# Presentation: 024269

## Interfacial Processing

**Transport and Thermal Fluids Cluster**
**Interfacial Processing**
**and Thermodynamics**
**Program Director  -  Bob Wellek  -  ****rwellek@nsf.gov**

**Research Focus and Trends**
****** ****Advanced Materials Processing**
****** ****Bio-processing**
****** ****Energy**
****** ****Environmental**
****** ****Water Processing Applications**

## Phenomenological Considerations

**** **Directed- and Self-Molecular Assembly**** **
**   **** ****of novel Surfactant-Based Films, Structures, **
**   **** ****and Composites, including polymers**
**** **Bio-molecular Interfaces**
**** **Nano-materials for Functional Materials****,**
**   **** ****such as used for sensors and **
**   **** ****anti-fouling surfaces**
**** **Polymer Micro- and Nanostructures**
**** **Molecular Thermodynamics**
**   **** ****and Mass Transfer**

## Budget FY 2008 - Approximately $6.1 Million

_**Description**_
**Total Proposals Received**
**Unsolicited Awards**
**CAREER (18 Proposals)**
**SGER**
**GOALI**
**Workshop/Conferences**
**Supplements **(**REU, etc.**)

_**#**__** of **__**Awards**_
**179**
**21**
**3**
**1**
**1**
**7**
**9**

_**Total Dollars**_
**	****	****      ****- - -**
**$5,540,000**
******* $1,231,000**
** **
******* $100,000**
**$76,000**
**$79,000**
******* NOTE: Supplements included in figure**

## Interfacial Phenomena

**Emphasis Areas:**
**** **Functional Micro- & Nano-structures and**
**    **** ****Materials**
****** ****Molecular Assembly in Solution**
****** ****Bio-related Functional Surfaces**
**** **Polymer & Other Materials Processing - -**
**    **** ****Thin Polymer Films and Coatings**

## Mass Transport

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

## Phase Equilibrium and

**Solution Thermodynamics**

**Emphasis Areas:**
**** **Simulations of Complex Fluids**
**** **Molecular Simulations**** **(Compared with Experimental Studies)
****  **Polymer systems**
****  **Environmental Implications**
****  **Surface Phenomena & Microscale**
**** **Biological **(with Other Programs)

## Materials for Significant Savings 

**in Costs for Purification**

**** **A new class of porous carbons has been**
**    **** ****synthesized recently using silica materials with**
**    **** ****regular pores as a template**
**** **Provides a clear picture of the arrangement of **
**    **** ****carbon atoms at the local level in microporous **
**    **** ****and mesoporous carbons, which are widely **
**    **** ****used in industrial purification applications.**
**  **
**** **Uses a simulation Hybrid Reverse Monte Carlo**
**    **** ****method (HRMC) to model microporous carbons**
**    **** ****(the microporosity as well as the texture of**
**    **** ****micropores).  **
**** **These models provide a better understanding of **
**    **** ****the adsorption and diffusion properties **
**    **** ****observed in these materials**

**GOALI: Molecular Modeling of Confined Nano-Phases **
**and Nano-Porous Materials**
**Keith Gubbins  -  North Carolina State University**

**CBET-0211792**

## Biosensors with 

**Novel Polymer Surfaces**

**** **Bio-sensors: Use of special **
**    **** ****polymers that are selectively**
**    **** ****responsive to bio-molecules.**
**    **** ****The function of biosensors to**
**    **** ****recognize specific proteins **
**    **** ****(analyte) is based on selective **
**    **** ****binding of the analyte coupled **
**    **** ****with a process that signals the **
**    **** ****presence of the bound protein.**
**  **
**** **Developed a general molecular theory that provides quantitative**
**    **** ****predictions for the properties of responsive polymer layers.  **
**** **Developed the first complete treatment of equilibrium current-voltage**
**    **** ****curves for electrochemically active polymer modified electrodes**** **

**Igal Szleifer  -  Purdue University**

**CBET-0338377**

## Targeted Drug and Therapeutic Delivery to Cell Membranes

**** **Model Simulations of **
**    ****vesicle-bud formation **
**    ****in cell membranes **
**    ****under the influence  **
**    ****of curvature inducing **
**    ****proteins**
**** **Novel Applications of **
**    **** ****multiscale modeling in systems biology, pharmacology by**
**    **** ****providing routes to discern pathological cellular trafficking**
**    **** ****fates**
** **
**** **Discovery of hidden biological mechanisms involved in**
**    **** ****intercellular signaling**

**Ravi Radhakrishna  -  University of Pennsylvania**

**CBET-0730955**

## Assembly of Nano-Scale Crystals for Medicine Delivery and New Micro-electronic Circuits

**** **Demonstrated the general strategy **
**    **** ****of using nanoscale confinement to **
**    **** ****direct the assembly of nano-components.**
****** ****Fabricated self-assembled “molecular” **
**    **** ****templates using a variety of amphiphiles.  **
**    **** ****The templates were used to **
**    **** ****achieve site-specific deposition **
**    **** ****and crystallization of **
**    **** ****semiconductor metal sulfides and the drug aspirin with molecular**
**    **** ****precision.**
** **
**** **Also fabricated particle/rod hybrid nanostructures using nanoparticles **
**    **** ****as the “seed” template.**
**** **New approach shows control can be achieved without stringent**
**    **** ****constraints and with no prior knowledge of the guest crystal structure. **

**Guangzhao Mao  -**
**Wayne State University**

**CBET-0553533**

## Phase Behavior of Block and Graft Styrene Copolymers in Near-critical and Super-critical Solvents

****** ****All known drug-delivery nanoparticles**
**      ****made in aqueous solutions have a low**
**      ****concentration of hydrophobic drugs **
**      ****(low drug loading) and require an **
**      ****expensive freeze-dry process to **
**      ****recover a dry product.**
****** ****For the first time, researchers have **
**    ****been able to gain insights into solvent **
**    ****compressibility effects on block-copolymer **
**    ****micellization and relate them to the homopolymer phase behavior. **
** **
**** **These insights open up new approaches to controlling micelle formation and drug**
**    ****partitioning with small changes in solution pressure, rather than with changes in**
**    ****solution temperature and composition alone.**
****** ****Near critical solvents should allow for a pressure-tuned drug partitioning, hence**
**    ****higher drug loading, and a more efficient dry-product recovery upon solvent**
**    ****decompression.  **

**Maciej Radosz  -  **
**University of Wyoming**

**CBET-0244388**

## Sensors: Biosensor Arrays from Intact Receptor Proteoliposomes  Immobilized onto Surfaces

****  **Membrane receptors represent the single **
**largest category of cell surface targets with **
**therapeutic effects, but they require the lipid **
**bilayer’s hydrophobic environment to maintain **
**activity *****ex vivo*****.  This requirement prevents **
**forming sensor arrays using fluid spotting. **
**Previous efforts have incorporated the membrane **
**receptors into planar bilayer structures on **
**surfaces in order to fulfill the requirement of a **
**lipid environment to maintain their activity. **
****  **It is shown that small liposomes remain intact when adsorbed inside functionalized microwells that attract the liposomes.  The size of the liposomes is matched to the size of the wells so that only one liposome attaches into each well.  The background surface is functionalized with a polyethylene glycol oligomer to resist liposome adsorption and unraveling. **
******  ****It is also shown the applicability of the liposome microarray platform for bio-detection.  GM1 receptors incorporated into the liposome arrays bind with high selectivity and specificity the Cholera Toxin Subunit B.**** **

**Alexander Couzis, Charles Maldarelli, **
**Lane Gilchrist, and David Calhoun – **
**City College of New York**

**CTS-0428673**

## Molecular Recognition in Microarrays: 

**A Computer Simulation Study**

****** ****Lattice Monte Carlo Simulations**
**Objective:****  ****Use lattice Monte Carlo simulation to develop **
**guidelines for designing microarrays with maximum **
**sensitivity and specificity**
**Method and Systems**
**Self avoiding walk on a 3D cubic lattice**
**Lattice Monte Carlo in NVT ensemble**
**Each segment represents a sequence of nucleotides **
**Each “Target” segment uniquely hybridizes with corresponding **
**   “****Probe” segment with hybridization energy ****ε*******
**Modeled one****1**** and multiple****2**** DNA probe molecules hybridizing **
**   ****with one target****1**** and multiple target****2**** molecules**
**** **Intermediate resolution DNA model**
**Objective:****  ****Develop an intermediate resolution model for **
**single and double stranded DNA suitable for use with **
**discontinuous molecular dynamics (DMD) to study **
**hybridization process on microarrays**

**Carol K Hall  -**
**North Carolina State University**

**CBET- 0625888**

**Cartoon juxtaposing atomic resolution of a double-stranded B-DNA decamer (AT)5 which contains 639 sites (excluding hydrogen) and the coarse-grained model representation which contains 58 sites.**

**1**  **Jayaraman** et. al. ***Biophys J*** (2006) **92** 2227
**2**  **Jayaraman** et. al. ***J Chem Phys**** *(2007) in press

## CAREER: Heterogeneous and Competitive 

**Self-assembly at Liquid-Liquid Interfaces**

******  ****Goals:****  To integrate research and education centering on heterogeneous and competitive self-assembly at liquid-liquid interfaces. **
****  **Approaches:****  **
**To self-assemble heterogeneous colloidal lattices at Pickering emulsion interfaces.  **
**To simulate heterogeneous or competitive self-assembly of surfactants and nanoparticles at liquid-liquid interfaces**
****  **Results (Part I):  Heterogeneous Colloidal Lattices:**** **
**Sulfate-treated polystyrene particles can form **
**heterogeneous colloidal lattices made of 0.2 mm and 1mm**
**Presence of carboxylate-treated polystyrene particles (in red) inhibits the formation of colloidal lattices but a small percentage can be incorporated into a binary colloidal lattice made of mostly sulfate-treated polystyrene particles (in green)**
****  **Results (Part II):  MD Simulations of Interfacial **
**Self-assembly of Surfactants and Nanoparticles**** **
**Simulate migration and final equilibrium of surfactant sodium dodecylsulfate (SDS) and modified hydrocarbon nanoparticles**
**“****Attachment” of surfactants to nanoparticles in water **
**followed by “detachment” at oil-water interfaces**
**At low surfactant concentration, surfactants & nanoparticles **
**co-equilibrate at the interfaces whereas at high surfactant **
**concentration, the surfactants deplete nanoparticles away.**

**Lenore L. Dai  -  Texas Tech University**

**CBET-0644850**

**In-situ self-assembly of nanoparticles (in red) **
**and surfactants (in yellow)**