Substituent-regulated spiropyran/polyurethane fibers with rapid photochromic response and high durability - Jing Li; Ke Liu; Ying Feng; Huiyi Zong; Jinghan Zeng; Xiaohong Liao; Ming Yang; Zhen Wang; Zhen Chen; Changhai Yi; Jin Qian; Kai Wang; et al. (Chemical Engineering Journal, 2026)