A5008014184- Polymer Surface Interaction Studies
- Microfluidic and Capillary Electrophoresis Applications
- Graphene research and applications
- Analytical Chemistry and Chromatography
- Silicone and Siloxane Chemistry
- Mesoporous Materials and Catalysis
- Analytical Chemistry and Sensors
- Electrochemical Analysis and Applications
- Advanced Sensor and Energy Harvesting Materials
- Synthesis and properties of polymers
- Molecular Junctions and Nanostructures
- Advanced biosensing and bioanalysis techniques
- Carbon Nanotubes in Composites
- Advanced Cellulose Research Studies
- Natural Fiber Reinforced Composites
- Electrochemical sensors and biosensors
- Force Microscopy Techniques and Applications
- High-pressure geophysics and materials
- Near-Field Optical Microscopy
- Crystallization and Solubility Studies
- Antimicrobial agents and applications
- Protein purification and stability
- Surface Modification and Superhydrophobicity
- Graphene and Nanomaterials Applications
- Microplastics and Plastic Pollution
Virginia Commonwealth University
2015-2020
Yokohama National University
2012-2014
Bangladesh Atomic Energy Commission
2012
University of Dhaka
2008
Infection is a serious medical complication associated with health care environments. Despite advances, the 5–10% incidence of infections for hospital patients well documented. Sources pathogenic organisms include devices such as catheters and endotracheal tubes. Offering guidance curbing spread infections, model antimicrobial coating described herein that kills bacteria on contact but compatible human cells. To achieve these characteristics, novel blend conventional biomedical grade...
Surface wettability gradients were used to elongate and align double stranded λ-DNA. Gradients prepared by vapor phase deposition of octyltrichlorosilane (C8-silane) fluorinated (F-silane) precursors. Gradient formation was confirmed water contact angle ellipsometric film thickness measurements. Placement a droplet aqueous DNA solution on the hydrophobic end each gradient led spontaneous motion toward hydrophilic DNA. Fluorescence imaging surface-adsorbed YOYO-1 labeled molecules revealed...
The mass transport of hydrophobic probe molecules on gradient self-assembled monolayers (SAMs) is investigated in the presence nanometer-thick layers water condensed from ambient atmosphere at low, moderate, and high relative humidity (RH). SAM gradients are prepared by vapor-phase deposition 3-cyanopropyltrichlorosilane (CN) octyltrichlorosilane (C8) onto silica silicon substrates. two-component thus obtained run opposite directions, with CN coverage where C8 low. Gradient formation...
Stationary phase gradients on monolithic silica columns have been successfully and reproducibly prepared characterized with comparisons made to uniformly modified stationary phases. hold great potential for use in liquid chromatography (LC), both terms of simplifying analysis as well providing novel selectivity. In this work, we demonstrate the creation a continuous gradient in-house synthesized by infusing an aminoalkoxysilane solution through monoliths via controlled rate infusion. The...
Bifunctionalized surface charge gradients in which the individual component either align with or oppose each other have been prepared. The multicomponent contain strongly acidic, weakly and basic functionalities that cooperatively interact to define wettability, nanoparticle binding, charge. two-step process for gradient formation begins by modifying a siloxane coated silicon wafer spatially dependent fashion first an aminoalkoxysilane then mercapto-functionalized alkoxysilane. Immersion...
The mechanical properties of the coir fibers were evaluated in this study. Tensile strength (TS), Young’s modulus (YM) and elongation at break (Eb%) virgin found to be 152 MPa, 5.3 GPa 36%, respectively. Coir treated with ultraviolet (UV) radiation improve significantly. fiber-reinforced ethylene glycol dimethacrylate (EGDMA)-based composite was prepared characterized. surface modified monomer EGDMA under UV radiation. Soaking time, (EGDMA) concentration intensities optimized over...
Protonated amine gradients have been prepared on silicon wafers via programmed controlled rate infusion (CRI) with varying degrees of hydrophobicity and characterized by X-ray photoelectron spectroscopy (XPS) static Wilhelmy plate dynamic contact angle measurements. Initially, base layers were spin coated from sols containing tetramethoxysilane (TMOS) either phenyltrimethoxysilane (PTMOS), dimethyldimethoxysilane (DMDMOS), or octyltrimethoxysilane (OTMOS, C8). Amine then...
Single molecule detection methods were employed to study the potential dependent adsorption and desorption of dye labeled plasmid DNA along chemical gradients prepared on indium tin oxide (ITO) electrodes. Gradients formed over silica-base-layer-coated ITO surfaces by exposing them in a directional fashion aminopropyltrimethoxysilane from vapor phase. Sessile drop water contact angle measurements, spectroscopic ellipsometry, X-ray photoelectron spectroscopy used verify that gradient was...
Multifunctionalized pH-sensitive silica gradients containing acidic and basic functional groups have been prepared to evaluate how the spatial arrangement of active sites on a surface influences charge pH switchability. The gradient surfaces were using controlled rate infusion in such manner that individual strong acid (sulfonic acid) weak base (propylamine) align, whereas weakly silanol opposes them. relative amounts three species varied by controlling composition deposition solution,...
Platinum cure for poly(dimethylsiloxane) (PDMS) coatings on a thermal gradient (45–140 °C) was carried out to study the effect of temperature surface chemistry and wetting behavior. The motivation is interest in surfaces with continuous gradients wettability applications such as protein adsorption, controlling bacterial adhesion, directional movement cells, biosensors. Wilhelmy plate method advancing/receding drop were employed determining positional dependence θA θR. A strong receding...
Abstract The completion of the polycondensation sol‐gel derived organic‐inorganic hybrid silica by heat treatment was studied for powder samples prepared from vinyltrimethoxysilane and vinyltriethoxysilane. appropriate temperature submicron powdery both starting compounds determined through thermogravimetric analysis. or incompletion elucidated means several instrumental methods in addition to a light scattering test. lowest conditions particles vinyltriethoxysilane are 170 °C 180 °C,...
Empty fruit bunches of oil palm fibers can be used as environmentally friendly alternatives to conventional reinforcing fibers, like glass, carbon, etc. In order improve the interfacial properties, this fiber was subjected grafting with bulk monomer allyl methacrylate (AMA) and cured under UV radiation. It found that curing enhanced physicomechanical properties a large extent compared untreated virgin fiber. Among different AMA concentration, treated 10% showed best mechanical after 15...
Four multicomponent charge gradients containing acidic and basic functionalities were prepared via sol–gel processes the controlled-rate infusion (CRI) method to more clearly understand how preparation conditions influence macroscopic properties. CRI is used form by infusing reactive alkoxysilanes into a glass vial housing vertically oriented modified silicon wafer. The concentration time of silane solutions kept constant. Only sequence was changed. first set samples initially solution...