Thermo-responsive poly(N-isopropyl acrylamide) hydrogel with increased response rate

Thermo-responsive poly(N-isopropyl acrylamide) (PNIPAM) has attracted a tremendous focus in medicinal applications because of its responses at physiologically relevant temperatures. Nevertheless, its applications in many other disciplines have been greatly limited owing to long response time of the present hydrogels. On that regard, highly porous and fast responding PNIPAM hydrogels were prepared by emulsion-templated polymerization using virgin coconut oil. Resulted macroporous hydrogel was characterized by swelling studies, FTIR spectroscopy, DSC and SEM. Swelling studies have confirmed that the physically modified hydrogel deswells more than 85% of its total volume of water at equilibrium swollen state in 15 s upon increasing temperature above the volume phase transition temperature (VPTT). This is approximately seven times faster than the response rate of the conventional PNIPAM hydrogel and PNIPAM hydrogels synthesized by many other methods reported in the literature.