A5069640022- Advanced Cellulose Research Studies
- Nanocomposite Films for Food Packaging
- biodegradable polymer synthesis and properties
- Phase Equilibria and Thermodynamics
- Pickering emulsions and particle stabilization
- Block Copolymer Self-Assembly
- Electrospun Nanofibers in Biomedical Applications
- Material Dynamics and Properties
- Polymer Nanocomposites and Properties
- Polymer Surface Interaction Studies
- Surfactants and Colloidal Systems
- Surface Modification and Superhydrophobicity
- Adhesion, Friction, and Surface Interactions
- Enhanced Oil Recovery Techniques
- Machine Learning in Materials Science
- Polymer crystallization and properties
- 3D Printing in Biomedical Research
- Advanced Sensor and Energy Harvesting Materials
- Fluid Dynamics and Thin Films
- Plant Reproductive Biology
- Lignin and Wood Chemistry
- Bone Tissue Engineering Materials
- Polymer composites and self-healing
- Force Microscopy Techniques and Applications
- Nanofabrication and Lithography Techniques
Georgia Institute of Technology
2015-2024
AID Atlanta
2014-2020
Google (United States)
2018
Georgia Tech Research Institute
2009
Hewlett-Packard (United States)
2005
National Institute of Standards and Technology
1999-2003
National Institute of Standards
1999-2003
State University of New York
2001
Chevron Phillips Chemical (United States)
2001
The University of Texas at Austin
1996-2000
Abstract Hunger and chronic undernourishment impact over 800 million people, which translates to ≈10.7% of the world's population. While countries are increasingly making efforts reduce poverty hunger by pursuing sustainable energy agricultural practices, a third food produced around globe still is wasted never consumed. Reducing shortages vital in this effort often addressed development genetically modified produce or chemical additives inedible coatings, create additional health...
Protein adsorption onto synthetic materials influences cell adhesion and signaling events that direct function in numerous biomedical applications. Adsorption of fibronectin (FN) to different surfaces alters protein structure modulates α5β1 integrin binding, adhesion, spreading, migration. In the present study, self-assembled monolayers alkanethiols on Au were used analyze effects surface chemistry (CH3, OH, NH2, COOH) a recombinant fragment FN, FNIII7-10, incorporates both synergy RGD...
Combinatorial methods involving data collection in multiparameter space allow a rapid identification of measured property trends as function system parameters. The technique has been applied with success to pharmaceutical, inorganic and organic materials synthesis, but not significantly measurements polymeric films coatings. We demonstrate the use 2-D combinatorial libraries investigate thin-film dewetting. have prepared thin polystyrene on silicon substrates containing orthogonal,...
Chitin is an abundant biopolymer whose natural production second only to cellulose. Similar cellulose nanocrystals (CNCs) or nanofibers (CNFs), chitin (ChNFs) can be isolated and used as sustainable O2 barrier materials for food, electronics, pharmaceutical packaging. These bioavailable nanomaterials are readily dispersed in water enabling spray-coated films deposited at high rates onto uneven delicate surfaces. In the present study, we demonstrate successful layer-by-layer spray coating of...
The unequal reactivity of the two isocyanate groups in an isophorone diisocyante (IPDI) monomer was exploited to yield modified cellulose nanocrystals (CNCs) with both urethane and functionality. chemical functionality CNCs verified ATR-FTIR analysis elemental analysis. selectivity for secondary group using dibutyl tin dilaurate (DBTDL) as reaction catalyst confirmed (13)C NMR. showed improvements onset thermal degradation by 35 °C compared unmodified CNCs. Polyurethane composites based on...
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication the EditorNEXTHigh-Throughput Measurement of Polymer Blend Phase BehaviorJ. Carson Meredith, Alamgir Karim, and Eric J. AmisView Author Information Polymers Division, National Institute Standards Technology, Gaithersburg, Maryland 20899 Cite this: Macromolecules 2000, 33, 16, 5760–5762Publication Date (Web):July 15, 2000Publication History Received14 March 2000Revised31 May 2000Published online15 July inissue 1 August...
Abstract We report a novel combinatorial methodology for characterizing the effects of polymer surface features on cell function. Libraries containing hundreds to thousands distinct chemistries, microstructures, and roughnesses are prepared using composition spread temperature gradient techniques. The method enables orders magnitude increases in discovery rate, decreases variance, allows first time high‐throughput assays response physical chemical features. technique overcomes complex...
Equilibrium constants measured from the ν2 bending mode of CO2 by FTIR spectroscopy are reported for electron donor−acceptor interactions with three Lewis bases: triethylamine (TEA), pyridine (PYR), and tributyl phosphate (TBP). The average Kc values 0.046 (CO2−TEA), 0.133 (CO2−PYR), 1.29 (CO2−TBP) L/mol at 25 °C in solvent pentane. For CO2−TBP system, enthalpy association, ΔH°, is −4.7 kcal/mol. Ab initio calculations indicate that steric repulsion ethyl groups TEA cause binding energy...
We report on the facile preparation of highly scattering metal-coated polystyrene (PS) latex beads by using solvent-controlled heterocoagulation. Starting with an aqueous dispersion PS and poly(vinyl pyrrolidone)-capped metal nanoparticles (NPs), homogeneous dense coatings were obtained controlled addition removal tetrahydrofuran (THF). Different sizes (30, 60, 80 nm), chemistries (gold silver), shapes (sphere cube) NPs successfully incorporated commercially available beads. The resulting...
Plant pollens are microscopic particles exhibiting a remarkable breadth of complex solid surface features. In addition, many pollen grains coated with viscous liquid, “pollenkitt”, thought to play important roles in dispersion and adhesion. However, there exist no quantitative studies the effects features or pollenkitt on adhesion grains, it remains unclear what role these transport. We report AFM measurements five species series test surfaces which each has unique morphology volume. The...
The intricate hierarchical architectures in natural creatures are usually derived from assembly of molecular building blocks into nanoscale structures that then organize micro- and macroscopic sizes. An example is the complex structure arthropods (crustaceans, insects) constructed primarily chitin. Because chitin's inherent insolubility common solvents, processes for mimicking fascinating chitin-based nanostructures still at an early stage development. Here, we present a facile freeze-drying...
Chitin is the second most abundant biopolymer in nature and has tremendous potential renewable materials for packaging, energy storage, reinforced composites, biomedical engineering. Despite attractive properties, including biodegradability, antibacterial activity, high strength, chitin not utilized widely due to strong molecular interactions, which make solubilization processing difficult. We report a pressure homogenization route produce pure nanofibers (ChNFs) starting with mildly acidic...
Surface pattern formation in diblock copolymer films is investigated as a function of film thickness h and molecular mass M. Smooth are observed for certain ranges centered about multiples the lamellar L0, we attribute this effect to an increase surface chain density with outer brushlike layer. We also observe apparently stable labyrinthine patterns other ranges, average size these found scale lambda approximately L0(-2.5). Hole island occur between those smooth regions, their similarly decreases L0
A lower critical solution temperature (LCST) phase transition is reported for blends of the biodegradable polymers poly(D,L-lactide) (PDLA) and poly(ε-caprolactone) (PCL). From light scattering measurements cloud point curve determined to have a 86°C concentration mass fraction 36 wt.-% PCL. Optical microscopy phase-separated films indicates spinodal morphology at concentration, droplet phases off-critical concentrations. After quenching separated below melting PCL (60°C), crystallization...
Surfactants can adsorb in fluid–fluid interfaces and lower the interfacial tension. Like surfactants, particles with appropriate wettability also interfaces. Despite many studies of particle adsorption at fluid interfaces, some confusion persists regarding ability (simple, nonamphiphilic) to reduce In present work, activity silica nanoparticles air–water hexadecane–water ethyl cellulose interface water trimethylolpropane trimethacrylate was analyzed through pendant drop tensiometry. Our...
We investigate the solvent density driven changes in polymer conformation and phase behavior that occur a supercritical fluid, with particular emphasis on conditions near lower critical solution temperature (LCST) boundary. Using continuous space Monte Carlo simulations, mean square end-to-end distance (R) radius of gyration (Rg) are calculated for single chain 20 Lennard-Jones segments monomeric over broad range densities temperatures. The chains collapse as increases at constant pressure,...