A5037714245- Spectroscopy and Quantum Chemical Studies
- Surfactants and Colloidal Systems
- Lipid Membrane Structure and Behavior
- Mechanical and Optical Resonators
- Advanced Chemical Sensor Technologies
- Electrospun Nanofibers in Biomedical Applications
- Advanced Cellulose Research Studies
- Electrostatics and Colloid Interactions
- Analytical Chemistry and Sensors
- Spectroscopy and Laser Applications
- Fibroblast Growth Factor Research
- Acoustic Wave Resonator Technologies
- Quantum Dots Synthesis And Properties
- Gold and Silver Nanoparticles Synthesis and Applications
- Nerve injury and regeneration
- Molecular Junctions and Nanostructures
- Force Microscopy Techniques and Applications
- Laser-Ablation Synthesis of Nanoparticles
- Photochemistry and Electron Transfer Studies
- Natural Fiber Reinforced Composites
- Endoplasmic Reticulum Stress and Disease
- Surface Modification and Superhydrophobicity
- Interdisciplinary Research and Collaboration
- Advanced Fluorescence Microscopy Techniques
- Neonatal Respiratory Health Research
University of Maine
2012-2024
University of Cambridge
2000-2004
Maine Medical Center Research Institute
2004
Jackson Laboratory
2004
Heidelberg University
2004
Hokkaido University
2004
University of Toronto
2000
Xerox (Canada)
1997-1998
The University of Melbourne
1997-1998
Nanometer scale carbon fibers (carbon nanofibers) are of great interest to scientists and engineers in fields such as materials science, composite production, energy storage due their unique chemical, physical, mechanical properties. Precursors currently used for production nanofibers primarily from nonrenewable resources. Lignin is a renewable natural polymer existing all high-level plants that byproduct the papermaking process potential feedstock nanofiber production. The work presented...
Sum frequency generation (SFG) vibrational spectra of cadmium arachidate multilayer films adsorbed on a substrate with high nonresonant susceptibility, i.e., gold, and low susceptibility substrate, fused quartz, have been investigated in the C−H stretching region air. The were formed by Langmuir−Blodgett (LB) deposition their recorded using SFG spectrometers employing both 532-nm nanosecond 800-nm femtosecond lasers, counter-propagating co-propagating beam geometries, respectively. Both...
Sum frequency (SF) vibrational spectra in the C−H stretching region of polydimethyl siloxane (PDMS) and comb copolymer cetyl dimethicone copolyol (CDC), consisting a PDMS backbone with grafted poly(ethylene oxide) side chains, have been recorded air after deposition onto gold-coated substrate. The polymers were deposited over range thicknesses (up to 70 nm) by spin coating from chloroform solutions different polymer concentrations. Film determined ellipsometry. methyl symmetric (r+) modes...
Cellulose nanomaterials are produced employing a multitude of methodologies including electrospinning, bacterial generation, acid digestion, and variety mechanical defibrillation techniques; the morphology nanomaterial is specific to production process. Feedstocks range from various forms woody biomass, fungi, have great impact on resulting product. The technique, such as that employed in present work, continuously breaks down cellulose fibers suspended water via segmentation through...
Polarized infrared attenuated reflection (IR-ATR) has been used to determine the average orientation of methylene tail cetyltrimethylammonium bromide (CTAB) adsorbed at silica/solution interface under both equilibrium and nonequilibrium conditions, in situ. The was measured over pH range 2−10. It found that surfactant larger higher values owing an increase packing density with increasing surface excess. evolution during adsorption process monitored a 9.2. To authors' knowledge, this is first...
Adsorption of poly(styrenesulfonate) (PSS) and cetyltrimethylammonium bromide (CTAB) on silica from mixed solutions the polyelectrolyte surfactant has been studied. The surface excess was determined by ultraviolet attenuated total reflectance (UV-ATR) monitoring 224 nm styrenesulfonate absorbance band. Complementary information derived infrared (IR-ATR) same system. Deconvolution 2920 cm-1 asymmetric 2850 symmetric methylene bands common to both gave adsorbed amount surfactant, as well a...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSum Frequency Generation on Surfactant-Coated Gold NanoparticlesTakeshi Kawai, David J. Neivandt, and Paul B. DaviesView Author Information Department of Chemistry, University Cambridge Lensfield Road, CB2 1EW, UK Cite this: Am. Chem. Soc. 2000, 122, 48, 12031–12032Publication Date (Web):November 14, 2000Publication History Received28 July 2000Published online14 November inissue 1 December...
Abstract In an effort to improve the adhesive bonding between wood–plastic composites (WPCs) formulated with polypropylene and a commercial epoxy adhesive, surface treatments were performed chemically and/or physically modify of WPCs. The on extruded WPC that had been planed consisted chromic acid treatment, flame water then treatment treatment. strength bonds treated samples was tested following ASTM D 905 maximum shear stress calculated for each increased their respective average strengths...
Extracellular proteins devoid of signal peptides use nonclassical secretion mechanisms for their export. These are independent the endoplasmic reticulum and Golgi. Some nonclassically released proteins, particularly fibroblast growth factors (FGF) 1 2, exported as a result direct translocation through cell membrane. This process requires specific interactions with membrane phospholipids. In this review written by biologist, structural biologist two engineers, we discuss following subjects:...
A theoretical model has been developed to describe the generation of Sum Frequency (SF) light from a monolayer film adsorbed surface dielectric and metal composite substrate. This type substrate provides enhanced SF signals without modifying intrinsic (hydrophilic) properties surface. The fundamental equations both resonant nonresonant have extended single interface encompass two displaced sources, air/dielectric at which is located, dielectric/metal interface. describes coherent addition...
To have a better knowledge of the phenomena that affect adhesion characteristics wood plastic composites (WPCs) series surface treatments was performed. The consisted chemical, mechanical, energetic, physical, and combination energetic physical WPC modifications. After each treatment, composite boards were bonded using commercial epoxy adhesive, bond shear strength determined according to ASTM D 905. All treatments, except mechanical one, performed presented in previous paper (W. Gramlich et...
Forced atmospheric (air) plasma treatment (FAPT) was applied to wood plastic composite (WPC) and continuous glass fiber reinforced (FRP) surfaces improve their adhesive bonding properties. The FRP composed of oriented E-glass fibers in a polypropylene matrix, while the WPC fabricated using flour, additives. FAPT two levels discharge length projected from head (2.5″ 1″) ionize air, oxidize wettability. performed by passing electrode over either surface, five or ten times. Surface...
The ordering of sodium dodecyl sulfate, SDS, at the hydrophobic solid/aqueous solution interface has been studied as a function addition cationic polyelectrolyte poly(ethylenimine), PEI, and univalent electrolyte chloride (NaCl) to solution. nonlinear optical technique sum frequency vibrational spectroscopy (SFS) was employed determine alkyl chain adsorbed surfactant. Sodium found promote onset ordered SDS adsorption lower bulk concentrations, result interpreted primarily in terms...
In the United States, approximately 20% of all foodborne disease outbreaks result from consumption seafood products. Specifically, Paralytic Shellfish Poisoning (PSP) is caused by consuming molluscan shellfish contaminated with a suite neurotoxins most potent which saxitoxin (STX). The current method for detecting STX mouse bioassay in exposed to sample and time required perish noted. length die used estimate level original sample. Since this technique costly laboratory-based procedure,...
A reaction protocol has been developed which when rigorously adhered to leads the reproducible formation of complete, well-ordered monolayers octadecylsiloxane (ODS) on mica. The complementary information provided by atomic force microscopy (AFM), sum frequency spectroscopy (SFS), and contact angle measurements used validate characterize structure coverage films. essential prerequisites for reproducibility were found be fresh octadecyltrichlorosilane (OTS), a clean environment, controlled...
The polar orientation and degree of conformational order sodium dodecyl sulfate (SDS) adsorbed at the hydrophobic octadecane thiol/aqueous solution interface has been investigated as a function surfactant concentration in presence absence fixed poly(ethylene oxide) (PEO). Sum frequency vibrational spectroscopy, based on nonlinear optical phenomenon sum generation, was employed to obtain spectra interfacial surfactant; weak signals from PEO were also obtained. phase indicated that both...