A5026223831- Hydrogels: synthesis, properties, applications
- Advanced Polymer Synthesis and Characterization
- Rheology and Fluid Dynamics Studies
- Polymer Nanocomposites and Properties
- biodegradable polymer synthesis and properties
- Advanced Materials and Mechanics
- Polymer composites and self-healing
- Supramolecular Self-Assembly in Materials
- Polymer crystallization and properties
- VLSI and Analog Circuit Testing
- Electrospun Nanofibers in Biomedical Applications
- Advanced Sensor and Energy Harvesting Materials
- Membrane Separation Technologies
- Fiber-reinforced polymer composites
- Polysaccharides Composition and Applications
- Flame retardant materials and properties
- Luminescence and Fluorescent Materials
- Conducting polymers and applications
- High-Velocity Impact and Material Behavior
- Graphene and Nanomaterials Applications
- Electrostatics and Colloid Interactions
- Advancements in Transdermal Drug Delivery
- Elasticity and Material Modeling
- Surface Modification and Superhydrophobicity
- Advanced Drug Delivery Systems
Mississippi State University
2016-2025
Intel (India)
2022-2024
Georgetown University
2023
University of Mannheim
2023
Professor Jayashankar Telangana State Agricultural University
2023
Stark State College
2019
Vidyasagar University
2018
Indian Institute of Technology Kharagpur
2018
Indian Institute of Engineering Science and Technology, Shibpur
2018
University of Calcutta
2018
The mechanical properties of gels present qualitatively contradictory behavior; they are commonly soft but also notoriously brittle. We investigate the elasticity and fracture behavior swollen polymer networks using a simple experimental method to induce cavitation within gel adapt scaling theories capture observed transition from reversible irreversible deformations as function volume fraction. It is shown quantitatively that depends on fraction an initial defect length scale. use...
Enzymes immobilized on solid supports are increasingly used for greener, more sustainable chemical transformation processes. Here, we microreactors to study enzyme-catalyzed ring-opening polymerization of ε-caprolactone polycaprolactone. A novel microreactor design enabled us perform these heterogeneous reactions in continuous mode, organic media, and at elevated temperatures. Using microreactors, achieved faster higher molecular mass compared using batch reactors. While this focused...
Shear-thickening fluids (STFs) can be subjected to a significant temperature variation in many applications. Polymeric or oligomeric are commonly used as suspending media for STFs. Because the viscosities of polymeric strongly temperature-dependent, large changes profoundly affect shear-thickening responses. Here, effect on behavior four low-molecular-weight glycols/fumed silica suspensions is reported. The dispersed-phase volume fraction, its surface chemistry, and chemical compositions...
Polysaccharide-based hydrogels are being used in a wide variety of applications ranging from tissue engineering to food products due their biocompatibility and the ease gel formation. In real-life applications, can undergo large strain deformation, which may result structural damage leading failure. Here, we report nonlinear rheological properties failure behavior alginate hydrogels, class polysaccharide synthesized via ionic covalent crosslinking. Gels with crosslinks or prepared by...
Carbon quantum dots (CQDs) have potential applications in many fields such as light-emitting devices, photocatalysis, and bioimaging due to their unique photoluminescence (PL) properties environmental benignness. Here, we report the synthesis of nitrogen-doped carbon (NCQDs) from citric acid m-phenylenediamine using a one-pot hydrothermal approach. The environment-dependent emission changes NCQDs were extensively investigated various solvents, solid state, physically assembled PMMA-PnBA-PMMA...
The viscoelastic properties of polymer thin films can have a significant impact on the performance in many small-scale devices. In this work, we use phenomenon based thermally induced instability, termed thermal wrinkling, to measure polystyrene as function geometric confinement via changes film thickness. With application appropriate buckling mechanics model for incompressible and geometrically confined films, estimate stress-relaxation modulus by measuring time-evolved wrinkle wavelength...
We investigate the nonlinear rheology and cavitation phenomena of a strain-stiffening physical gel.
Molecular gels have been investigated over the last few decades; however, mechanical behavior of these self-assembled is not well understood, particularly how materials fail at large strain. Here, we report gelation and rheological a molecular gel formed by self-assembly low weight gelator (LMWG), di-Fmoc-l-lysine, in 1-propanol/water mixture. Gels were prepared solvent-triggered technique, was tracked using Fourier transform infrared (FTIR) spectroscopy shear rheology. FTIR captures...
ABSTRACT Alginate hydrogels are polysaccharide biopolymer networks widely useful in biomedical and food applications. Here, we report nonlinear mechanical responses of ionically crosslinked alginate captured using large amplitude oscillatory shear experiments. Gelation was performed situ a rheometer the rheological investigations on these samples strain‐stiffening behavior for gels as function strain. In addition, negative normal stress observed, which has not been reported earlier any...
Abstract With antibiotic‐resistant bacteria becoming increasingly prevalent, biomaterials capable of targeted, in situ drug delivery are urgently needed. The synthetic polymer Poloxamer 407 (P407) is particular interest due to its thermoreversible gelation. Clinical use P407 typically involves sterilization via autoclaving, but the effects these extreme environmental conditions on hydrogel water content, rheological properties and efficacy as a vehicle remain unknown. aim this study was...
Despite significant interest in molecular gels due to their intriguing structure formation through self-assembly and stimuli-responsive behavior, our understanding of the gel mechanism a low-molecular-weight gelator (LMWG) is incomplete. Here, we report combined experimental computational study on LMWG, di-Fmoc-l-lysine, that has two aromatic moieties multiple hydrogen bond donors acceptors. Gelation various organic solvent-water mixtures was obtained solvent-triggered technique. We show an...
Oppositely charged polyelectrolytes often form polyelectrolyte complexes (PECs) due to the association through electrostatic interactions. Obtaining PECs using natural, biocompatible is of interest in food, pharmaceutical, and biomedical industries. In this work, were prepared from two biopolymers, positively chitosan negatively alginate. We investigate changes structure properties by adding sodium chloride (salt doping) system. The shear modulus can be tuned ∼10 104 Pa changing salt...
Mammalian lung mucus is a complex fluid that displays non-linear viscoelastic responses, strain-stiffening at low-strain and strain-softening large strain values.
Abstract Topological patterns on polymer surfaces can significantly alter and control adhesion. In this study, the effect of surface wrinkles a spherical adhesion has been studied. Surface wrinkling induced by swelling crosslinked polydimethylsiloxane elastomer constrained stiff, thin layer (silicate) is used to produce topographic features various length scales over large curved area. By controlling properties stiff applied strain conditions, varying amplitude wavelength are obtained. The...