Shape Memory Hydrogels with Simultaneously Switchable Fluorescence Behavior.

Realization of shape memory process in polymeric hydrogels at ambient condition is a significant development to shape memory materials. The sound understanding of the dynamic shape memory process is fundamentally important but limited. Here, a novel shape memory hydrogel with simultaneously switchable fluorescence behavior is developed. The hydrogel is prepared by incorporating a pH-responsive fluorescent molecule, perylene tetracarboxylic acid, into chitosan-based hydrogel, and the assembly and disassembly of chitosan chains into microcrystals upon the trigger of pH are applied as reversible crosslinks to achieve shape memory effect. Therefore, the formation and disassociation of microcrystalline chitosan, and the switchable fluorescence performance happen concurrently, which bring convenience to monitoring the shape memory process by fluorescent imaging. Moreover, the erasable fluorescence behavior also gives the hydrogel potential applications in information storage.