Interfacial Processing

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NSF Directorate for Engineering Division
of Chemical, Bioengineering, Environmental, and
Transport Systems (CBET) Transport and Thermal
Fluids Cluster Interfacial Processing and
Thermodynamics Program Director - Bob Wellek
- rwellek_at_nsf.gov

• Research Impact Focus and Trends
• ? Advanced Materials Processing at the Interface
• ? Bio-molecular Processing at the Interface
• ? Interfacial and Transport Processes with
• Impact on Energy and Environmental Issues

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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
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Budget FY 2009 - Approximately 6.8 Million
Description Total Proposals Received Unsolicited
Awards CAREER (18 Proposals) EAGER GOALI Work
shop/Conferences Supplements (REU, etc.)
of Awards 223 24 4 1 1 12 9
Total Dollars - - - 3,956,000
406,000 50,000 375,000 201,000 94,000
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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, Particles and Coatings

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Mass Transport

• Emphasis Areas
• ? Bioprocessing Biomedical Materials
• at Interfaces
• ? Membranes, Polymer (with other programs)
• ? Diffusion Transport in Supercritical Fluids
• and along/at Interface
• ? Molecular Modeling Simulation

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Phase Equilibrium and Solution Thermodynamics

• Emphasis Areas
• ? Simulations of Complex Fluids
• ? Energy and Environmental Implications
• ? Surface Phenomena Microscale
• ? Biological (with Other Programs)
• ? Polymer Systems
• ? Molecular Simulations (Compared with
  Experimental Studies)

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Molecular Recognition in Microarrays A Computer
Simulation Study
Carol K Hall - North Carolina State University

• ? 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
• ? Intermediate resolution DNA model

Cartoon juxtaposing atomic resolution of a
double-stranded B-DNA decamer
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CBET- 0625888
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Biosensors with Novel Polymer Surfaces
Igal Szleifer - Purdue University

• ? 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

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CBET-0338377
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Targeted Drug and Therapeutic Delivery to Cell
Membranes
Ravi Radhakrishna - University of Pennsylvania
? 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
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CBET-0730955
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Sensors Biosensor Arrays from Intact Receptor
Proteoliposomes Immobilized onto Surfaces
Alexander Couzis, Charles Maldarelli, Lane
Gilchrist, and David Calhoun City College of
New York

• ? Membrane receptors represent the single
• largest category of cell surface targets with
• therapeutic effects, but they require the lipid
• bilayers 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.

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CTS-0428673
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CAREER Heterogeneous and Competitive
Self-assembly at Liquid-Liquid Interfaces
Lenore L. Dai - Texas Tech University
? 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.
In-situ self-assembly of nanoparticles (in red)
and surfactants (in yellow)
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CBET-0644850
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Phase Behavior of Block and Graft Styrene
Copolymers in Near-critical and Super-critical
Solvents
Maciej Radosz - University of Wyoming

• ? 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.

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CBET-0244388