Synthesis of temperature-sensitive poly(N-isopropylacrylamide) hydrogel with improved surface property

A new PNIPA hydrogel was synthesized by carrying out the polymerization in the gelated corn starch aqueous solution. This PNIPA hydrogel has an improv ed surface property and does not form the disadvantageous bubbles during th e shrinking process. This change is due to the hydrogen bonds between the c orn starch and the hydrophilic side groups of the PNIPA chains, which let t he starch act as the long graft-like chains of the PNIPA hydrogel. During t he reswelling process, this PNIPA hydrogel exhibits a sigmoidal swelling pa ttern. This hydrogel with improved surface property may be very useful for the potential applications of the temperature-sensitive hydrogel. (C) 2000 Academic Press.