Kasturee Nayak

Bio: Kasturee Nayak is an academic researcher from Indian Institute of Science Education and Research, Kolkata. The author has contributed to research in topics: Chemistry & Polymer chemistry. The author has co-authored 1 publications.

Crosslinked polymethacrylate absorbent with phenylalanine and stearate pendants

Abstract: Abstract Herein, we report a new class of oil absorbents via conventional free radical polymerization method to prepare polymethacrylate gels with a range of crosslinking density having both phenylalanine and stearate moieties in the gel matrix. Analogue crosslinked gel was also synthesized with only stearate pendants without phenylalanine. Solvent absorbing capacity of gels was studied in various solvents with different dielectric constants. The mechanical property and morphology of the absorbents were studied by rheological method and field emission scanning electron microscopy, respectively. Modulation of porosity, absorption capacity and mechanical property of the absorbent were achieved with the variation of crosslinking density. The side chain pendants in the absorbent played an important role toward the solvent uptake capabilities. The absorbent readily can uptake 66 times chloroform and 14 times petrol of its dry weight at room temperature. Overall, the solvent uptake capacity of a new class of absorbents was well studied in this report. Graphical Abstract

Morphological transitions of micelles induced by the block arrangements of copolymer blocks: dissipative particle dynamics simulation.

Abstract: Polymer micelles with distinct morphologies and unique microphase separation microstructures can exhibit different properties and functions, holding great promise for a range of biomedical applications. In the current work, the topological effects of grafted triblock copolymers on the morphologies and microphase separation microstructures of micelles, including block arrangements and grafting arrangements of hydrophobic side chains, are systematically studied. Using common copolymer components of typical drug carriers, micelles with interesting geometries are achieved, such as raspberry, multicompartment, ellipsoidal and dumbbell shapes, in which the relationship between micelle morphology and copolymer topology is verified. With further exploration of the grafting position and amount of hydrophobic side chains, the microstructure influencing mechanism of copolymer micelles in self-assembly is discussed. The block arrangements of hydrophobic side chains determine the configurations of copolymers (zigzag/bridge) inside micelles, which in turn affect the morphological transitions (from spherical to ringed short-rods and then to cylinders) and the size of the hydrophobic ring, which further gradually change into hydrophobic cage. This study provides insight into the microstructure of hydrophobic side chain grafted copolymer micelles and further helps to understand the mechanism of controlling the morphology of micelles, which might be useful to guide the molecular design and experimental preparation of micelles with controllable morphology for drug encapsulation and delivery.

Effect of the N-Alkyl Side Chain on the Amide-Water Interactions.

Abstract: Amide-water interactions influence the structure and functions of amide-based systems, such as proteins and homopolymers. In particular, the N-alkylation of the amide unit appears to play a critical role in defining the interactions of the amide group. Previous studies have linked the thermal behavior of amide-based polymers to the nature of their N-alkyl side chain. However, the connection between the chemical structure of the N-alkyl and the hydration of the amide remains elusive. In this study, the solvation structure and dynamics of amides, having differing N-alkyl groups, are investigated using a combination of linear and nonlinear infrared spectroscopies and computational methods. Interestingly, the dynamics of the amide local environment do not slow down as the N-alkyl side chain becomes bulkier, but rather speeds up. Computational calculations confirm the hydration dynamics and assign the effect to smaller amplitude and faster rotations of the bulkier group. It is also observed experimentally that the hydrogen-bond making and breaking between water and the amide carbonyl do not directly relate to the size of the N-alkyl side chain. The bulkier N-isopropyl substituent presents significantly slower chemical exchange dynamics than smaller chains (ethyl and methyl), but the two small groups do not present a major difference. The hydrogen-bond making and breaking disparities and similarities among groups are well modeled by the theory demonstrating that the N-alkyl group affects the amide hydration structure and dynamics via a steric effect. In summary, the results presented here show that the size of the N-substituted alkyl group significantly influences the hydration dynamics of amides and stress the importance of considering this effect on much larger systems, such as polymers.

Side-chain amino acid-based macromolecular architectures

Abstract: Abstract Amino acids, the natural building blocks of life, are highly functional small molecules with chirality and important catalytic properties. Imparting the exquisite properties of amino acids into the macromolecules allows us to prepare unique, well-defined, biocompatible, functional, and tailorable materials. They exhibit stimuli responsiveness, tunable optical characteristics, enhanced thermal, mechanical, and biological properties with desired cell-materials interactions. Considering the salient features and diverse applications of side-chain amino acid-containing polymers, in this feature article, we present a concise highlight on the recent trends (2015–present) of the synthesis and utilization of pendant amino acid-based polymeric architectures. This article covers the synthesis of different classes of side-chain amino acid-derived polymeric architectures, and their recent utilization in drug and gene delivery, antibacterial activity, anti-fouling activity, heavy metal ion sensing, tissue engineering, etc. We hope that this study will provide a comprehensive outline of key aspects associated with the construction of functional ‘bio-inspired’ polymeric materials with desired characteristics, and their enhanced potential applications. Graphical Abstract