# Presentation: 227028

## Interfacial Processing and Thermodynamics Program

**Chemical, Bioengineering, Environmental, and  Transport Systems (CBET)**

**Interfacial Processing and Thermodynamics Program**

**Robert (Bob) M. Wellek,**
** ****Program Director,  rwellek@nsf.gov**

** ****Interfacial Phenomena**
** ****Mass Transport**
** ****Solution Thermodynamics**

## Advanced Materials Processing

Directed- and Self-Molecular Assembly of novel Surfactant-Based Films,Structures, & Composites
Use of Bio-molecular Interfaces

Nano-materials for Sensors and other Functional Materials
Polymer Micro- and Nanostructures 

Nanotechnology & Bioprocessing

“Converging Technologies”

***Overall Program ***_***RESEARCH FOCUS & TRENDS***_

**Advanced Materials Processing**
**Directed- and Self-Molecular Assembly of novel Surfactant-Based Films,Structures, & Composites**
**Use of Bio-molecular Interfaces**
**Nano-materials for Sensors and other Functional Materials**
**Polymer Micro- and Nanostructures**
**Nanotechnology & Bioprocessing**
**“****Converging Technologies”**

##  Functional Micro & Nano-Structures and Materials

 Molecular Assembly in Solution

 Bio-related Functional Surfaces

 Polymer & Other Materials    Processing--Thin Polymer Films and Coatings

****** ****Molecular Assembly in Solution**
****** ****Bio-related Functional Surfaces**
****** ****Polymer & Other Materials    Processing--Thin Polymer Films and Coatings**

**INTERFACIAL PHENOMENA**

***Emphasis Areas:***

- Examples follow:

## Programming Chemical Molecular Assembly 

**in Space and Time for Complex Micro-geometries**** **
**CAREER Grant to:  *****Bartosz A. ******Grzybowski******, Northwestern University***

**3D open-lattice crystals**

**Structures  in semiconductor crystals**

**        ****   ****CTS / 1414 / Robert Wellek**

**** **Spontaneous molecular assembly and **
**    ****chemical reactions**** as a fundamentally novel**
**    ****    ****approach **** ****to the fabrication of small-scale**
**    ****    ****structures, **** ****devices, and detection systems.**
**** **Research success to date:**** **** enables **
**    ****    ****molecular self-organization of otherwise **
**    ****    ****hard-to-make **** ****micro- and nano-scopic devices.**
**** **Future importance:****  Allows building 2D **
**    ****    ****and 3D micro-structures that are hard (or**
**    ****     ****impossible) to make with current**
**    ****     ****technologies.  Method **** ****reduces costs of **
**    ****     ****fabrication by ~2 orders of **** ****magnitude (as**
**    ****    ****compared with photo-**** ****lithography, **
**    ****     ****ion-etching, etc.)**

##     NER: Simulation Strategies for Biomolecular  

**    ****Assembly of Nanoscale Building Blocks**

***Sharon C. Glotzer******  -  University of Michigan***

- CTS – 0210551-NER

_**Background**_**:**
**  ****DNA - the *****digital polymer***** - has unique potential as**
**    **_**assembler of nanoscale building blocks**_**:**
**    ****(1)  “****Lock and key recognition” of complementary ****	****oligonucleotides allows  **_**programmable assembly**_**.**
**    ****(2)  Tightly controlled synthesis of specific sequences allows ****	****for  high degree of **_**specificity**_**. **
**    ****(3)  Thermo-reversible nature of hybridization allows ****	**_**tunability of resulting structures**_**. **
**  ****Simulation is needed to elucidate **_***fundamental principles***_** of **
**    ****DNA-directed assembly and predict possible one-, two- and **
**    ****three-dimensional structures and how to attain them.**
_**Results**_**:**
**  ****Simulation methods**** - **_**New strategies to bridge multiple**_
**    **_**length and time scales involved in hierarchical directed **_
**    **_**assembly process.**_
**  ****Analysis algorithm**** – ****Developed efficient algorithm to**
**    ****analyze complex structure and topology of formed**
**    ****assemblies for **_**use with lattice and continuum simulation**_
**    **_**codes.**_

## Cholesterol (Nano)Domains 

**Cholesterol (Nano)Domains **
**in Biological Membranes**

**Steve Wrenn**
***Drexel University***

- CTS–0346638-CAREER

_**Background:**_

-  _**Cholesterol crystals**_** are precursors to **_**gallstones**_** and   **
**  ****are a major component in **_**atherosclerotic plaques**_
** ****The **_**mechanism of cholesterol nucleation is unknown**_
** ****Cholesterol **_**organizes  within phospholipid membranes**_
**  ****   **_**into “nano-domains**_**” -- which are likely sites of nucleation**
**  ****   ****(upper right)**

_**Results:**_

** ****Fluorescence assay used to study nano-domains**
**  **
** ****Nano-domains are detected by a restriction of energy transfer **
**  ****between a fluorescent analog of cholesterol - red - and  **
**  ****a Dasnylated phospholipid - D - (upper right)**
** **
** ****Mathematical model reveals **_**domain sizes are nominally **_
**  **_**10 nm**_**, based on the energy transfer measurements**
** ****Accuracy and sensitivity are assessed by simulating domain**
**  ****formation (of known sizes) in a lattice model (lower right).**

**simulated nanodomains**

**~10 nm**

## MASS TRANSPORT

**Diffusion Transport in Supercritical Fluids**
**Biomedical Materials **(with other programs)
**Diffusion along / at Interfaces**
**Molecular Modeling & Simulation**
_**Examples Follow:**_
**Membranes, Polymer **(with other programs)

***Emphasis Areas******:***

## Responsive Tethered Polymer Layers: Protein

_**Adsorption**_**, Phase transitions and Interactions**

***Igal Szleifer******  ******-  Purdue University***

_**Background**_**:**
**  ****Tuning the properties of tethered polymer **
**     ****layers yields:**
**     ****(1)  Manipulation of surface interactions **
**           **** ****with environment,**
**     ****(2)  Controls protein adsorption/desorption,**
** **
**     ****(3)  Stability of nanoparticles**
**     ****(4)  Ability to change pH over nanometer**
**           ****  ****scales**** **
_**Results**_**:**
**  ****Stabilization of single wall **_***carbon nano-***_
***    ***_***tubes***_** in solution**
**  ****Quantitative description of **_**protein**_
**    **_**adsorption isotherms on surfaces with **_
**    **_**grafted polymers**_
**  ****Quantitative description of polyacid grafted**
**    ****layers (structure and charge state)**
**  ****Control of the kinetics of adsorption and**
**    ****desorption on polymer modified electrodes**

-                                                                                                                                                                                       CTS–0338377

## Dimension-dependent Properties 

**of Nanoscopic Macromolecular Structures**

- CTS 0210588 NANO

-    ** ****Investigating the **_**mechanical properties**_** of **_**soft-matter**_** advanced materials: **_**nano-patterned thin films**_** **
**and nano-structured **_**polymeric **_**systems**
**    ****Seeks fundamental relationship between the **_**dynamics and transport**_** of **_**small molecules**_** in nanoscopic **_**polymer**_** films**

**Paul Nealey**
**Franco Cerrina**
**Mark Ediger**
**Juan De Pablo****University of Wisconsin**

**Nanoscale Interdisciplinary Research Team (NIRT)**

**Molecular Simulation of Nano-polymeric Structure**

**INDUSTRIAL PARTNER: INTEL**

## Protein Interactions with Nano-Scale Controlled Surfaces: 

**Protein Interactions with Nano-Scale Controlled Surfaces: **
**The Molecular Basis for Non-fouling Behavior**

**  ****Shaoyi Jiang**
**  ****University of Washington, Seattle**

**Demonstrating the importance of nano-scale structure (or OEG surface density) to the non-fouling behavior of a surface**

_***Background:***_
******  ****Surfaces that **_**resist non-specific**_** **
**     **** **_**protein adsorption**_** are important to**
**     **** ****many applications ranging from**
**     **** ****biosensors to biomedical devices.**
******  ****There is a lack of the **_**molecular-level**_
**     **** **_**understanding**_** of **_**non-fouling**_
**     **_** **__**mechanism**_**, which prevents the**
**     **** ****rational design of non-fouling **
**     **** ****materials.**
_***Scientific Uniqueness:***_
******  ****Controlling nano-scale surface **
**     **** ****properties of OEG SAMs for protein**
**     **** ****adsorption.**
******  **_**Predicting and probing hydration**_
**     **** **_**around OEG chains**_**.**
******  ****Relating molecular-level properties **
**     **** ****to non-fouling behavior**

-                                                                                                                                                                           CTS-0308598-SGER

## PHASE EQUILIBRIUM & SOLUTION THERMODYNAMICS

**Simulations of Complex Fluids**
**Molecular Simulations**
- Experimental Studies
**Polymer systems**
**Environmental Implications**
**Surface Phenomena & Microscale**
**Biological (with other programs)**
**	****	****	****	****Examples Follow:**

***Emphasis Areas:***

## Proteins under pressure: Insights from MD simulations

**Pressure unfolding of staphnuclease **
**studied by MD simulations**

**Background:**
******  ****Thermodynamic **_**stability of folded proteins depends sensitively on T, P, and presence of salts and additives**_** in aqueous solution.  Despite the explosion in experimental data, effects of high hydrostatic pressure on protein**
**structure-function are poorly understood.**
****** ****Statistical mechanics and MD simulation methods are used to study pressure effects on biomolecules. **
****** ****The approach is unique; it combines novel MD simulation methods, macroscopic thermodynamics, and experimental protein structure & stability data.  **
****** ****New insights are obtained both at the level of fundamental interactions and protein structural changes.**

**Shekhar Garde**** - Rensselaer Polytechnic Institute**

-                                                                                                                                                                           CTS-0304055-CAREER

** ****Pressure**