Advanced functional photochromic wearables with fast photo-responsivity, long color-retention, and multi-environmental stability

Smart photochromic wearables have demonstrated attractive prospects in many emerging fields. However, their lower functional performance limits their applications. Herein, we have fabricated a novel photochromic wearable fabric via covalent grafting and chemical isolation technique grafting WO3 nanoflowers onto cellulose. In the charming system, exceptional photochromic properties of WO3 serve as the color-changing material. Besides, incorporated potassium persulfate as a fast-fading reagent is capable of slow oxygen release upon heating. These combined components give the photochromic fabric a rapid response time of 2 s, a fading time of 5 min, and an unprecedented long color-retention (>7 days). Moreover, this photochromic fabric exhibits outstanding rewritability (100 cycles) and exceptional water resistance, maintaining superb photochromic performance even after undergoing standard washing (50 cycles). Moreover, the activation barriers to the photochromic mechanism for the minimum energy pathway were calculated, which provides a theoretical basis for hydrophobic design. The fabric not only imparts water and oil repellence and antifouling properties but also has chemical stability in multi-environments. Notably, the fabrication process is cost-effective, environmentally friendly, and amenable to large-scale production. Such fabrics hold tremendous promise in household products, public facilities and wearable healthcare technologies.