Thermally Responsive Composite Hydrogel via Self-Assembly for Smart Window Applications

Abstract

A novel thermally responsive hydrogel (TRH) has been demonstrated by confining poly(ethylene oxide), poly(propylene oxide), and poly(ethylene oxide) triblock-copolymer (EPE) molecules into the pores of polymer framework. Aqueous EPE copolymer molecule had a tendency to aggregate to form clusters gradually and precipitated from water when the temperature is above a cloudy point. By adding EPE molecules into the acrylamide (AM) monomer solution, the mixture can be fabricated as uniform and transparent hydrogel via controlled radical polymerization. The polyacrylamide hydrogel is produced with a switchable optical property when subjecting to temperature variation. Such reversible thermally responsive material can be utilized as a functional material for smart window application. Additionally, the thermal responsive hydrogel is an inexpensive material, which is readily applicable as smart windows with significant reduction in material cost.