Transparency and AIE tunable supramolecular polymer hydrogel acts as TEA-HCl vapor controlled smart optical material

Stimuli-responsive optical materials attract lots of attention due to their broad applications. Herein, a novel smart stimuli-responsive supramolecular polymer was successfully constructed using a simple tripodal quaternary ammonium-based gelator (TH). TheTHself-assembles into a supramolecular polymer hydrogel (TH-G) and shows aggregation-induced emission (AIE) properties. Interestingly, the transparency and fluorescence of theTH-Gxerogel film (TH-GF) could be reversibly regulated by use of triethylamine (TEA) and hydrochloric acid (HCl) vapor. When alternately fumed with TEA and HCl vapor, the optical transmittance of theTH-GFwas changed from 8.9% to 92.7%. Meanwhile, the fluorescence of theTH-Gshows an ON/OFF switch. The reversible switching of the transparency and the fluorescence of theTH-GFis attributed to the assembly and disassembly of the supramolecular polymerTH-G. Based on these stimuli-response properties, theTH-GFcould act as an optical material and shows potential applications as smart windows or fluorescent display material controlled by TEA and HCl vapor.