Multi‐Level Information Encryption/Decryption of Fluorescent Hydrogels Based on Spatially Programmed Crystal Phases

Abstract The growing urgence of information protection promotes continuously the development of information‐encryption technique. To date, hydrogels have become an emerging candidate for advanced information‐encryption materials, because of their unique stimulus responsiveness. However, current methods to design multi‐level information‐encrypted hydrogels usually need sophisticated chemistry or experimental setup. Herein, a novel strategy is reported to fabricate hydrogels with multi‐level information encryption/decryption functions through spatially programming the polymorphic crystal phases. As homocrystalline and stereocomplex crystal phases in fluorescent hydrogels have different solvent stabilities, the transparency and fluorescence of the hydrogels can be regulated, thereby enabling the multi‐level encryption/decryption processes. Moreover, the structural origins behind these processes are discussed. It is believe that this work will inspire future research on developing advanced information‐encryption materials upon programming the polymer crystal structure.