A5009302567- Silicone and Siloxane Chemistry
- Advanced Cellulose Research Studies
- Polymer Surface Interaction Studies
- Marine Biology and Environmental Chemistry
- Surface Modification and Superhydrophobicity
- Nanocomposite Films for Food Packaging
- Surfactants and Colloidal Systems
- Lignin and Wood Chemistry
- Polymer Nanocomposites and Properties
- Polymer crystallization and properties
- Block Copolymer Self-Assembly
- Advanced Polymer Synthesis and Characterization
- Fluid Dynamics and Thin Films
- Polysaccharides and Plant Cell Walls
- Force Microscopy Techniques and Applications
- Lipid Membrane Structure and Behavior
- Electrostatics and Colloid Interactions
- Polysaccharides Composition and Applications
- Biofuel production and bioconversion
- biodegradable polymer synthesis and properties
- Conducting polymers and applications
- Dendrimers and Hyperbranched Polymers
- Polymer composites and self-healing
- Synthesis and properties of polymers
- Advanced Sensor and Energy Harvesting Materials
Virginia Tech
2015-2024
Interface (United States)
2014-2016
Friedrich Schiller University Jena
2009
Virginia Commonwealth University
2009
KTH Royal Institute of Technology
2007
Institute for Atomic and Molecular Physics
2007
Dutch Polymer Institute
2007
Eindhoven University of Technology
2007
National Institute of Standards and Technology
2000-2007
Czech Academy of Sciences, Institute of Macromolecular Chemistry
2007
The jasmonate family of phytohormones plays central roles in plant development and stress acclimation. However, the architecture their signaling circuits remains largely unknown. Here we describe a binding protein, cyclophilin 20-3 (CYP20-3), which regulates stress-responsive cellular redox homeostasis. (+)-12-oxo-phytodienoic acid (OPDA) promotes CYP20-3 to form complex with serine acetyltransferase 1, triggers formation hetero-oligomeric cysteine synthase O -acetylserine(thiol)lyase B...
Cellulose nanocrystals (CNCs) prepared by H2SO4 hydrolysis have sulfate groups on their surface, which negative implications for some CNC applications. In this study, two desulfation methods were evaluated, and the properties of desulfated CNCs compared to those unsulfated CNCs, HCl hydrolysis. H2SO4-hydrolyzed from softwood sulfite pulp subjected either a mild acid hydrolytic or solvolytic in dimethyl sulfoxide via pyridinium salt. Removal was confirmed conductometric titration X-ray...
A new magnetic resonance imaging (MRI) contrast agent based on the trimetallic nitride templated (TNT) metallofullerene Gd(3)N@C(80) was synthesized by a facile method in high yield. The observed longitudinal and transverse relaxivities r(1) r(2) for water hydrogens presence of water-soluble gadofullerene 2 Gd(3)N@C(80)(OH)(approximately 26)(CH(2)CH(2)COOM)(approximately 16) (M = Na or H) are 207 282 mM(-1) s(-1) (per C(80) cage) at 2.4 T, respectively; these values 50 times larger than...
Adsorption of anionic polyelectrolytes, sodium salts carboxymethyl celluloses (CMCs) with different degrees substitution (DS = 0.9 and 1.2), from aqueous electrolyte solutions onto regenerated cellulose surfaces was studied using quartz crystal microbalance dissipation monitoring (QCM-D) surface plasmon resonance (SPR) experiments. The influence both calcium chloride (CaCl(2)) (NaCl) on CMC adsorption examined. QCM-D results demonstrated that CaCl(2) (divalent cation) caused significantly...
Model cellulose surfaces have attracted increasing attention for studying interactions with cell wall matrix polymers and as substrates enzymatic degradation studies. Quartz crystal microbalance dissipation monitoring (QCM-D) solvent exchange studies showed that the water content of regenerated (RC) films was proportional to film thickness (d) consistent about five molecules per anhydroglucose unit. Sulfated nanocrystalline (SNC) desulfated (DNC) had comparable contents contained times more...
Understanding the binder–powder interaction and primitive formation is critical to advancing binder jetting Additive Manufacturing process improving accuracy, precision, mechanical properties of printed parts. In this work, authors propose an experimental approach based on sessile drop goniometry a powder substrate characterize wetting process. As penetrates into prepared substrate, dynamic contact angle formed in pores calculated measured penetration time, depth from binder-powder granule...
(1,3)(1,4)-β-D-Glucan (mixed-linkage glucan or MLG), a characteristic hemicellulose in primary cell walls of grasses, was investigated to determine both its role and interaction with cellulose other wall polysaccharides vitro. Binding isotherms showed that MLG adsorption onto microcrystalline is slow, irreversible, temperature-dependent. Measurements using quartz crystal microbalance dissipation monitoring adsorbed irreversibly amorphous regenerated cellulose, forming thick hydrogel....
Abstract Lead halide perovskite solar cells (PSCs) have demonstrated great potential for realizing low‐cost and easily fabricated photovoltaics. At this juncture, power conversion efficiency long‐term stability are two important factors limiting their transition. PSCs exhibit rapid environmental degradation since the layer is very sensitive to such as humidity, temperature, ultraviolet light. Here, a novel successful approach that simultaneously improves of PSCs. This relies on incorporation...
Chitin is the second most abundant biopolymer and insight into its natural synthesis, enzymatic degradation, chemical interactions with other biopolymers important for bioengineering this renewable resource. This work first report of smooth, homogeneous, ultrathin chitin films, opening door to surface studies binding interactions, adsorption kinetics, degradation. The films were formed by spincoating trimethylsilyl onto gold or silica substrates, followed regeneration a film. Infrared X-ray...
Porous carbon scaffolds can host lithium (Li) metal anodes to potentially enable stable Li batteries. However, the poor wettability on surface has inhibited uniform distribution of metallic most scaffolds. Herein, this work reports a lithiophilic top layer through mild ozonolysis and ammoniation methods universally facilitate infiltration liquid into matrices. Based finding, thin, lightweight Li@carbon film (CF) composite anode with high practical capacity 3222 mAh g−1 suppressed volume...
Posttransfer modification of preformed Langmuir-Blodgett films poly(tert-butyl methacrylate) and acrylate) by gaseous hydrochloric acid yields with layered architecture poly(methacrylic acid) poly(acrylic acid), respectively. X-ray reflectivity infrared spectroscopy confirm monolayer transfer the source polymers their transformation to multilayer assemblies retention low surface roughnesses. The incorporation cross-linking groups into system offers possibility for further chemical produce...
Insoluble films of trisilanolisobutyl-POSS and octaisobutyl-POSS at the air/water interface are investigated by means surface pressure - area per molecule isotherm (Pi A) Brewster angle microscopy (BAM). Analysis experimental results shows partial cage molecule, trisilanolisobutyl-POSS, is a surface-active that self-assembles into uniform monolayer upon compression; but fully condensed octaisobutyl-POSS, nonamphiphilic.
Combining two non-surface-active building blocks, oligomeric poly(ethylene glycol) (PEG) and a completely hydrophobic polyhedral silsesquioxane (POSS) cage, creates amphiphilic telechelic polymers (POSS−PEG−POSS), which exhibit surface activity at the air/water (A/W) interface. POSS moieties serve as groups for hydrophilic PEG chains of different number-average molar mass (1, 2, 3.4, 8, 10 kg mol-1). For short 3.4 mol-1), insoluble monolayers form, whereas end were not sufficiently to keep...
Surface pressure-induced crystallization of poly(ε-caprolactone) (PCL) from a metastable region the surface pressure−area per monomer (Π−A) isotherm in Langmuir monolayers at air/water (A/W) interface has been captured real time by Brewster angle microscopy (BAM). Morphological features PCL crystals grown films during compression process exhibit four fully developed faces and two distorted faces. During expansion crystallized film, polymer chains slowly detach crystalline domains diffuse...
Improving the efficiency of enzymatic hydrolysis cellulose is one key technological hurdles to reduce cost producing ethanol and other transportation fuels from lignocellulosic material. A better understanding how soluble enzymes interact with insoluble will aid in design more efficient enzyme systems. We report a study involving neutron reflectometry (NR) quartz crystal microbalance dissipation monitoring (QCM-D) interaction fungal extract (T. viride) an endoglucanse A. niger amorphous...
Pretreatment of lignocellulosic biomass with sulfuric acid may leave sulfate groups on its surface that hinder biochemical conversion. This study investigates the effects cellulase adsorption onto cellulose substrates and enzymatic hydrolysis these substrates. Substrates different group densities were prepared from H2SO4- HCl-hydrolyzed partially fully desulfated nanocrystals. Adsorption was analyzed by quartz crystal microbalance dissipation monitoring (QCM-D). The roughness substrates,...
Surface plasmon resonance studies showed pullulan cinnamates (PCs) with varying degrees of substitution (DS) adsorbed onto regenerated cellulose surfaces from aqueous solutions below their critical aggregation concentrations. Results on were compared to PC adsorption hydrophilic and hydrophobic self-assembled thiol monolayers (SAMs) gold probe how different interactions affected adsorption. methyl-terminated SAMs (SAM-CH3) > hydroxyl-terminated (SAM-OH) for high DS increased each surface....
Hair-derived keratin biomaterials composed mostly of reduced proteins (kerateines) have demonstrated their utility as carriers biologics and drugs for tissue engineering. Electrostatic forces between negatively-charged keratins biologic macromolecules allow effective drug retention; attraction to positively-charged growth factors like bone morphogenetic protein 2 (BMP-2) has been used a strategy osteoinduction. In this study, the intermolecular surface bulk interaction properties kerateines...