KCS

Polymer microgels which have a network structure swollen in a solvent are an important class of soft matter materials with variety of potential applications including drug delivery vehicles, sensors, photonic crystals and etalons, microreactors, cell culture media, and separation and purification technologies. Nanofibrillar hydrogels shows interesting properties such as nonlinear viscoelastic behavior, good transport due to large pore size and thermal stability. Particularly, rod-like cellulose nanocrystals (CNC), one of nature-derived filament-like nanoparticles, are attractive building blocks for hydrogel assembly with their surface functionalities and the ability to form cholesteric (Ch) liquid crystalline phase. Recently, we reported nanofibrillar, composite stimulus-responsive CNC-derived microgels with a Ch structure. Microgels with a narrow size distribution were prepared by microfluidic emulsification, followed by the photopolymerization of the precursor droplets. The spherical confinement of CNC led to the liquid crystalline morphology altered from the spherical concentric to the bipolar planar Ch structure by reducing the droplet dimensions. The microgels exhibited collective properties of CNCs and polymer hydrogels. The stimulus-responsive nature of the microgels was governed by the polymer component and was evidenced by tuning the microgel size and pitch at varying ionic strength and temperature of the ambient medium. The microgels exhibited catalytic performance in a hydrolysis reaction and were used for the in situ synthesis of plasmonic AgNPs. The resulting AgNP-laden microgels exhibited catalytic activity in a reduction reaction. In this presentation, design, synthesis, and performance of the composite microgels for catalytic activities will be discussed.