A Bio-Inspired and Biomass-Derived Healable Photochromic Material Induced by Hierarchical Structural Design

Utilization of bionics to develop stimuli responsive polymers that can heal damage with excellent restorability is particularly attractive for a sustainable society. Herein, inspired by chameleons, a hierarchical structural design strategy is proposed and illustrated to fabricate a healable photochromic material based on a self-healable polymeric matrix and a finely dispersed photochromic spirooxazine. The self-healable polymeric matrix is fabricated via the integration of multiple hydrogen bonds (H bonds) and covalent cross-links into a biomass-derived elastomer. The dynamic nature and soft characteristics enable the as-prepared elastomer superior extensibility as well as self-healing ability, while the covalent cross-links can assist the reassociation of ruptured H bonds. The representative elastomer exhibits an extensibility of 2600% and toughness of 42.76 MJ m −3 . Furthermore, it shows good self-healing ability with complete recovery of scratch as well as restoration against 1900% of elongation and 24.1 MJ m −3 of toughness after healing at 60 °C for 24 h. This combination of moderate toughness, good self-healing ability, and smart photochromic property in biomass-derived materials should largely improve their applicability, reliability, and sustainability in various materials and devices.