Showing papers by "Pijush Ghosh published in 2022"
TL;DR: In this paper , a bilayer of chitosan and carboxymethyl cellulose (CMC) crosslinked with citric acid (CA) with tunable non-morphing points across the pH spectrum was presented.
Abstract: Hydrogel-based pH-responsive bilayer actuators exhibit bidirectional actuation due to the differences in the concentration gradient developed across the thickness, the volume expansion due to swelling, and the mechanical stiffness of the layers involved. At a pH value (point), where the sum of these factors generates moments of equal magnitudes, the moments cancel each other and result in no net actuation. This pH point is termed here as a "nonmorphing point". In this work, we present a bilayer of chitosan (CS) and carboxymethyl cellulose (CMC) cross-linked with citric acid (CA) with tunable nonmorphing points across the pH spectrum by modulating the concentration and cross-linking density of the layers involved. The standard CS/CMC bilayer films took about 40 s to completely fold (clockwise) in 0.1 M HCl and 78 s to completely fold (anticlockwise) in 0.1 M NaOH. Generally, pH-responsive actuators are designed for targeted drug delivery to a specific site inside the body as they show bidirectional (clockwise/anticlockwise) actuation around a single nonmorphing point. The same pH-responsive system cannot be applied for drug release at another site with a different functioning pH. Thus, having a pH-responsive system with multiple nonmorphing points is highly desirable. Drug release experiments were performed with FITC and EtBr as model drugs loaded in CS and CMC layers. Moreover, the clockwise/anticlockwise actuation of the bilayer around the nonmorphing point can facilitate or inhibit the release of a drug. The clockwise actuation resulted in 55% FITC release and inhibited EtBr release to 4%; anticlockwise actuation resulted in 50% EtBr release and inhibited FITC release to 5%. We demonstrated morphing induced drug release by hydrogel bilayer films with tunable nonmorphing points across the pH spectrum.
1 citations
TL;DR: In this article , the mechanism behind the interfacial adhesive strength between epoxy coating and soil was investigated, and the results indicated that the major contributions to the soil-polymer coating interface performance arise from the plastic deformation of epoxy which penetrates through clay surface pores.
1 citations
TL;DR: In this article , the anomalous stiffness evolution of a hydrogel with an increase in temperature was investigated through a finite element model, which considers the interplay between the water-filled fluid cavity, the surrounding viscoelastic chitosan matrix, and the temperature.
1 citations
TL;DR: In this article , an interplay between the desorption of intrinsic water and relaxation of polymer chains was reported, resulting in an unusual thermomechanical response of a hydrogel, wherein the elastic modulus increases in a certain temperature range followed by a sharp decrease with a further increase in temperature.
Abstract: We report an interplay between the desorption of intrinsic water and relaxation of polymer chains resulting in an unusual thermomechanical response of a hydrogel, wherein the elastic modulus increases in a certain temperature range followed by a sharp decrease with a further increase in temperature. We establish that, in a hydrogel, the desorption of disparate water types having distinct binding energy affects the consolidation and relaxation behaviour of the matrix, which in turn affects the mechanical properties at different temperature ranges. Using temperature-dependent dielectric relaxation spectroscopy and nanoindentation techniques, the chain dynamics and mechanical properties are investigated.
TL;DR: In this article , the authors present a survey of the state of the art in bioinformatics and biomedicine research, including the following papers: http://www.firstpage
Abstract: First Page