Two-dimensional tungstate nanosheets for constructing novel photochromic hydrogel with ultrahigh flexibility

A hydrogel possessing interesting photochromic behaviors was developed by in situ ultraviolet (UV) irradiation-assisted polymerization of an aqueous solution of N-isopropylacrylamide monomer in the presence of cesium tungstate nanosheets. By this process, a hierarchical porous network structure was finely constructed while showing ultrahigh flexibility and retaining the photochromic properties of the cesium tungstate nanosheets. The nanocomposite hydrogel with its excellent photochromic properties and ultrahigh flexibility will have great applications in flexible photochromic devices.269