurement of the interfacial 

strength across these libraries using our combinatorial 

edge lift-off test.

In 2006, we reported our project achievements at 

key national conferences in the adhesion field. Invited 

lectures on this work were given at the two Gordon 

Research Conferences (Science of Adhesion, and Combinatorial and High-Throughput Material Science), the 

Adhesion Society, and the Materials Research Society. 

We also disseminated our results to industrial partners at 

semi-annual NCMC Workshop lectures.

Contributors and Collaborators

C.M. Stafford, H. Huang, X. Hu, J.H. Kim, J.Y. 

Chung, M.Y.M. Chiang, C. Xu, K.L. Beers (Polymers 

Division, NIST); R. Huang (UT Austin); Y. Dar, S. Gibbon (ICI/National Starch); N. Patel (Intel) Figure 1: Illustration of different polymer brush libraries for 

assessing interfacial adhesion.

Figure 2: Atomic force micrographs of a roughness library 

produced by melting polymer microspheres on a temperature 

gradient.
34

Nanoimprint Lithography

Nanoimprint lithography is a high-throughput patterning technique with the ability to directly replicate 

features smaller than 10 nm, not just in optimized 

resists, but also in functional materials. This makes 

the technology extremely attractive for many forms 

of nanotechnology, starting with CMOS applications, 

and extending into many emerging technologies. To 

fully harness the potential of nanoimprint lithography requires development of the measurement infrastructure to evaluate, quantify, and tailor the unique 

properties that come with patterning materials on the 

nanoscale.

Christopher L. Soles 

There are two aspects of nanoimprint lithography introducing measurement challenges. The first 

aspect is resolution. Because this technique has inherently high-resolution, basic shape metrology becomes a 

significant challenge. Quantifying physical dimensions 

is critical for evaluating patterning processes, quality 

control, and assessing the long-term stability of nanoscale features. Currently the semiconductor industry is 

challenged by with shape metrology at the 65 nm technology node. The potential jump to sub-10 nm features 

exacerbates this challenge. The second aspect stems 

from directly patterning the material of interest. This 

differs from other lithographies where a sacrificial resist 

transfers the pattern into the functional material. Beyond pattern shape, it then becomes critical to quantify 

how the desired properties of the functional material are 

impacted by the imprint process. This is a new class of 

metrology for the nanofabrication community.

Significant progress has been made on both aspects. 

Critical dimension small angle x-ray scattering (CDSAXS) and specular x-ray reflectivity (SXR) for pattern 

shape characterization were adapted for nanoimprint lithography. Papers were published describing how these 

techniques could be used to quantify, with nm precision, 

the fidelity of the imprint pattern transfer process. If the 

nanostructures are to be made of functional material, 

they must also be stable for long periods of time. Stability in nanostructures, especially polymeric ones, will be 

a major challenge for nanomanufacturing. Using CDSAXS and SXR, we found that the imprint process can 

induce internal stress that can compromise the stability 

of the resulting nanostructures. By modifying imprint 

variables, such as the time, temperature, and the molecular mass of the material being imprinted, we illustrated 

how these stresses can be minimized.

Examples of imprinted functional materials include 

semicrystalline materials where the crystal morphology 

needs to be controlled for organic semiconductor applications, and nanoporous low-k dielectric materials for 

interconnect technologies. For the patterned low-k materials, the way in which the imprint process affects the 

porosity will be important for controlling the effective k 

of the pattern. The Figure below, obtained by SXR and 

CD-SAXS, compares the imprinted pattern cross-section 

to the mold, quantifying the effects of pattern shrinkage 

upon vitrification. A modest shrinkage occurs in the 

vertical direction, with almost no shrinkage in the lateral. Knowing and controlling this shrinkage will be critical for next generation devices. The panel to the right 

further shows how the porosity of the pattern varies as a 

function of height (obtained by x-ray porosimetry). The 

porosity is reduced in the patterned region. These types 

of metrologies will be critical for developing effective 

imprint process for low-k materials

Nanometrology

This year our findings were published in high profile 

journals, including Applied Physics Letters, Nano Letters, and Physical Review Letters. Industrial outreach 

to the semiconductor industry was achieved through invited and contributed presentations at major lithography 

and metrology conferences. These included a Webcast 

for Semiconductor International that was viewed by 

thousands worldwide. Bilateral cooperative agreements 

were established and funded with Seoul National University and the Indian Institute of Technology, Kanpur.

Contributors and Collaborators

H.-J. Lee, H. Ro, Y. Ding, B. Okerberg, K. Alvine, 

R. Jones, E. Lin, A. Karim, W.-L. Wu (Polymers Division, NIST); D. Hines (University of Maryland); S. 

Pang, D. Gidley (University of Michigan) 
35

The self-assembly of molecules and nanoparticles is 

central to the formation of biological structures, and 

the synthetic emulation of this process offers great 

promise for nanometrology and nanofabrication. Accordingly, this approach to fabrication has recently 

been identified in U.S. chemical industry roadmaps 

for nanomanufacturing. We respond to this challenge 

by developing theoretical, computational, microfluidic, and optical methods to enable precision measurements of the thermodynamic and kinetic parameters 

controlling synthetic self-assembly

Jack F. Douglas and Steven D. Hudson 

Self-assembly of nanoparticles into functional structures such as sensors, optical filters, and pharmaceutical agents holds great promise for inexpensive 

manufacturing at the nanoscale. The greatest opportunity involves self-assembly of highly directional and 

specific interactions that lead to structures that have a 

chain-like, sheet-like, or shell-like structure. The basic 

design rules that describe how a given set of anisotropic 

particles assembles into a given structure are now being 

developed as one component of this project. The second 

component addresses the critical need for methods to 

measure these anisotropic and specific interactions 

between particles; such basic information is the key to 

determining how the asymmetry of interacting particles 

encodes information about the geometry of the organized structure.

Our theoretical approach to the principles governing 

this process is inspired by existing models and measurements for the self-assembly of actin, tubulin, and the 

ubiquitous icosahedral shell structures of viral capsids. 

In our simulations, we introduce a family of simple, yet 

anisotropic, potentials that give rise to the self-assembly 

of linear polymeric, random surface (“membrane”), 

tubular (“nanotube”), and hollow icosahedral structures 

that are similar in many respects to their biological 

counterparts, yet simple enough for model experimental 

realization. The potentials involve equivalent particles 

and an interplay between directional (dipolar, multipolar) and short range (van der Waals) interactions. 

Specifically, we find that the dipolar potential, having 

a continuous rotational symmetry about the dipolar 

axis, gives rise to chain formation, while particles with 

multipolar potentials having discrete rotational symmetries (square quadrupole or triangular ring of dipoles 

or “hexapole”) lead to the self-assembly of sheet (see 

Figure), nanotube, and hollow icosahedral geometries. 

These examples reveal a general design rule: the local 

rotational symmetries of the organizing particles tend 

to be preserved in the final organized structure. They 

also strongly motivate the need for methods to measure 

the anisotropic interaction strength. We also show that 

fluctuations in the assembly kinetics and the form of 

assembly and polymorphism can be controlled with 

appropriate seeding of the assembly process. Seeding is 

thus crucial to the effective control of kinetics and form 

of synthetic self-assembly.

Nanometrology

Self-Assembly for Soft Nanomanufacturing

Extensive effort has also been made in characterizing the thermodynamic nature of self-assembly, and in 

the numerical and experimental procedures required in 

determining the thermodynamic parameters governing 

these transitions. A recent commentary in Science magazine (July 7, p.55) highlights this modeling effort.

Current method and technology development here 

explores the potential of particles with charged patches 

or magnetic moments to control assembly. Surfacesensitive and patterning techniques are being adapted 

to access anisotropic interactions between particles. 

These measurements employ the asymmetry inherent at 

a surface. 

The geometry of these assemblies is characterized by 

electron microscopy, microfluidic, and optical methods. 

Recently, we have discovered hollow colloidal shell 

structures, and are working with Percec and coworkers 

to manipulate the interactions controlling this structure. 

Microfluidic traps have been used to determine interaction strength within assemblies. 

Contributors and Collaborators

T. Chastek (Polymers Division, NIST); V. Hackley 

(Ceramics Division, NIST); Y. Xia (U. Washington); 

V. Percec (U. Pennsylvania); K.F. Freed and J. Dudowicz (U. Chicago); S. Kumar (Rensselaer Polytechnic 

Institute); W. Losert (U. Maryland); S. Velankar (U. 

Pittsburgh)

Figure 1: Self-assembled sheet preserving the local symmetry of 

quadrupole particles (shown in enlargement). 
36
37

Safety and Reliability

We take for granted that the physical infrastructure 

around us will perform day in and day out with consistent reliability. Yet, failures occur when these structures 

degrade to where they no longer sustain their design 

loads, or when they experience loads outside their original design considerations. In addition, we have become 

increasingly aware of our vulnerability to intentional 

attacks. The Safety and Reliability Program within the 

NIST Materials Science and Engineering Laboratory 

(MSEL) was created to develop measurement technology to clarify the behavior of materials under extreme 

and unexpected loadings, to assess integrity and remaining life, and to disseminate guidance and tools to assess 

and reduce future vulnerabilities. Project selection is 

guided by identification and assessment of the particular 

vulnerabilities within our materials-based infrastructure, 

and focusing on those issues that would benefit strongly 

by improved measurements, standards, and materials 

data. Ultimately, our goal is 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:

• Develop advanced measurement methods needed 

by industry to address reliability problems that arise 

with the development of new materials;

• Develop and deliver standard measurements and 

data;

• Identify and address vulnerabilities and needed 

improvements in U.S. infrastructure; and

• Support other agency needs for materials expertise. 

Contact: Chad R. Snyder

Program Overview
38

Ballistic Resistance of Polymeric Materials

This project is developing metrologies and 

Failure of a first responder’s personal body armor 

prompted NIST’s Office of Law Enforcement Standards (OLES), under the auspices of the National Institute of Justice (NIJ), to initiate a program to assess 

the long-term durability and effectiveness of current 

and future soft body armor products. In response, we 

are developing metrologies and models to test and 

predict the long-term reliability of polymers used in 

these products.

Gale A. Holmes and Chad R. Snyder 

I

n a recent review [1] of the potential degradation 

mechanisms of the ballistic fiber poly (p-phenylene 

benzobisoxazole, i.e., PBO), ultraviolet (UV) radiation 

exposure, exposure to moisture, elevated temperature 

exposure, and mechanical folding have been identified as mechanisms that may compromise the structural 

integrity of the active ballistic fiber during use. Since 

answers related to the long-term durability of the armor 

are sought, any testing methodology must allow relevant 

degradation mechanisms to occur under field conditions 

and controlled exposure conditions without compromising the structural integrity of the armor. As a result the 

testing methodology must be non- or minimally-invasive, precisely determine the mechanical properties of 

the ballistic fibers, and reflect the ballistic performance 

properties of the armor.

ASTM Standard D3379-75, a statistically robust 

testing methodology that measures the tensile strength 

and Young’s modulus for high modulus single-filament 

materials that also addresses the issue of sample size, 

was modified to accurately measure the strain-to-failure 

and diameter of single filaments, with the latter providing a more accurate measure of the yield strength and 

Young’s modulus of the filament. This test was designed 

to monitor changes in fiber properties without compromising the integrity of flexible body armor. In addition 

to showing that changes in ballistic fiber properties are 

readily quantified using this test, results from PBO filaments have shown that deviations of the yield strength 

data from the expected normal distribution can be attributed to abnormal variations in the fiber diameter of 

the PBO filament along its length, thus highlighting the 

need to profile the length of the tested fiber.

Research data from 2005 indicated that a single 

severe fold in a PBO fiber could result in a greater than 

10 % reduction in ballistic performance, as quantified by 

the test method discussed above. To better quantify the 

Our research on the degradation pathways of PBO 

and PBO-like materials has focused on the role of 

residual phosphoric acid on the chemical degradation 

of these materials. A procedure was devised to extract 

residual acid using a soxhlet extractor, methylate any 

extracted phosphoric acid by diazomethane, and identify 

and quantify its presence by gas chromatography-mass 

spectrometry. This more involved procedure was devised to overcome the presence of phosphorus containing sizing material that may be added during processing. 

Initial results indicate that after a week-long extraction 

process, only 25 % of the phosphorus containing species 

was removed from the fiber. Research is ongoing to 

identify the extracted phosphorus, which is presumed 

to be composed primarily of the sizing additive, and to 

devise a more robust approach for removing the remaining phosphorus believed to be trapped in the micro and 

nanoscale voids of the fiber structure.

References

1. G. A. Holmes, K. Rice, C.R. Snyder, Journal of 

Materials Science 41, 4105 (2006).

Contributors and Collaborators

J. Kim, W.G. McDonough, W. Blair, K. Flynn, C.M. 

Guttman, W. Wallace (Polymers Division, NIST); K. Rice 

(Office of Law Enforcement Standards, NIST); J.R. Sieber 

(Analytical Chemistry Division, NIST)K. Rice (Office of 

Law Enforcement Standards, EEEL); T. Dang (Air Force 

Office of Scientific Research)

Safety and Reliability

impact of fatigue on ballistic performance, a device was 

designed (below) for use on a servo hydraulic machine, 

such as those commonly used to measure the fatigue 

resistance of structural materials, to fold single and multiple layers of woven fabric of ballistic material. Initial 

data from this device indicate that repeated folding of 

PBO fibers can result in a greater than 20 % reduction in 

ballistic performance after 5 000 cycles or seven months 

of wear! Since this is a new testing methodology, research is being conducted to validate these preliminary 

test results.
39

Polymers Division FY06 Annual Report Publication List

Polymers Division FY06 Annual Report Publication List

Polymer Science and Characterization 

Dielectric Spectroscopy

J. Obrzut, “Coaxial line reflection method for dielectric permittivity of thin film samples at microwave 

frequencies - numerical and experimental analysis,” in 

Proceedings of the 40th Annual Symposium of the International Microwave Power Institutes, 2006, Boston, 

MA.

J. Obrzut, “Measurement of Materials Dielectric 

Properties” in Handbook of Materials Measurement 

Methods edited by H. Czichos, T. Saito and L. Smith, 

(Springer, 2006).

J. Obrzut and R. Nozaki, “ TDR Permittivity Measurements Of Dielectric Films,” in Procceedings of the 

IEEE Conference on Instrumentation and Measurement. 

April 2006, Sorrento, Italy.

Anopchenko, T. Psurek, D. VanderHart, J. F. Douglas, and J. Obrzut, “Dielectric Study of the Antiplasticization of Trehalose by Glycerol,” Physical Review E 74, 

(2006).

Ballistic Resistance of Polymers

G. A. Holmes, K. Rice, and C. R. Snyder, “Ballistic 

Fibers: A Review of the Thermal, Ultraviolet and Hydrolytic Stability of the Benzoxazole Ring Structure,” 

Journal of Materials Science 41, 4105-4116 (2006). 

Polymer Mass Spectrometry

W. E. Wallace, M. A. Arnould, and R. Knochenmuss, 

“2,5-Dihydroxybenzoic Acid: Laser Desorption/Ionisation As a Function of Elevated Temperature,” International Journal of Mass Spectrometry 242, 13-22 (2005). 

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

Filliben, “Significant Parameters in the Optimization 

of MALDI-TOF-MS for Synthetic Polymers,” Journal 

of the American Society for Mass Spectrometry 17, 

246-252 (2006).

C.M. Guttman, “Mass Spectrometry,” in Encyclopedia of Polymer Science and Technology, Concise, third 

edition, edited by H. F. Mark, (Wiley, 2007).

W.E. Wallace, C.M. Guttman, K.M. Flynn, and A.J. 

Kearsley, “Development of an Absolute Molecular 

Mass Distribution Polymer Standard,” in Abstracts of 

the Third International Symposium on Separation and 

Characterization of Natural and Synthetic 

Macromolecules, Amsterdam, Netherlands (2006). 

Rheology and Processing

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

Morgan, H. Zhou, S. R. Oriani, C. W. Macosko, and K. 

B. Migler, “Coating Kinetics of Fluoropolymer Processing Aids for Sharkskin Elimination: The Role of Droplet 

Size,” Journal of Non-Newtonian Fluid Mechanics 131, 

22-31 (2005).

A.J. Bur and K. Migler, “A Multi-Sample Melt 

Micro-Rheometer,” in Proceedings Of the Annual 

Technical Meeting of the Society of Plastics Engineers 

(ANTEC), May, 2006, Charlotte, NC.

Polymer Theory

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

Glass Transition Temperature of Polymer Melts,” 

Journal of Physical Chemistry B 109, 21285-21292 

(2005).

J. Dudowicz, K. F. Freed, and J. F. Douglas, “Fragility of Glass-Forming Polymer Liquids,” Journal of 

Physical Chemistry B 109, 21350-21356 (2005).

J. Dudowicz, K. F. Freed, and J. F. Douglas, “Direct Computation of Characteristic Temperatures and 

Relaxation Times for Glass-Forming Polymer Liquids,” 

Journal of Chemical Physics 123, 111102 (2005).

B. M. Besancon, C. L. Soles, and P. F. Green, “Glass 

Transition of Miscible Binary Polymer-Polymer Thin 

Films,” Physical Review Letters 97, 057801 (2006).

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

Equilibrium Polymerization Describe the Dynamic 

Heterogeneity of Glass-Forming Liquids?” Journal of 

Chemical Physics 125, 144907 (2006).

J. Dudowicz, K. F. Freed, and J. F. Douglas, “Entropy Theory of Polymer Glass Formation Revisited. 

I. General Formulation,” Journal of Chemical Physics

124, 064901 (2006).

A. Warren, J. T. Cabral, and J. F. Douglas, “Solution 

of a Field Theory Model of Frontal Photopolymerization,” Physical Review E 72, 021801 (2005).

L. Granasy, T. Pusztai, T. Borzsosnyi, G. I. Toth, G. 

Tegze, J. A. Warren, and J. F. Douglas, “Polycrystalline 

Patterns in Far-From-Equilibrium Freezing: a Phase 

Field Study,” Philosophical Magazine 86, 3757-3778 

(2006).
40

L. Granasy, T. Pusztai, T. Borzsonyi, G. Toth, G. 

Tegze, J. A. Warren, and J. F. Douglas, “Phase Field 

Theory of Crystal Nucleation and Polyerystalline 

Growth: A Review,” Journal of Materials Research 21, 

309-319 (2006).

JL. Granasy, T. Pusztai, G. Tegze, J. A. Warren, and 

J. F. Douglas, “Growth and Form of Spherulites,” 

Physical Review E 72, 011605 (2005).

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

“Lattice Model of Equilibrium Polymerization. V. Scattering Properties and the Width of the Critical Regime 

for Phase Separation,” Journal of Chemical Physics

124, 144906 (2006).

R. A. Riggleman, K. Yoshimoto, J. F. Douglas, and J. 

J. de Pablo, “Influence of Confinement on the Fragility 

of Antiplasticized and Pure Polymer Films,” Physical 

Review Letters 97, 045502 (2006).

S. K. Kumar, G. Szamel, and J. F. Douglas, “Nature 

of the Breakdown in the Stokes-Einstein Relationship in 

a Hard Sphere Fluid,” Journal of Chemical Physics 124, 

214501 (2006).

H. Zhang, D. J. Srolovitz, J. F. Douglas, and J. A. 

Warren, “Characterization of Atomic Motion Governing Grain Boundary Migration,” Physical Review B 74, 

115404 (2006).

Biomaterials

Metrology for Biomechanical Effects on Cell-Material 

Interactions

L.M. Pakstis, L.A. Henderson, and J.P. Dunkers, 

“Physical and Biological Characterization of Protein 

Modified Biomaterial Surfaces,” in Proceedings of the 

New Jersey Center for Biomaterials 8th Annual 

Biomaterials Symposium, 2006, New Brunswick, NJ.

K. M. N. Oates, W. E. Krause, R. L. Jones, and R. 

H. Colby, “Rheopexy of Synovial Fluid and Protein 

Aggregation,” Journal of the Royal Society Interface 3, 

167-174 (2006).

Metrology for 3D Scaffold Characterization

K. Zhang, N. R. Washburn, J. M. Antonucci, and C. 

G. Simon, “In Vitro Culture of Osteoblasts With Three 

Dimensionally Ordered Macroporous Sol-Gel Bioactive 

Glass (3DOM-BG) Particles,” Bioceramics 17, 655-658 

(2005).

S. Lin-Gibson, R. L. Jones, N. R. Washburn, and F. 

Horkay, “Structure-Property Relationships of Photopolymerizable Poly(Ethylene Glycol) Dimethacrylate 

Hydrogels,” Macromolecules 38, 2897-2902 (2005).

S. Lin-Gibson, S. Bencherif, J. M. Antonucci, R. L. 

Jones, and F. Horkay, “Synthesis and Characterization 

of Poly(Ethylene Glycol) Dimethacrylate Hydrogels,” 

Macromolecular Symposia 227, 243-254 (2005).

T. W. Kee and M. T. Cicerone, “Biological Imaging 

Using Broadband Coherent Anti-Stokes Raman Scattering (CARS) Microscopy,” Biophysical Journal 88, 362A 

(2005).

N. P. Patel, M. A. Hunt, S. Lin-Gibson, S. Bencherif, 

and R. J. Spontak, “Tunable CO2 Transport Through 

Mixed Polyether Membranes,” Journal of Membrane 

Science 251, 51-57 (2005).

M. Y. M. Chiang, X. F. Wang, F. A. Landis, J. Dunkers, and C. R. Snyder, “Quantifying the Directional 

Parameter of Structural Anisotropy in Porous Media,” 

Tissue Engineering 12, 1597-1606 (2006).

J.P. Dunkers, J.G. Hagedorn, A. Peskin, J.T. Kelso, 

and J.E. Terrill, “Quantitative, Interactive Measurement 

of Tissue Engineering Scaffold Structure Using Immersive Visualization,” in Proceedings of the 8th NJ 

Symposium on Biomaterials, New Brunswick, NJ 

(2006).

J.P. Dunkers, J.G. Hagedorn, A. Peskin, J.T. Kelso, 

J.E. Terrill, and L. Henderson, “Interactive, Quantitative 

Analysis Of Scaffold Structure Using Immersive Visualization,” in Proceedings of BIO2006, Amelia Island, FL 

(2006).

J.P. Dunkers, S.D. Leigh, M.T. Cicerone, and L. 

Henderson, “Quantifying The Structure Of Candidate 

Geometric Reference Scaffolds,” in Regenerate 2006, 

Pittsburgh, PA (2006).

T. Dutta Roy, J.S. Stephens, A. Rege, M.T. Cicerone, 

J. Kohn, and M.L. Becker, “Osteoblast Response on 

Tyrosine-Derived Polycarbonate Tissue Engineering 

Scaffolds,” in Biophysical Journal, New Brunswick, NJ 

(2006).

T. Dutta Roy, J.J. Stone, W. Sun, E.H. Cho, S.J. 

Lockett, F.W. Wang, and L. Henderson, “Colocalization 

Of Cell Adhesion Proteins On 3D Tissue Engineering 

Scaffolds Fabricated By Rapid Prototyping,” in 

Transactions of the Society for Biomaterials 31st Annual 

Meeting and Exposition, 2006, Pittsburgh, PA .

T. Dutta Roy, J.J. Stone, W. Sun, E.H. Cho, S.J. 

Lockett, F.W. Wang, and L. Henderson, “Expression Of 

Osteoblast Adhesion Proteins On 3D Rapid Prototyped 

Scaffolds,” in Transactions of the 52nd Annual Meeting 

of the Orthopaedic Research Society, Chicago, IL.

Polymers Division FY06 Annual Report Publication List
41

J. A. Cooper, L. O. Bailey, J. N. Carter, C. E. Castiglioni, M. D. Kofron, F. K. Ko, and C. T. Laurencin, 

“Evaluation of the Anterior Cruciate Ligament, Medial 

Collateral Ligament, Achilles Tendon and Patellar Tendon As Cell Sources for Tissue-Engineered Ligament,” 

Biomaterials 27, 2747-2754 (2006).

T. W. Kee, H. X. Zhao, and M. T. Cicerone, “OneLaser Interferometric Broadband Coherent Anti-Stokes 

Raman Scattering,” Optics Express 14, 3631-3640 

(2006).

Y. Hotta, K. Komatsu, and F.W. Wang, “Cure Monitoring Of Hydrosilation-Curable Silicones By Fluorescence Spectroscopy,” in Proceedings of Society For 

Biomaterials 31st Annual Meeting, 2006, Pittsburgh.

F. A. Landis, J. S. Stephens, J. A. Cooper, M. T. 

Cicerone, and S. Lin-Gibson, “Tissue Engineering Scaffolds Based on Photocured Dimethacrylate Polymers 

for in Vitro Optical Imaging,” Biomacromolecules 7, 

1751-1757 (2006).

C. T. Laurencin, Y. Khan, M. Kofron, S. El-Amin, E. 

Botchwey, X. J. Yu, and J. A. Cooper, “Tissue Engineering of Bone and Ligament - A 15-Year Perspective,” 

Clinical Orthopaedics and Related Research 221-236 

(2006).

W. J. Li, J. A. Cooper, R. L. Mauck, and R. S. Tuan, 

“Fabrication and Characterization of Six Electrospun 

Poly(Alpha-Hydroxy Ester)-Based Fibrous Scaffolds for 

Tissue Engineering Applications,” Acta Biomaterialia 2, 

377-385 (2006).

S. Lin-Gibson, F. A. Landis, and C. M. Stafford, “Polymerization Shrinkage Measurements of PhotocrossLinked Dimethacrylate Films,” Abstracts of Papers of 

the American Chemical Society 231 (2006).

S. Lin-Gibson, F. A. Landis, and P. L. Drzal, “Combinatorial Investigation of the Structure-Properties 

Characterization of Photopolymerized Dimethacrylate 

Networks,” Biomaterials 27, 1711-1717 (2006).

Metrology for Dental Materials

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

K. Xu, and W. G. McDonough, “Chemistry of Silanes: 

Interfaces in Dental Polymers and Composites,” Journal 

of Research of the National Institute of Standards and 

Technology 110, 541-558 (2005).

E. A. Wilder and J. M. Antonucci, “Improved 

Dental Composites Utilizing Dibenzylidene Sorbitol 

Networks,” Macromolecular Symposia 227, 255-263 

(2005).

D. Skrtic, S. Y. Lee, J. M. Antonucci, and D. W. 

Liu, “Amorphous Calcium Phosphate Based Polymeric 

Composites: Effects of Polymer Composition and 

Filler’s Particle Size on Composite Properties,” 

Bioceramics 17, 737-740 (2005).

Dundigalla, S. Lin-Gibson, V. Ferreiro, M. M. Malwitz, and G. Schmidt, “Unusual Multilayered Structures 

in Poly(Ethylene Oxide)/Laponite Nanocomposite 

Films,” Macromolecular Rapid Communications 26, 

143-149 (2005).

J. M. Antonucci and D. Skrtic, “Matrix Resin Effects 

on Selected Physicochemical Properties of Amorphous 

Calcium Phosphate Composites,” Journal of Bioactive 

and Compatible Polymers 20, 29-49 (2005).

J. Antonucci, T. B. Icenogle, W. F. Regnault, D. W. 

Liu, J. N. R. O’Donnell, and D. Skrtic, “Polymerization 

Shrinkage and Stress Development in Bioactive Urethane Acrylic Resin Composites,” Abstracts of Papers of 

the American Chemical Society 231 (2006).

E. F. Burguera, H. H. K. Xu, and M. D. Weir, “Injectable and Rapid-Setting Calcium Phosphate Bone 

Cement With Dicalcium Phosphate Dihydrate,” Journal 

of Biomedical Materials Research Part B-Applied 

Biomaterials 77B, 126-134 (2006).

N. Eidelman, N. Tsutsumi, and C. K. Chiang, “Micro 

FTIR Mapping of Nanometer Ferroelectric Polymer 

Films,” Macromolecular Rapid Communications 27, 

558-562 (2006).

M. Farahani, W. E. Wallace, J. M. Antonucci, and 

C. M. Guttman, “Analysis by Mass Spectrometry of the 

Hydrolysis/Condensation Reaction of a Trialkoxysilane 

in Various Dental Monomer Solutions,” Journal of 

Applied Polymer Science 99, 1842-1847 (2006).

W.F. Regnault, T.B. Icenogle, J.M. Antonucci, D.W. 

Liu, and D. Skrtic, “Structure/Property Relationships In 

Urethane Dimethacrylate-Based Acp Composites,” in 

Proceedings of the 2006 Annual Meeting of the Society 

for Biomaterials, Pittsburgh, PA.

J. N. R. O’Donnell, D. Skrtic, and J. M. Antonucci, 

“Amorphous Calcium Phosphate Composites With 

Improved Mechanical Properties,” Journal of Bioactive 

and Compatible Polymers 21, 169-184 (2006).

D. Skrtic, J. M. Antonucci, and D. W. Liu, “Ethoxylated Bisphenol Dimethacrylate-Based Amorphous 

Calcium Phosphate Composites,” Acta Biomaterialia 2, 

85-94 (2006).

F. W. Wang and R. E. Lowry, “Wavelength-Shift 

Fluorescent Probes for Monitoring of Polymerization,” 

Journal of Applied Polymer Science 101, 747-750 

(2006).

Polymers Division FY06 Annual Report Publication List
42

M. D. Weir, H. H. K. Xu, and C. G. Simon, “Strong 

Calcium Phosphate Cement-Chitosan-Mesh Construct 

Containing Cell-Encapsulating Hydrogel Beads for 

Bone Tissue Engineering,” Journal of Biomedical 

Materials Research Part A 77A, 487-496 (2006).

K. S. Wilson and J. M. Antonucci, “Interphase 

Structure-Property Relationships in Thermoset Dimethacrylate Nanocomposites,” Dental Materials 22, 

995-1001 (2006).

H. H. K. Xu, L. Sun, M. D. Weir, J. M. Antonucci, 

S. Takagi, L. C. Chow, and M. Peltz, “Nano DCPAWhisker Composites With High Strength and Ca and 

PO4 Release,” Journal of Dental Research 85, 722-727 

(2006).

H. H. K. Xu, M. D. Weir, E. F. Burguera, and A. M. 

Fraser, “Injectable and Macroporous Calcium Phosphate 

Cement Scaffold,” Biomaterials 27, 4279-4287 (2006).

Combinatorial Methods for Tissue Engineering

Y. Mei, T. Wu, C. Xu, K. J. Langenbach, J. T. Elliott, 

B. D. Vogt, K. L. Beers, E. J. Amis, and N. R. Washburn, “Tuning Cell Adhesion on Gradient Poly(2-Hydroxyethyl Methacrylate)-Grafted Surfaces,” Langmuir

21, 12309-12314 (2005).

C. G. Simon, N. Eidelman, S. B. Kennedy, A. 

Sehgal, C. A. Khatri, and N. R. Washburn, “Combinatorial Screening of Cell Proliferation on Poly(D,L-Lactic 

Acid)/Poly(D,L-Lactic Acid) Blends,” Biomaterials 26, 

6906-6915 (2005).

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: Synthesis, 

Surface Analysis, and Cell Response in Vitro,” Polymer 

Biocatalysis and Biomaterials 900, 343-353 (2005).

L. O. Bailey, S. Lipplatt, F. S. Biancanello, S. D. 

Ridder, and N. R. Washburn, “The Quantification of 

Cellular Viability and Inflammatory Response to Stainless Steel Alloys,” Biomaterials 26, 5296-5302 (2005).

C. G. Simon, J. M. Antonucci, D. W. Liu, and D. 

Skptic, “In Vitro Cytotoxicity of Amorphous Calcium 

Phosphate Composites,” Journal of Bioactive and 

Compatible Polymers 20, 279-295 (2005).

K. Loo, S. B. Kennedy, N. Eidelman, Y. Tai, M. 

Zharnikov, E. J. Amis, A. Ulman, and R. A. Gross, 

“Combinatorial Approach to Study Enzyme/Surface 

Interactions,” Langmuir 21, 5237-5241 (2005).

B. Hammouda, F. Horkay, and M. L. Becker, “Clustering and Solvation in Poly(Acrylic Acid) Polyelectrolyte Solutions,” Macromolecules 38, 2019-2021 (2005).

Y. M. An, J. W. Cooper, B. M. Balgley, and C. S. 

Lee, “Selective Enrichment and Ultrasensitive Identification of Trace Peptides in Proteome Analysis Using 

Transient Capillary Isotachophoresis/Zone Electrophoresis Coupled With Nano-ESI-MS,” Electrophoresis 27, 

3599-3608 (2006).

M. L. Becker, N. D. Gallant, and E. J. Amis, “A Universal Substrate for Bio-Functionalization,” Abstracts of 

Papers of the American Chemical Society 231 (2006).

M. L. Becker, M. J. Joralemon, and K. L. Wooley, 

“Nanoparticles Decorated for Development As Synthetic Vaccines,” Abstracts of Papers of the American 

Chemical Society 231 (2006).

C.G. Simon Jr, “Combinatorial Polymer Scaffold 

Library,” in PTEI Regenerate 2006 World Congress on 

Tissue Engineering and Regenerative Medicine, Pittsburgh, PA.

Y. Yang, M.L. Becker, J. Kohn, and J.C.G. Simon, “Polymeric Combinatorial Scaffold Libraries 

for Screening Cell-Biomaterial Interactions,” in 2006 

International Microelectronics and Packaging Society 

Conference Proceeding, Chicago, IL.

S. B. Kennedy, N. R. Washburn, C. G. Simon, and E. 

J. Amis, “Combinatorial Screen of the Effect of Surface 

Energy on Fibronectin-Mediated Osteoblast Adhesion, Spreading and Proliferation,” Biomaterials 27, 

3817-3824 (2006).

Y. Mei, J. T. Elliott, J. R. Smith, K. J. Langenbach, T. 

Wu, C. Xu, K. L. Beers, E. J. Amis, and L. Henderson, 

“Gradient Substrate Assembly for Quantifying Cellular 

Response to Biomaterials,” Journal of Biomedical Materials Research Part A 79A, 974-988 (2006).

L. O. Bailey, M. L. Becker, J. S. Stephens, N. D. 

Gallant, C. M. Mahoney, N. R. Washburn, A. Rege, J. 

Kohn, and E. J. Amis, “Cellular Response to PhaseSeparated Blends of Tyrosine-Derived Polycarbonates,” 

Journal of Biomedical Materials Research Part A 76A, 

491-502 (2006).

L. O. Bailey, M. D. Weir, and N. R. Washburn, 

“Quantification of Macrophage Viability and Inflammatory Response to Dental Bonding Resins,” Journal of 

Bioactive and Compatible Polymers 21, 185-206 (2006).

Polymers Division FY06 Annual Report Publication List
43

Combinatorial Methods 

(also see Combinatorial Methods for Tissue 

Engineering)

NIST Combinatorial Methods Center

C.M. Stafford, K. E. Roskov, T. H. Epps, and M. 

J. Fasolka, “Generating Thickness Gradients of Thin 

Polymer Films Via Flow Coating,” Review of Scientific 

Instruments 77, 023908 (2006)

M.J. Fasolka, “Experimental Approaches From A 

“Forward Looking” Laboratory: Polymer And Coatings 

Research At The NIST Combinatorial Methods Center,” 

in Proceedings of the 33rd International Waterborne, 

High-Solids, and Powder Coatings Symposium, New 

Orleans, LA (2006).

I. Takeuchi, J. Lauterbach, M. J. Fasolka, “Combinatorial materials synthesis,” Materials Today 8, 18-26, 

(2005).

Polymer Formulations

C. Xu, T. Wu, Y. Mei, C. M. Drain, J. D. Batteas, and 

K. L. Beers, “Synthesis and Characterization of Tapered 

Copolymer Brushes Via Surface-Initiated Atom Transfer 

Radical Copolymerization,” Langmuir 21, 11136-11140 

(2005).

S. Rathgeber, T. Pakula, A. Wilk, K. Matyjaszewski, and K. L. Beers, “On the Shape of Bottle-Brush 

Macromolecules: Systematic Variation of Architectural 

Parameters,” Journal of Chemical Physics 122, 124904 

(2005). 

E. J. Amis, K. L. Beers, and S. D. Hudson, “High 

Throughput Approaches to Analysis of Complex Mixtures,” Abstracts of Papers of the American Chemical 

Society 231 (2006).

S. E. Barnes, Z. T. Cygan, J. K. Yates, K. L. Beers, 

and E. J. Amis, “Raman Spectroscopic Monitoring of 

Droplet Polymerization in a Microfluidic Device,” 

Analyst 131, 1027-1033 (2006).

I. Norman, W. H. Zhang, K. L. Beers, and E. J. Amis, 

“Microfluidic Light Scattering As a Tool to Study the 

Structure of Aqueous Polymer Solutions,” Journal of 

Colloid and Interface Science 299, 580-588 (2006).

I. Norman, D. L. Ho, J. H. Lee, and A. Karim, 

“Spontaneous Formation of Vesicles of Diblock Copolymer EO6BO11 in Water: A SANS Study,” Journal of 

Physical Chemistry B 110, 62-67 (2006).

S. Rathgeber, T. Pakula, A. Wilk, K. Matyjaszewski, H. I. Lee, and K. L. Beers, “Bottle-Brush Macromolecules in Solution: Comparison Between Results 

Obtained From Scattering Experiments and Computer 

Simulations,” Polymer 47, 7318-7327 (2006).

Xu, T. Wu, and K. L. Beers, “Patterned Polymer 

Brushes From Surface-Initiated Polymerization Inside 

a Microchannel,” Abstracts of Papers of the American 

Chemical Society 231, 308 (2006). 

C. Xu, S. E. Barnes, T. Wu, D. A. Fischer, D. M. 

DeLongchamp, J. D. Batteas, and K. L. Beers, “Solution 

and Surface Composition Gradients Via Microfluidic 

Confinement: Fabrication of a Statistical-CopolymerBrush Composition Gradient,” Advanced Materials 18, 

1427-1430 (2006).

C. Xu, T. Wu, C. M. Drain, J. D. Batteas, M. J. 

Fasolka, and K. L. Beers, “Effect of Block Length on 

Solvent Response of Block Copolymer Brushes: Combinatorial Study With Block Copolymer Brush Gradients,” 

Macromolecules 39, 3359-3364 (2006).

C. Xu, T. Wu, J. D. Batteas, C. M. Drain, K. L. 

Beers, and M. J. Fasolka, “Surface-Grafted Block Copolymer Gradients: Effect of Block Length on Solvent 

Response,” Applied Surface Science 252, 2529-2534 

(2006).

K.L. Beers, “Controlled Radical Polymerization In 

Confined Spaces,” in 4th IUPAC Sponsored Symposium 

on Radical Polymerization: Kinetics and Mechanism, Il 

Ciocco, Italy. (2006) 

C. Xu and K.L. Beers, “Gradient Libraries Of 

Surface-Grafted Polymers: Combinatorial Tools For 

Surface Functionality,” Proceedings Of the Annual 

Technical Meeting of the Society of Plastics Engineers 

(ANTEC), Charlotte, NC, (2006).

Mechanics of Complex Interfaces

C. M. Stafford, B. D. Vogt, C. Harrison, D. Julthongpiput, and R. Huang, “Elastic Moduli of Ultrathin 

Amorphous Polymer Films,” Macromolecules 39, 

5095-5099 (2006). 

E. A. Wilder, S. Guo, S. Lin-Gibson, M. J. Fasolka, 

and C. M. Stafford, “Measuring the Modulus of Soft 

Polymer Networks Via a Buckling-Based Metrology,” 

Macromolecules 39, 4138-4143 (2006). 

H. Huang, X. Hu, C. Xu, K.L. Beers, and C.M. 

Stafford, “Construction Of Combinatorial Libraries To 

Study Adhesion In A Multilens Measurement Platform,” 

in Adhesion Society Annual Meeting - Extended 

Abstracts, 2006, Jacksonville, FL.

Polymers Division FY06 Annual Report Publication List
44

R. Huang, C.M. Stafford, and B.D. Vogt, “Wrinkling 

of ultrathin polymer films,” in MRS Proceedings, 2006, 

San Francisco, CA.

J.H. Kim, M.Y. Chiang, D. Kawaguchi, G. Royston, and C.M. Stafford, “Estimation Of The Interfacial 

Adhesion Strength In Compositional Libraries Of Epoxy 

Films,” in Adhesion Society Annual Meeting - Extended 

Abstracts, 2006, Jacksonville, FL.

P.M. McGuiggan and J. Filliben, “High Throughput 

Measurement of Peel of A Pressure Sensitive Adhesive,” 

in Pressure Sensitive Tape Council Proceedings, Las 

Vegas (2006). 

C.M. Stafford, “Application Of Combinatorial Methods For The Testing of Adhesives,” in MII Technical 

Conference & Review, 2006, Virginia Tech, Blacksburg, 

VA.

C.M. Stafford, J.H. Kim, D. Kawaguchi, G. Royston, 

and M.Y. Chiang, “Probing The Interfacial Adhesion 

Strength In Compositional Libraries Of Epoxy Films,” 

in MRS Proceedings, 2006, Boston, MA.

C.M. Stafford, H.W. Ro, R.L. Jones, M.J. Fasolka, 

and C.L. Soles, “High-Throughput Screening of Adhesion and Release in Nanoimprint Lithography,” in 

Adhesion Society Annual Meeting - Extended Abstracts, 

2006, Jacksonville, FL.

P. M. McGuiggan, A. Chiche, F. Phelan, M. Fasolka, J. Filliben, and D. J. Yarusso, High Throughput 

Measurement of Peel of A Pressure Sensitive Adhesive. 

Adhesives and Sealants Industry Magazine April 2006, 

32-39 (2006).

C.M. Stafford and C. Harrison, “Elastic Moduli of 

Polymer Thin Films: A High-throughput Metrology”, 

in Encyclopedia of Materials: Science and Technology, 2006 Online Update. Editors: Buschow, Flemings, 

Cahn, Veyssière, Kramer, and Mahajan (Elsevier, 2006).

Nanotechnology

Thin Films

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,” Applications of Scanned Probe Microscopy to 

Polymers 897, 65-84 (2005).

D. C. Hurley, A. Kopycinska-Muller, D. Julthongpiput, and M. J. Fasolka, “Influence of Surface Energy 

and Relative Humidity on AFM Nanomechanical Contact Stiffness,” Applied Surface Science 253, 1274-1281 

(2006).

P. M. McGuiggan and J. S. Wallace, “Maximum 

Force Technique for the Measurement of the Surface 

Tension of a Small Droplet by AFM,” Journal of 

Adhesion 82, 997-1011 (2006).

K. A. Page, F. A. Landis, A. K. Phillips, and R. B. 

Moore, “SAXS Analysis of the Thermal Relaxation of 

Anisotropic Morphologies in Oriented Nafion Membranes,” Macromolecules 39, 3939-3946 (2006).

R. Jones, S. Kim, A. Karim, R. M. Briber, and H. C. 

Kim, “Orientation of Block Copolymer Phases Within 

Confined Environments,” Abstracts of Papers of the 

American Chemical Society 231 (2006).

K. M. Ashley, D. Raghavan, J. F. Douglas, and A. 

Karim, “Wetting-Dewetting Transition Line in Thin 

Polymer Films,” Langmuir 21, 9518-9523 (2005).

P. Achalla, J. McCormick, T. Hodge, C. Moreland, P. 

Esnault, A. Karim, and D. Raghavan, “Characterization 

of Elastomeric Blends by Atomic Force Microscopy,” 

Journal of Polymer Science Part B-Polymer Physics 44, 

492-503 (2006).

S. K. Satija, A. Karim, and J. Duangrut, “Tuning 

Interface Potential for Block Copolymer Thin Film Ordering,” Abstracts of Papers of the American Chemical 

Society 231 (2006).

C. Soles, “X-Ray Reflectivity As an Effective 

Interface Metrology for Nanotechnology,” Abstracts of 

Papers of the American Chemical Society 231 (2006).

Karim, J. Douglas, K. Ashley, and D. Raghavan, 

“Dewetting Transition in Thin Polymer Films,” 

Proceedings Of the Annual Technical Meeting of the 

Society of Plastics Engineers (ANTEC), 2006, Charlotte, 

NC.

Composites

S. Balakrishnan, P. R. Start, D. Raghavan, and S. D. 

Hudson, “The Influence of Clay and Elastomer Concentration on the Morphology and Fracture Energy of 

Preformed Acrylic Rubber Dispersed Clay Filled Epoxy 

Nanocomposites,” Polymer 46, 11255-11262 (2005).

T. Kashiwagi, F. M. Du, J. F. Douglas, K. I. Winey, 

R. H. Harris, and J. R. Shields, “Nanoparticle Networks 

Reduce the Flammability of Polymer Nanocomposites,” 

Nature Materials 4, 928-933 (2005).

J. Bur, Y. H. Lee, S. C. Roth, and P. R. Start, “Measuring the Extent of Exfoliation in Polymer/Clay 

Nanocomposites Using Real-Time Process Monitoring 

Methods,” Polymer 46, 10908-10918 (2005).

Polymers Division FY06 Annual Report Publication List
45

T. Koga, C. Li, Y. Sun, A. Brazin, M. H. Rafailovich, 

J. C. Sokolov, J. F. Douglas, and D. Mahajan, “Surface 

Modification of Polymeric Nanocomposite Thin Films 

Using Supercritical Carbon Dioxide,” Topics in 

Catalysis 32, 257-262 (2005).

E. J. Garboczi, J. F. Douglas, and R. B. Bohn, “A Hybrid Finite Element-Analytical Method for Determining 

the Intrinsic Elastic Moduli of Particles Having Moderately Extended Shapes and a Wide Range of Elastic 

Properties,” Mechanics of Materials 38, 786-800 (2006).

J. H. Kim, G. A. Holmes, and C. R. Snyder, “A 

Methodology for Detecting Interfacial Debonding in 

Clay/Epoxy Nanocomposites,” Journal of Adhesion 

Science and Technology 20, 1079-1089 (2006).

C. K. Moon, G. A. Holmes, and W. G. McDonough, 

“Study on the Interfacial Properties of Two-Dimensionally Arranged Glass Fiber/Epoxy Resin Model Composites,” Journal of Applied Polymer Science 99, 1541-1551 

(2006).

Nanotubes

E. K. Hobbie, B. J. Bauer, J. Stephens, M. L. Becker, 

P. McGuiggan, S. D. Hudson, and H. Wang, “Colloidal 

Particles Coated and Stabilized by DNA-Wrapped Carbon Nanotubes,” Langmuir 21, 10284-10287 (2005).

B. J. Bauer, E. K. Hobbie, and M. L. Becker, “SmallAngle Neutron Scattering From Labeled Single-Wall 

Carbon Nanotubes,” Macromolecules 39, 2637-2642 

(2006).

J. A. Fagan, B. J. Landi, I. Mandelbaum, J. R. Simpson, V. Bajpai, B. J. Bauer, K. Migler, A. R. H. Walker, 

R. Raffaelle, and E. K. Hobbie, “Comparative Measures 

of Single-Wall Carbon Nanotube Dispersion,” Journal 

of Physical Chemistry B 110, 23801-23805 (2006).

D. Fry, B. Langhorst, H. Wang, M. L. Becker, B. J. 

Bauer, E. A. Grulke, and E. K. Hobbie, “Rheo-Optical 

Studies of Carbon Nanotube Suspensions,” Journal of 

Chemical Physics 124, 054703 (2006).

E. K. Hobbie, J. Obrzut, S. B. Kharchenko, and E. 

A. Grulke, “Charge Transport in Melt-Dispersed Carbon 

Nanotubes,” Journal of Chemical Physics 125, 044712 

(2006).

F.R. Phelan Jr. and B.J. Bauer, “Simulation of Rodlike Particles in Field-Flow Fractionation (FFF),” in 

Proceedings of the 2006 AICHE Annual Meeting, San 

Francisco, CA.

B.J. Bauer, V. Bajpai, J.A. Fagan, M.L. Becker, and 

K. Hobbie Erik, “Chromatographic Separation of Single 

Wall Carbon Nanotubes,” in MRS, Spring 2006, San 

Francisco, CA.

Organic Electronics

D. M. DeLongehamp, B. D. Vogt, C. M. Brooks, 

K. Kano, J. Obrzut, C. A. Richter, O. A. Kirillov, and 

E. K. Lin, “Influence of a Water Rinse on the Structure and Properties of Poly(3,4-Ethylene Dioxythiophene): Poly(Styrene Sulfonate) Films,” Langmuir 21, 

11480-11483 (2005).

D. M. DeLongchamp, B. M. Vogel, Y. Jung, M. C. 

Gurau, C. A. Richter, O. A. Kirillov, J. Obrzut, D. A. 

Fischer, S. Sambasivan, L. J. Richter, and E. K. Lin, 

“Variations in Semiconducting Polymer Microstructure 

and Hole Mobility With Spin-Coating Speed,” 

Chemistry of Materials 17, 5610-5612 (2005).

A. R. Murphy, P. C. Chang, P. VanDyke, J. S. Liu, J. 

M. J. Frechet, V. Subramanian, D. M. DeLongchamp, 

S. Sambasivan, D. A. Fischer, and E. K. Lin, “SelfAssembly, Molecular Ordering, and Charge Mobility in 

Solution-Processed Ultrathin Oligothiophene Films,” 

Chemistry of Materials 17, 6033-6041 (2005).

N. Tsutsumi, A. Ueyasu, W. Sakai, and C. K. 

Chiang, “Crystalline Structures and Ferroelectric Properties of Ultrathin Films of Vinylidene Fluoride and 

Trifluoroethylene Copolymer,” Thin Solid Films 483, 

340-345 (2005).

M. L. Chabinyc, F. Endicott, B. D. Vogt, D. M. 

DeLongchamp, E. K. Lin, Y. L. Wu, P. Liu, and B. 

S. Ong, “Effects of Humidity on Unencapsulated 

Poly(Thiophene) Thin-Film Transistors,” Applied 

Physics Letters 88, 113514 (2006).

D. M. DeLongchamp, M. M. Ling, Y. Jung, D. 

A. Fischer, M. E. Roberts, E. K. Lin, and Z. N. Bao, 

“Thickness Dependence of Microstructure in Semiconducting Films of an Oligofluorene Derivative,” Journal 

of the American Chemical Society 128, 16579-16586 

(2006).

D. M. DeLongchamp, D. A. Fischer, B. M. Vogel, 

R. J. Kline, Y. Jung, M. Gurau, L. J. Richter, and E. 

K. Lin, “Near-Edge X-Ray Absorption Fine Structure 

Spectroscopy As a Characterization Tool for Organic 

Semiconductors,” Abstracts of Papers of the American 

Chemical Society 231 (2006).

E. K. Lin, “Developing Metrology to Enable the Realization of Organic Electronics Devices,” Abstracts of 

Papers of the American Chemical Society 231 (2006).

J. Obrzut, “Nonlinear Charge Transport in Semiconducting Polythiophene,” Abstracts of Papers of the 

American Chemical Society 231 (2006).

Polymers Division FY06 Annual Report Publication List
46

Z. D. Schultz, M. Gurau, D. M. DeLongchamp, 

B. M. Vogel, R. J. Kline, Y. Jung, E. K. Lin, and L. J. 

Richter, “Nonlinear Spectroscopic Characterization of 

Polymer Thin Films,” Abstracts of Papers of the 

American Chemical Society 231 (2006).

D.M. DeLongchamp, E.K. Lin, and D.A. Fischer , 

“Organic Semiconductor Structure and Chemistry from 

Near-edge X-ray Absorption Fine Structure (NEXAFS) 

Spectroscopy,” in Organic Thin Film Transistors, (Taylor & Francis, 2006).

R. Hamilton, C. Bailey, W. Duffy, M. Heeney, M. 

Shkunov, D. Sparrowe, S. Tierney, I. McCulloch, R.J. 

Kline, D.M. DeLongchamp, and M. Chabinyc, “The 

influence of molecular weight on the microstructure and 

thin film transistor characteristics of pBTTT polymers,” 

in Proceedings of the SPIE, Vol. 6336, San Diego, CA 

(2006).

R.J. Kline and M.D. McGehee, “Charge Transport 

And Morphology In Conjugated Polymers” in 

Handbook of Organic Electronics and Photonics edited 

by H.S. Nalwa (American Scientific Publishers, 2006).

Polymers for Next Generation Lithography

V. M. Prabhu, B. D. Vogt, W. L. Wu, J. F. Douglas, E. K. Lin, S. K. Satija, D. L. Goldfarb, and H. Ito, 

“Direct Measurement of the Counterion Distribution 

Within Swollen Polyelectrolyte Films,” Langmuir 21, 

6647-6651 (2005).

B. D. Vogt, R. A. Pai, H. J. Lee, R. C. Hedden, C. L. 

Soles, W. L. Wu, E. K. Lin, B. J. Bauer, and J. J. Watkins, “Characterization of Ordered Mesoporous Silica 

Films Using Small-Angle Neutron Scattering and X-Ray 

Porosimetry,” Chemistry of Materials 17, 1398-1408 

(2005).

X. F. Hua, M. S. Kuo, G. S. Oehrlein, P. Lazzeri, E. 

Iacob, M. Anderle, C. K. Inoki, T. S. Kuan, P. Jiang, and 

W. L. Wu, “Damage of Ultralow k Materials During 

Photoresist Mask Stripping Process,” Journal of Vacuum 

Science & Technology B 24, 1238-1247 (2006).

S. H. Kang, V. M. Prabhu, B. D. Vogt, E. K. Lin, 

W. L. Wu, and K. Turnquest, “Effect of Copolymer 

Composition on Acid-Catalyzed Deprotection Reaction 

Kinetics in Model Photoresists,” Polymer 47, 6293-6302 

(2006).

E. K. Lin, V. M. Prabhu, B. D. Vogt, S. H. Kang, A. 

Rao, S. K. Satija, W. L. Wu, and K. Turnquest, “Measurements Towards the Materials Sources of Line-Edge 

Roughness in Chemically Amplified Photoresists,” 

Abstracts of Papers of the American Chemical Society 

231 (2006).

V. M. Prabhu, S. Sambasivan, D. Fischer, L. K. Sundberg, and R. D. Allen, “Quantitative Depth Profiling of 

Photoacid Generators in Photoresist Materials by NearEdge X-Ray Absorption Fine Structure Spectroscopy,” 

Applied Surface Science 253, 1010-1014 (2006).

Rao, S. H. Kang, B. D. Vogt, V. M. Prabhu, E. K. 

Lin, W. L. Wu, and M. Muthukumar, “Effect of Deprotection Extent on Swelling and Dissolution Regimes 

of Thin Polymer Films,” Langmuir 22, 10009-10015 

(2006).

B. D. Vogt, S. Kang, V. M. Prabhu, E. K. Lin, S. K. 

Satija, K. Turnquest, and W. L. Wu, “Measurements 

of the Reaction-Diffusion Front of Model Chemically 

Amplified Photoresists With Varying Photoacid Size,” 

Macromolecules 39, 8311-8317 (2006).

S. Kang, V.M. Prabhu, B.D. Vogt, E.K. Lin, W. Wu, 

and K. Turnquest, “Copolymer Fraction Effect On Acid 

Catalyzed Deprotection Reaction Kinetics In Model 193 

Nm Photoresists,” in Proceedings of the SPIE Advances 

in Resist Materials and Processing XXIII, San Jose, CA 

(2006).

S. Kang, V.M. Prabhu, B.D. Vogt, E.K. Lin, W. Wu, 

and K. Turnquest, “Effect of copolymer composition on 

acid catalyzed deprotection reaction kinetics in model 

photoresists,” in Proceedings of the SPIE Advances in 

Resist Materials and Processing XXIII, San Jose, CA 

(2006).

K.A. Lavery, K.-W. Choi, B.D. Vogt, V.M. Prabhu, 

E.K. Lin, W. Wu, S. Satija, M.J. Leeson, H.B. Cao, G. 

Thompson, H. Ding, and D.S. Fryer, “Fundamentals Of 

The Reaction-Diffusion Process In Model Euv Photoresists,” in Proceedings of the SPIE Advances in Resist 

Materials and Processing XXIII, San Jose, CA (2006).

Rao, S. Kang, B.D. Vogt, V.M. Prabhu, E.K. Lin, 

W. Wu, K. Turnquest, and W.D. Hinsberg, “Dissolution 

Fundamentals Of 193nm Methacrylate Based Photoresists,” in Proceedings of the SPIE Advances in Resist 

Materials and Processing XXIII, San Jose, CA (2006).

B.D. Vogt, S. Kang, V.M. Prabhu, A. Rao, E.K. Lin, 

S.K. Satija, K. Turnquest, and W. Wu, “The Deprotection Reaction Front Profile For Model 193 Nm Methacrylate-Based Chemically Amplified Photoresists,” in 

Proceedings of the SPIE Advances in Resist Materials 

and Processing XXIII, San Jose, CA (2006).

Metrology for Nanoimprint Lithography

R. L. Jones, T. J. Hu, C. L. Soles, E. K. Lin, R. M. 

Reano, and S. M. Casa, “Real-Time Shape Evolution of 

Nanoimprinted Polymer Structures During Thermal Annealing,” Nano Letters 6, 1723-1728 (2006).

Polymers Division FY06 Annual Report Publication List
47

Polymers Division FY06 Annual Report Publication List

C. Soles, H. W. Ro, Y. F. Ding, R. L. Jones, D. Hines, 

E. K. Lin, and A. Karim, “Stability and Processing Induced Residual Stress in Imprinted Polymer Nanostructures,” Abstracts of Papers of the American Chemical 

Society 231 (2006).

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

Reano, S. W. Pang, S. J. Weigand, D. T. Keane, and J. 

P. Quintana, “Pattern Fidelity in Nanoimprinted Films 

Using Critical Dimension Small Angle X-Ray Scattering,” Journal of Microlithography Microfabrication and 

Microsystems 5, 013001 (2006).

H.-J. Lee, C.L. Soles, H.W. Ro, D.R. Hines, R.L. 

Jones, E.K. Lin, A. Karim, and W. Wu, “Characterizing 

Nanoimprint Pattern Cross Section And Fidelity From 

X-Ray Reflectivity,” in Proceedings of the SPIE 

Microlithography, San Jose, CA (2006).

H. J. Lee, H. W. Ro, C. L. Soles, R. L. Jones, E. K. 

Lin, W. L. Wu, and D. R. Hines, “Effect of Initial Resist 

Thickness on Residual Layer Thickness of Nanoimprinted Structures,” Journal of Vacuum Science & 

Technology B 23, 3023-3027 (2005).

H. J. Lee, C. L. Soles, H. W. Ro, R. L. Jones, E. K. 

Lin, W. L. Wu, and D. R. Hines, “Nanoimprint Pattern 

Transfer Quality From Specular X-Ray Reflectivity,” 

Applied Physics Letters 87, 263111 (2005).

Directed Assembly and Nanomanufacturing

K. Van Workum and J. F. Douglas, “Schematic Models of Molecular Self-Organization,” Macromolecular 

Symposia 227, 1-15 (2005).

J. F. Douglas and K. Van Workum, “Symmetry, 

Equivalence and Molecular Self-Organization,” 

Abstracts of Papers of the American Chemical Society

229, U724-U725 (2005).

K. Van Workum and J. F. Douglas, “Equilibrium 

Polymerization in the Stockmayer Fluid As a Model of 

Supermolecular Self-Organization,” Physical Review E

71, 031502 (2005).

S. D. Hudson, J. T. Cabral, W. J. Goodrum, K. L. 

Beers, and E. J. Amis, “Microfluidic Interfacial Tensiometry,” Applied Physics Letters 87, 081905 (2005).

J. T. Cabral and S. D. Hudson, “Microfluidic Approach for Rapid Multicomponent Interfacial Tensiometry,” Lab on A Chip 6, 427-436 (2006).

J. A. Pathak and S. D. Hudson, “Rheo-Optics of 

Equilibrium Polymer Solutions: Wormlike Micelles in 

Elongational Flow in a Microfluidic Cross-Slot,” 

Macromolecules 39, 8782-8792 (2006).

P. R. Start, S. D. Hudson, E. K. Hobble, and K. B. 

Migler, “Breakup of Carbon Nanotube Flocs in Microfluidic Traps,” Journal of Colloid and Interface Science

297, 631-636 (2006).

P. A. Stone, S. D. Hudson, P. Dalhaimer, D. E. Discher, E. J. Amis, and K. B. Migler, “Dynamics of Wormlike Micelles in Elongational Flows,” Macromolecules

39, 7144-7148 (2006).

K. Van Workum and J. F. Douglas, “Symmetry, 

Equivalence, and Molecular Self-Assembly,” Physical 

Review E 73, 031502 (2006).

J. Stambaugh, K. Van Workum, J. F. Douglas, and W. 

Losert, “Polymerization Transitions in Two-Dimensional Systems of Dipolar Spheres,” Physical Review E 72, 

031301 (2005).

J. J. Benkoski, R. L. Jones, J. F. Douglas, and A. 

Karim, “Competition of Forces Driving Assembly in 

Nanoscale Building Blocks,” Abstracts of Papers of the 

American Chemical Society 231 (2006).

J. J. Benkoski, H. Hu, and A. Karim, “Generation 

of Hierarchical Topologies From Photocrosslinkable, 

Particle-Stabilized Emulsions,” Macromolecular Rapid 

Communications 27, 1212-1216 (2006).

Dimensional Metrology of Nanoscale Patterns

M. S. Silverstein, M. Shach-Caplan, B. J. Bauer, R. 

C. Hedden, H. J. Lee, and B. G. Landes, “Nanopore Formation in a Polyphenylene Low-k Dielectric,” 

Macromolecules 38, 4301-4310 (2005).

S. Knight, R. Dixson, R. L. Jones, E. K. Lin, N. G. 

Orji, R. Silver, J. S. Villarrubia, A. E. Vladar, and W. L. 

Wu, “Advanced Metrology Needs for Nanoelectronics 

Lithography,” Comptes Rendus Physique 7, 931-941 

(2006).

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

K. Lin, and W. L. Wu, “Structural Characteristics of 

Methylsilsesquioxane Based Porous Low-k Thin Films 

Fabricated With Increasing Cross-Linked Particle Porogen Loading,” Journal of Applied Physics 100, 064104 

(2006).

E. K. Lin, “Advancing Nanofabrication With Small 

Angle Scattering and Reflectivity Measurements,” Abstracts of Papers of the American Chemical Society 231

(2006).

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

Lee, and B. G. Landes, “SANS and XRR Porosimetry 

of a Polyphenylene Low-k Dielectric,” Macromolecules

39, 2998-3006 (2006).
48

R.L. Jones, C. Wang, E.K. Lin, W. Wu, K. Choi, B.J. 

Rice, G.M. Thompson, S.J. Weigand, and D.T. Keane, 

“Characterization Of Line Edge Roughness Using CDSAXS,” in Proceedings of the SPIE Microlithography, 

San Jose, CA (2006).

V.R. Tirumala, B.D. Vogt, E.K. Lin, and J.J. Watkins, “Influence of Strongly Interacting Additives on the 

Long-range Order in Semi-crystalline Block Copolymer 

Templates,” in American Chemical Society Polymer 

Preprints 2006, San Francisco, CA (2006).

Polymers Division FY06 Annual Report Publication List
49

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

NIST Fellow

Wen-li Wu

Phone: 301–975–6839

E-mail: wen-li.wu@nist.gov

Group Leaders

Characterization and Measurement 

Chad R. Snyder 

Electronics Materials

Eric K. Lin

Phone: 301–975–6743

E-mail: eric.lin@nist.gov

Biomaterials

Marcus T. Cicerone

Phone: 301–975–8104

E-mail: marcus.cicerone@nist.gov

Multiphase Materials

Alamgir Karim

Phone: 301–975–6588

E-mail: alamgir.karim@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
50

Research Staff

Alvine, Kyle*

kyle.alvine@nist.gov

X-ray reflectivity & GISAXS nanostructures

Nanoparticle self-assembly 

Small angle x-ray scattering

Nanoimprint lithography

Surface tension of nanostructures

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

Antonucci, Joseph M.

joseph.antonucci@nist.gov

Synthetic polymer chemistry

Dental composites, cements and adhesion

Initiator systems

Interfacial coupling agents

Remineralizing polymer systems

Nanocomposites

Barnes, Susan E. +

susan.barnes@nist.gov

Combinatorial and high-throughput methods

Vibrational spectroscopy of polymers

Microfluidics technology

Fluorescence spectroscopy

On-line monitoring of polymer melts/extrusion

Bauer, Barry J.

barry.bauer@nist.gov

Polymer synthesis

Polymer chromatography

MALDI mass spectroscopy

Thermal characterization

Neutron, x-ray and light scattering

Dendrimers, metallic ions nanocluster

Porous low-k thin film characterization

Carbon nanotubes

Becker, Matthew L.

matt.becker@nist.gov

Polymer synthesis

Block copolymers

Peptide synthesis

Phage display

Combinatorial methods

Polymerase Chain Reaction

Beers, Kathryn L.

kathryn.beers@nist.gov

Combinatorial and high-throughput methods 

Polymer formulations

Microfluidics technology

Polymer synthesis

Controlled/living polymerizations

Berry, Brian+

brian.berry@nist.gov

Inorganic nanoparticle synthesis

Thin film zone-annealing methods

Defects in nanostructured films

Block copolymer films

Combinatorial surface modification

Neutron reflectivity and small angle scattering

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

Carey, Clifton M.*

clifton.carey@nist.gov

Dental plaque

Microanalytical analysis techniques

Fluoride efficacy for dental health

De- and re-mineralization

Phosphate chemistry

Ion-selective electrodes

Toothpaste abrasion & erosion

Cherng, Maria* 

maria.cherng@nist.gov 

Calcium phosphate biomaterials

Research Staff
51

Chastek, Thomas Q.

thomas.chastek@nist.gov

Combinatorial and high-throughput methods

Optics and fiber optics

Optical microscopy

Liquid chromatography

Microfluidics

Small angle x-ray scattering

Chastek, Thuy T.+

thuy.chastek@nist.gov

Synthetic hybrid nanocomposites

Solid state synthesis

Electron microscopy

Rheology of nanocomposites and gels

Wide and small angle x-ray diffraction

Self-assembly & lithiography

Microfluidics

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

Choi, Kwang-Woo+

kwang-woo.choi@nist.gov

Polymers for lithography 

Critical dimension small angle x-ray scattering 

 (CD-SAXS)

Extreme ultraviolet (EUV) lithography

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

Chung, Jun Young+

junyoung.chung@nist.gov

Combinatorial and high-throughput methods

Mechanics of complex interfaces

Stress relaxation and aging in thin polymer films 

Adhesion and fracture at soft interfaces

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

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

Ding, Yifu+

yifu.ding@nist.gov

Polymer dynamics

Glass transition and glass properties

Inelastic light and neutron scattering

Nanoimprint lithography 

Douglas, Jack F. 

jack.douglas@nist.gov 

Theory on polymer solutions, blends, and 

nanoparticle filled polymer materials

Physics of polymers films

Dynamics and thermodynamics of self-assembly

Crystallization of polymers

Defects and ordering in block copolymer films

Nanoparticle characterization and interactions

Research Staff
52

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

Dutta Roy, Tithi

tithi.duttaroy@nist.gov

Reference scaffolds for tissue engineering

Cellular response to biomaterials

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

Appplication of temperature and UV gradients to 

 polymers

Epps, Thomas H., III

thomas.epps@nist.gov

Combinatorial and high-throughput methods

Block copolymers

Self-assembled structures

Surface energy patterning and control

Surfaces and interfaces

Scanning probe microscopy

Fagan, Jeffrey A.

jeffrey.fagan@nist.gov

Dielectrophoretic separations

Colloidal solutions

Electrooptical effects

Carbon nanotubes

Fasolka, Michael J. 

michael.fasolka@nist.gov 

Combinatorial and high-throughput methods 

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

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

Gallant, Nathan D.

nathan.gallant@nist.gov

Cell adhesion to biomaterials

Combinatorial screening of bioactive gradients

Genson, Kirsten L.

kirsten.genson@nist.gov

Highly branched polymers

Surface initiated polymerization

Surface functionalization

Atomic force microscopy

Gradient combinatorial methods

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

Guo, Shu+

shu.guo@nist.gov

Solid mechanics

Mechanical properties of thin films

Combinatorial and high-throughput methods

Polymer thin films

Surfaces and interfaces

Research Staff
53

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

Henderson, Lori A.

lori.henderson@nist.gov

Structure-property relationships of biomaterials

Structure-function of tissues

Molecular engineering of DNA and proteins

Cellular physiology and assays

Molecular biology screening

Polymer synthesis and characterization

Ho, Derek H+

dereklho@nist.gov

Small angle neutron scattering

Small angle X-ray scattering

Clay-polymer nanocomposites

Hobbie, Erik K.

erik.hobbie@nist.gov

Light scattering and optical microscopy

Dynamics of complex fluids

Shear-induced structures in polymer blends and 

 solutions

Carbon nanotubes suspensions and melts

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

Hu, Xuesong+

xuesong.hu@nist.gov

Combinatorial Informatics

Instrument automation

Adhesion and mechanical properties

Huang, Heqing+

heqing.huang@nist.gov

Combinatorial and high-throughput methods

Adhesion and mechanical properties

Surface initiated polymerization

Polymer brushes

Hudson, Steven D.

steven.hudson@nist.gov

Electron and optical microscopy

Microfluidics

 Nanoparticle characterization and assembly

Self-assembly

Bio- and interfacial dynamics

Iida, Kazunori+

kazunori.iida@nist.gov

Combinatorial and high-throughput methods

Microfluidics and microreactors

Controlled radical polymerization

Living radical polymerization

Johnson, Jerainne

jerainne.johnson@nist.gov

Spectroscopy, fluorescence upconversion and 

time resolved fluorescence

Bench top method for evaluating materials for 

 protein storage

Jones, Ronald L.

ronald.jones@nist.gov

Neutron and x-ray scattering

Defects in nanomaterials

Neutron reflectivity

3-D tomography

Polymer surfaces and thin films

Polymer phase transitions and computer 

 simulation

Julthongpiput, Duangrut+

duangrut.julthongpiput@nist.gov

Combinatorial and high-throughput methods 

Surface energy patterning and control

Scanning probe microscopy

Jung, Youngsuk+

youngsuk.jung@nist.gov

Organic electronics

Polymer thin films and interfaces

Kang, Shuhui+

skang@nist.gov

Fourier transform infrared spectroscopy (FTIR)

Raman spectroscopy

Polymers for lithography

Polymer thin films 

Research Staff
54

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

Kee, Tak+

tak.kee@nist.gov

Ultrafast spectroscopy

Coherent anti-Stokes Raman scattering (CARS) 

 microscopy

Tissue engineering scaffolds

Confocal microscopy

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

Polymer adhesion and mechanical properties

Polymer composites

Optical coherence microscopy

Kim, Sangcheol

sangcheol.kim@nist.gov

Ordering and defects in thin nanostrucutered 

 materials

Combinatorial and high-throughput methods

AFM and optical microscopy

X-ray reflectivity

Kipper, Matthew+

matthew.kipper@nist.gov

Hemotactic, chemotactic response to 

 biomaterials

Craniofacial tissue engineering

Cell migration

Kline, R. Joseph

rjkline@nist.gov

Organic electronics

Grazing incidence x-ray diffraction

Polymer thin films morphology

AFM characterization

Lacerda, Silvia+

silvia.lacerda@nist.gov

Quantum dots synthesis and surface 

 functionalization

Quantum dot-based biosensors 

Cell-penetrating proteins and peptides for 

 delivery of nanoparticles in living cells

Interaction of nanoparticles with animal tissues

Transmission Electron Microscopy, 3D 

 tomography

Defects in block copolymer films

Assembling of particles in nanoporous 

 membranes

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

Laumeier, Carol E.

carol.laumeier@nist.gov

NIST Combinatorial Methods Center

Outreach Coordinator

Lavery, Kristopher A.

klavery@nist.gov

Polymer thin films and interfaces

Neutron and X-ray reflectometry

Off-specular reflectivity

Photoresist materials

Diblock copolymer thin films

Lee, Hae-Jeong+

hae-jeong.lee@nist.gov

X-ray reflectivity

Small-angle neutron scattering

Nanoimprint lithography

Structural characterization of low dielectric 

constant thin films

Porosimetry of porous thin films

Metrology for characterizing physical structures 

 of nanopatterns

Lin, Eric K.

eric.lin@nist.gov

Polymer thin films and interfaces

Polymer photoresists for lithography

Organic electronics 

Nanoimprint lithography

Small angle X-ray and neutron scattering

Statistical mechanics

X-ray and neutron reflectivity

Research Staff
55

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 and 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

Lucas, Leah A.+

leah.lucas@nist.gov

Organic electronics

Combinatorial methods

Surface functionalization

Markovic, Milenko*

milenko.markovic@nist.gov

Calcium phosphate chemistry

Biomineralization (normal and pathological)

Crystal growth and dissolution kinetics

Heterogeneous equilibria

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

Meillon, Mathurin+

mathurin.meillon@nist.gov

Polymer rheology

Characterization of processing aids

Migler, Kalman

kalman.migler@nist.gov

Rheology

Carbon nanotubes

 Liquid crystals

 Polymer blends

Polymer slippage

Sharkskin and extrusion

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

Okerberg, Brian C.

brian.okerberg@nist.gov

Polymer crystallization and morphology

Thin films and polymer blends

Hot-stage atomic force microscopy

Nanoimprint lithography

Optical and electron microscopy

Page, Kirt A.

kirt.page@nist.gov

X-ray scattering

Neutron scattering

Polymer structure and dynamics

Polymer brushes

Polymer Ionomers

Membranes

Combinatorial methods

Pakstis, Lisa

lisa.pakstis@nist.gov

Self-assembly of amphiphilic diblock copoly- 

 peptides 

Biomaterial-cell interactions

Physical characterization of polymer/biomaterial 

 assemblies

Microscopy, scattering, rheology, spectroscopy, 

 cell culture

Park, Jung J.+

jungjin.park@nist.gov

Microfluidics

Bioadhesion properties of nanoparticles

Biopolymer interactions

Parry, Edward E.*

edward.parry@nist.gov

Dental appliance and crown and bridges 

 fabrication

Machine shop applications

Research Staff
56

Pathak, Jai A.+

jai.pathak@nist.gov

Rheology and linear viscoelasticity

Polymer dynamics and complex fluids

Microfluidics

Patton, Derek L.

derek.patton@nist.gov

Combinatorial and high-throughput methods

Polymer brushes 

Controlled radical polymerization 

Surface functionalization 

Atomic force microscopy

X-ray Photoelectron Spectroscopy

Phelan, Jr., Frederick R.

frederick.phelan@nist.gov

Composites processing

Microfluidics

Viscoelastic flow modeling

Chaotic mixing

Flow in porous media

Lattice Boltzmann methods

Prabhu, Vivek M.

vivek.prabhu@nist.gov

Small-angle neutron scattering

Polyelectrolytes

Polymers for lithography

Fluorescence correlation spectroscopy

Polymer thin films

X-ray and neutron reflectivity

Psurek Tatiana+

tatiana.psurek@nist.gov

Dielectric spectroscopy

Organic Electronics

Polymer thin films

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

Rao, Ashwin B. +

ashwin@nist.gov

Polymer adsorption 

Thin films gels 

Fluorescence microscopy

Interfacial rheology 

Ro, Hyun Wook+

hyun.ro@nist.gov

Nanoimprint lithography 

Low-k dielectric thin films

X-ray reflectivity

Sambasivan, Sharadha+

sharadha@bnl.gov

Near-edge x-ray absorption fine structure 

 spectroscopy (NEXAFS)

Polymers for lithography

Polymer relaxation and tribology

Self assembled monolayer orientation

Catalyst surface and bulk characterization

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

Smith, Jack R.

jack.smith@nist.gov

Surface science

Computational modeling

Biomaterials characterization

Snyder, Chad R.

chad.snyder@nist.gov

Dielectric relaxation spectroscopy

Thermodynamics and kinetics of polymer 

 crystallization

Calorimetry

Thermal properties at the nanoscale

Ballistic resistance of polymers

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

Research Staff
57

Stafford, Christopher M.

chris.stafford@nist.gov

Combinatorial and high-throughput methods

Polymer thin films

Polymer adhesion

Mechanical properties of thin films

Surfaces and interfaces

Sun, Limin*

lsun@nist.gov

Macroporous biomaterials

Fiber-matrix interfacial shear strength

CPC composites

Taboas, Juan M.+

juan.taboas@nist.gov

Biomedical engineering

Cell and tissue mechanics

Mechanoactive bioreactors

Tissue engineering

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

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

Tirumala, Vijay.+

vijay.tirumala@nist.gov

Small angle neutron scattering

Block copolymer thin films

Hydrogels

Double network hydrogels

Tominaga, Taiki.+

taiki.tominaga@nist.gov

Small angle neutron scattering

Hydrogels

Double network hydrogels

Tung, Ming S.*

ming.tung@nist.gov

Chemistry of calcium phosphate and peroxide 

 compounds

Remineralization studies

Standard reference materials

Research Staff

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

Organic electronics 

Polymer thin films 

Self assembled monolayers

X-ray scattering

Solution NMR

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

Polymers for lithography

Quartz crystal microbalance

Ordered mesoporous materials

Organic electronics

Wallace, William E.

william.wallace@nist.gov

Mass spectrometry

Geometric data analysis methods

Wang, Francis W.

francis.wang@nist.gov

Photophysics and photochemistry of polymers

Fluorescence spectroscopy

Cure monitoring of polymerization

Tissue engineering

Wang, Chengqing+

chengw@nist.gov

Small angle x-ray scattering

Critical Dimension metrology

Light scattering

Polymer and colloidal solutions
58

Weir, Michael*

michael.weir@nist.gov

Biomaterials

Tissue engineering

Degradable hydrogels

Growth factor dynamics and cellular response in 

 biomaterials

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

Combinatorial and high-throughput methods

Polymer formulations

Polymer synthesis

Interfacial tension measurements

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

Zhao, Hongxia (Jessica)+

jessica.zhao@nist.gov

Computed fluid dynamics

Data acquisition

Multivariate analysis

Signal processing

* Research Associate

+ Guest Scientist

Research Staff
59

National Institute of Standards and Technology

Materials Science and Engineering Laboratory

Organizational Charts
60

Polymers Division (854.00)

Organizational Charts