Photochromic and mechanochromic cotton fabric for flexible rewritable media based on acrylate latex with spiropyran cross-linker

Rewritable materials play a significant role in reducing paper production and consumption, information storage and anticounterfeiting, etc. Rewritable textiles have attained much attention due to the flexibility, easy availability and functionality. How to develop a photochromic and mechanochromic dual-stimuli responsive fabric as a flexible rewritable media or display substrate is still rarely reported. In the present work, we present the rational design and synthesis of stimuli-responsive acrylate latex via emulsion polymerization with a spiropyran cross-linker. Spiropyran was chemically bonded into the polymer network of latex particles. Then cotton fabrics were spraying coated by the latex with different composition and add-on percentage. Writing without ink was carried out to investigate the photochromic and mechanochromic properties of the functionalized cotton fabrics. The functionalized cotton fabric still could change color under writing without ink after soaping for 50 times and light irradiation for 20 cycles. Our developed flexible cotton fabric can be used as a long-term, efficient, and stable rewritable media or flexible display substrate, even in the harsh environment such as washing.