Dual-response of temperature and humidity asymmetrical cotton fabric prepared based on thiol-ene click chemistry

Smart fabrics that can change functional properties in response to the variable environment are revecing great attention nowadays. In this paper, a dual-responsive of temperature and humidity cotton fabric was prepared by UV-induced thiol-ene click chemical grafting of N-isopropylacrylamide (NIPAAm). Firstly, a thiol-reactive precursor on the surface of cotton was prepared by 3-mercaptopropyltriethoxysilane. Then, NIPAAm was grafted onto one side of the cotton fabric under UV irradiation. This resultant fabric can shrink and recover timely according to environmental change due to the absorption and release of water in the air. The results demonstrated it shrinks under conditions of the temperature above the lower critical solution temperature (LCST) and at low humidity, and recovers when conditions change. The surface morphology and the related properties of the treated fabric were characterized. The reaction mechanism was also analyzed for further understanding of responsive behaviours, and we believe the dual-response of ambient temperature and humidity fabric will be a controllable switch in practical application as a smart fabric.