Poly(N-isopropylacrylamide)-based vertically sandwichtyped hydrogel with fast temperature-response speed and its controlled-release characteristics

A novel poly(N-isopropylacrylamide)-based sandwich-typed hydrogel, which was featured with both ends of linear poly(N-isopropylacrylamide) (PNIPAM) chains being grafted onto cross-linked PNIPAM chains, was successfully prepared in a three-step process by a method of sequential synthesis. The proposed hydrogel displays faster and hydration/dehydration dynamic response to temperature cycling owing to linear PNIPAM chains to form big-pore structure. This work may lead to high attraction for targeting drug delivery systems, polymeric pump, sensors and so on.