Chameleon-inspired iridescent structural color textiles with reversible multiple stimulus-responsive functions

Over the past millions of years, plants and animals in nature have evolved complex microscopic structures, giving them vivid colors and camouflage that can deceive predators. Among the abundant sources of natural coloration, structural color is dominant in many creatures, which is created by the interaction between light and the nanostructures. Here, inspired by the natural structural color, we report an iridescent cotton fabric (ICF) with reversible multiple stimulus-responsive functions. Cellulose nanocrystal (CNC) could self-assemble into structural color nanostructure on the cotton fabric surface. And the flexible ICFs with tunable structural colors could be achieved by adding different proportions of glucose. Surprisingly, we proposed a novel and eco-friendly method to realize gradient structural colors by changing the self-assembly way of the CNCs onto CF surface without adding superfluous additives. Furthermore, due to the response characteristics of CNC to water molecules, the ICF is endowed with reversible behaviours including anti-counterfeiting, relative humidity sensing and water content detection functions, which make ICF become a smart textile that could be applied in many fields. Taken together, the presented findings are expected to pave the way towards the incorporation of CNCs in textile coloration with the researches focusing on the smart textile materials.