Double Lock Label Based on Thermosensitive Polymer Hydrogels for Information Camouflage and Multilevel Encryption

作者：Dongyang Lou, Yujing Sun, Jian Li, Yuanyuan Zheng, Zhipeng Zhou, Jing Hua Yang, Chuxuan Pan, Zhikun Zheng, Xudong Chen, Wei Liu · 发表于：Angewandte Chemie International Edition · 年份：2022 · DOI：10.1002/anie.202117066 · 被引用次数：140 · 研究领域：Luminescence and Fluorescent Materials、Polydiacetylene-based materials and applications、Photochromic and Fluorescence Chemistry

Abstract Developing extra safety encryption technologies to prevent information leakage and combat fakes is in high demand but is challenging. Herein, we propose a “double lock” strategy based on both lower critical solution temperature (LCST) and upper critical solution temperature (UCST) polymer hydrogels for information camouflage and multilevel encryption. Two types of hydrogels were synthesized by the method of random copolymerization. The number of −CO−NH2 groups in the network structure of the hydrogels changed the enthalpic or entropic thermo‐responsive hydrogels, and ultimately precisely controlled their phase transition temperature. The crosslink density of the polymer hydrogels governs the diffusion kinetics, resulting in a difference in the time for their color change. The combination of multiple LCST and UCST hydrogels in one label realized information encryption and dynamic information identification in the dimensions of both time and temperature. This work is highly interesting for the fields of information encryption, anti‐counterfeiting, and smart responsive materials.