Scalable, Fast Light‐Responsive, and Excellent Color‐Retention Fiber‐Based Photochromic Wearables for Sustainable Photo‐Patterning and Information Security Encryption

Abstract Fiber‐based photochromic wearables have attracted growing attention in sustainable photo‐patterning information displays, information security encryption, and optical data recording/storage. Molybdenum trioxide (MoO 3 ) is one of the key photochromic materials that possesses good photochromic performance, nevertheless, it faces considerable challenges in preparing photochromic textiles with stable, scalable, and long color‐retention properties. In this work, a new kind of fiber‐based photochromic wearables is designed and developed by combining cotton fabric with a MoO 3 ‐based self‐adhesive polymer network and long chain silyl group. The prepared photochromic wearable has exhibited excellent fatigue resistance and favorable reversibility (> 40 cycles), rapid light response (reach color saturation with a UV dose of 60 kJ m −2 ), outstanding color retention capability (> 90 days), and desirable biocompatibility (cell viability > 100%). In addition, the prepared photochromic textiles could maintain a fast light response and excellent color retention even after experiencing repeated washing (20 cycles). Moreover, the photo‐patterning photochromic wearables are verified by resisting the deterioration of acid solution, alkali solution, and sweat (pH 2.0–9.0) as well as keeping clear patterns under sunlight irradiation. As a demonstration of the application, fiber‐based photochromic wearables are made and employed for the sustainable applications of rewritable photo‐patterning and information security encryption.