Li Xinkai, Qiu Xiaoyan, Yang Xin, Zhou Peng, Guo Quanquan, Zhang Xinxing
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu, 610065, China.
Max Planck Institute of Microstructure Physics, 06120, Halle (Saale), Germany.
Adv Mater. 2024 Sep;36(36):e2407170. doi: 10.1002/adma.202407170. Epub 2024 Jul 8.
Ubiquitous anti-counterfeiting materials with a rapidly rising annual consumption (over 10 m) can pose a serious environmental burden. Biobased cellulosic materials with birefringence offer attractive sustainable alternatives, but their scalable solvent-free processing remain challenging. Here, a dynamic chemical modification strategy is proposed for multi-modal melt-processing of birefringent cellulosic materials for eco-friendly anti-counterfeiting. Relying on the thermal-activated dynamic covalent-locking of the spatial topological structure of preferred oriented cellulose, the strategy balances the contradiction between the strong confinement of long-range ordered structures and the molecular motility required for entropically-driven reconstruction. Equipped with customizable processing forms including mold-pressing, spinning, direct-ink-writing, and blade-coating, the materials exhibit a wide color gamut, self-healing efficiency (94.5%), recyclability, and biodegradability. Moreover, the diversified flexible elements facilitate scalable fabrication and compatibility with universal processing techniques, thereby enabling versatile and programmable anti-counterfeiting. The strategy is expected to provide references for multi-modal melt-processing of cellulose and promote sustainable innovation in the anti-counterfeiting industry.
年消费量迅速增长（超过1000万）的无处不在的防伪材料可能会造成严重的环境负担。具有双折射的生物基纤维素材料提供了有吸引力的可持续替代品，但其可扩展的无溶剂加工仍然具有挑战性。在此，提出了一种动态化学改性策略，用于对双折射纤维素材料进行多模态熔融加工，以实现环保防伪。该策略依靠热激活的动态共价锁定优选取向纤维素的空间拓扑结构，平衡了长程有序结构的强限制与熵驱动重建所需的分子运动性之间的矛盾。这些材料具备包括模压、纺丝、直接喷墨书写和刮刀涂布在内的可定制加工形式，展现出宽广的色域、自愈效率（94.5%）、可回收性和生物降解性。此外，多样化的柔性元件有助于可扩展制造以及与通用加工技术的兼容性，从而实现多功能和可编程防伪。该策略有望为纤维素的多模态熔融加工提供参考，并促进防伪行业的可持续创新。
