UV-Induced Photochromic Macrofibers Derived from Bacterial Cellulose

The emergence of photochromic fibers has created numerous opportunities in the realm of intelligent textiles and functional materials. However, commercially accessible photochromic fibers are predominantly produced from petroleum-based polymers, which contradicts the current emphasis on sustainability and minimizing carbon emissions. In this work, eco-friendly and fast-reversible photochromic bio-based bacterial cellulose (BC) macrofibers that are combined with 2,2,6,6-Tetramethylpiperidine-1-oxy (TEMPO) -oxidized BC (TOBC) nanofibers and spirooxazine-based photochromic microcapsules (PM) through amide reaction via a simple wet spinning strategy, are developed. The findings suggest that the highest breaking strength of the resulting macrofiber is attained at a PM concentration of 0.2 wt.%, reaching 1.51 cN/dtex, which is 14% greater than that of pure TOBC macrofibers produced. Prepared macrofibers with photochromic properties demonstrate fast response times of just 1 s, durability, and reversible color-changing characteristics when stimulated by ultraviolet (UV) light in the 200-400 nm range. As a proof-of-concept, UV-induced color-changing flowers and patterned textiles are demonstrated by the macrofiber integrated with normal yarns. In conclusion, these innovative bio-based polymer fibers can shine new light into the development of a new generation of anti-counterfeiting and fashion textiles.