Deepa K. Baby

Bio: Deepa K. Baby is an academic researcher from Rajagiri. The author has contributed to research in topics: Copolymer & Self-healing hydrogels. The author has an hindex of 5, co-authored 8 publications receiving 67 citations. Previous affiliations of Deepa K. Baby include Mahatma Gandhi University & St. Joseph's College, Devagiri.

Toughening of Epoxy Thermoset with Polystyrene-block-polyglycolic Acid Star Copolymer: Nanostructure–Mechanical Property Correlation

Abstract: A novel amphiphilic polystyrene-block-polyglycolic acid three-arm star copolymer (PS-b-PGA)3 was incorporated in epoxy thermoset to show reaction-induced microphase separation. The diblock copolymer was prepared by atom-transfer radical polymerization followed by chain end modification, and toward the end ring-opening polymerization was utilized to attach the polyglycolic acid moiety. The formation of polystyrene-block-polyglycolic acid was confirmed by using Fourier transform infrared analysis, gel permeation chromatography, and 1H NMR. The microphase separation of block copolymer resulted in the formation of ordered nanodomains in the epoxy thermoset. It was found that the block copolymer in epoxy thermoset displayed reaction-induced microphase separation behavior as evidenced by transmission electron microscopy, scanning electron microscopy, and atomic force microscopy. The tensile strength and the toughness of the thermoset were increased by the incorporation of PGA, which has high glass transition an...

Poly(N‐isopropylacrylamide) hydrogel: Effect of hydrophilicity on controlled release of ibuprofen at different pH

Abstract: Stimuli-sensitive drug delivery systems (DDSs) have attracted considerable attention in medical and pharmaceutical fields; thermo-sensitive DDS dealing with poly(N-isopropylacrylamide) (PNIPAM) have been widely studied. Hydrogels composed of temperature-sensitive NIPAM and biocompatible and pH-sensitive maleic acid (MAc) were synthesized by sedimentation polymerization. Experiments on drug release from the crosslinked NIPAM-co-MAc hydrogel loaded with ibuprofen into different pH buffer solutions were successfully carried out at temperature swing between 25 and 40°C. The in vitro release studies have showed that the release rate depended on acidity or basicity (polarity) of the medium and the gel and swelling ratio of the gel network as a function of the environmental pH and temperature. The SEM image of the dry bead gave more insight into the surface architecture and the thermal studies shine light on the decomposition pattern and glass transition temperature of the gel. The mechanism of the drug release was discussed in relation to the diffusion rate and the abrupt change in the pH of the medium. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Rheology of hydrogels

Abstract: Hydrogel is a general term used for water swollen and porous materials of polymeric, protein, peptidic, colloidal, surfactant, or lipid origin. Hydrogels are a mainstay in the food and pharmaceutical industries but are also increasingly finding applications in areas such as biosensing, microfluidics, drug delivery, and tissue engineering. Rheology is an appropriate method for characterizing hydrogel mechanical properties since it is quick, sensitive, requires small sample sizes, and is revealing of differences in architecture such as degree of cross-linking, proximity of the glass transition, structural homogeneity/heterogeneity and molecular weight. In this chapter we are discussing various aspects of rheology of hydrogels.

Stimulus-responsive hydrogels: Theory, modern advances, and applications

Abstract: Over the past century, hydrogels have emerged as effective materials for an immense variety of applications. The unique network structure of hydrogels enables very high levels of hydrophilicity and biocompatibility, while at the same time exhibiting the soft physical properties associated with living tissue, making them ideal biomaterials. Stimulus-responsive hydrogels have been especially impactful, allowing for unprecedented levels of control over material properties in response to external cues. This enhanced control has enabled groundbreaking advances in healthcare, allowing for more effective treatment of a vast array of diseases and improved approaches for tissue engineering and wound healing. In this extensive review, we identify and discuss the multitude of response modalities that have been developed, including temperature, pH, chemical, light, electro, and shear-sensitive hydrogels. We discuss the theoretical analysis of hydrogel properties and the mechanisms used to create these responses, highlighting both the pioneering and most recent work in all of these fields. Finally, we review the many current and proposed applications of these hydrogels in medicine and industry.

Novel emulsions stabilized by pH and temperature sensitive microgels

Abstract: Surfactant-free oil-in-water emulsions prepared with temperature and pH sensitive poly(N-isopropylacrylamide)(PNIPAM) microgel particles offer unprecedented control of emulsion stability.

Photophysics Modulation in Photoswitchable Metal–Organic Frameworks

Abstract: In this Review, we showcase the upsurge in the development and fundamental photophysical studies of more than 100 metal-organic frameworks (MOFs) as versatile stimuli-responsive platforms. The goal is to provide a comprehensive analysis of the field of photoresponsive MOFs while delving into the underlying photophysical properties of various classes of photochromic molecules including diarylethene, azobenzene, and spiropyran as well as naphthalenediimide and viologen derivatives integrated inside a MOF matrix as part of a framework backbone, as a ligand side group, or as a guest. In particular, the geometrical constraints, photoisomerization rates, and electronic structures of photochromic molecules integrated inside a rigid MOF scaffold are discussed. Thus, this Review reflects on the challenges and opportunities of using photoswitchable MOFs in next-generation multifunctional stimuli-responsive materials while highlighting their use in optoelectronics, erasable inks, or as the next generation of sensing devices.

Multifunctionality in Epoxy Resins

Abstract: Epoxy resin will continue to be in the forefront of many thermoset applications due to its versatile properties. However, with advancement in manufacturing, changing societal outlook for the chemic...