Encapsulation of Poly(N-Isopropyl Acrylamide) in Silica: A Stimuli-Responsive Porous Hybrid Material That Incorporates Molecular Nano-Valves

Abstract

Incorporation of a smart polymer into a silica matrix can lead to smart membranes, it is demonstrated here. Polymer–silica membranes were supported on porous centrifugal filters (see Figure), the encapsulated polymer molecules acting as “nano-valves”. Permeation experiments with aqueous solutions of poly (ethylene glycol) show that the membranes function as thermally switchable molecular filters.