Regulating Aggregated Structures in Organohydrogels for On-Demand Information Encryption

Abstract

As one of the most promising candidates for dynamic information storage, intelligent gels with tunable optical properties under external stimuli have received great attention. The implementation of transparency variation for information display is a favorable and versatile strategy but still faces the challenge of on-demand encryption-decryption. Herein, an optical tunable organohydrogel is prepared, which has interpenetrating heterogeneous networks consisting of hydrophilic poly(N,N-dimethylacrylamide) (PDMA) and hydrophobic polyoctadecyl methacrylate (PSMA). The long alkane side chains of PSMA endow the organohydrogel with the capacity of crystallization-melting transitions under the stimulus of heat, accompanied by transparent-opaque switching. In addition, the variations of transparency can also be achieved by water-induced hydrophobic association and microphase separation, resulting from the unique heterogeneous networks of the organohydrogel. Based on the abovementioned two aggregated structures, various pieces of information can be loaded on the organohydrogel by light writing or water printing with the assistance of masks. The coded information can be encrypted and decrypted by solvent replacement and temperature switching. This elaborately designed organohydrogel can act as an effective communication platform with an improved security level and ignite the sparks of developing novel information storage materials.