Highly porous, fast responding acrylamide hydrogels through emulsion polymerization using coconut oil

Abstract

AbstractConventional acrylamide hydrogel exhibits a slow swelling rate which limits its potential for novel applications. It is a formidable challenge to increase the rate of swelling and if addressed successfully, this paves new paths for significant advanced applications. Fast responding polyacrylamide hydrogels with microporous structures and an interconnected network of capillary channels have been successfully synthesized by free radical emulsion-templated polymerization (a 2.5 m acrylamide monomer solution was crosslinked with 1% N,N-methylenebisacrylamide using 5% potassium persulfate as the initiator). Virgin coconut oil (70% v/v) was used as the pore forming agent, which was dispersed in the aqueous monomer solution by using 5% non-ionic surfactant (Tween 80®). Developed porous acrylamide hydrogel displayed approximately 600 wt% water absorptivity compared to the dry weight of the sample in 15 s at 30°C. Swelling ratio and scanning electron microscopy studies uncovered the characteristic microporous structure of the hydrogel. Pores of the hydrogel are interconnected to form capillary channels and thus they are responsible for the higher swelling rate of the hydrogel.