Bioinspired Anisotropic Hydrogel Actuators with On–Off Switchable and Color‐Tunable Fluorescence Behaviors

• Published in: Advanced functional materials 2018-02, Vol.28 (7), p.n/a
• Main Authors: Ma, Chunxin, Lu, Wei, Yang, Xuxu, He, Jiang, Le, Xiaoxia, Wang, Li, Zhang, Jiawei, Serpe, Michael J., Huang, Youju, Chen, Tao
• Format: Article
• Language: English
• Subjects: anisotropic structures; Biomimetic materials; Color; color‐changing materials; Deformation mechanisms; Fluorescence; Hydrogels; Isopropylacrylamide; Light irradiation; macroscopic supramolecular assembly; Materials science; Polyethyleneimine; polymeric hydrogel actuators; shape deformation; Smart materials
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201704568

An effective approach to develop a novel macroscopic anisotropic bilayer hydrogel actuator with on–off switchable fluorescent color‐changing function is reported. Through combining a collapsed thermoresponsive graphene oxide‐poly(N‐isopropylacrylamide) (GO‐PNIPAM) hydrogel layer with a pH‐responsive perylene bisimide‐functionalized hyperbranched polyethylenimine (PBI‐HPEI) hydrogel layer via macroscopic supramolecular assembly, a bilayer hydrogel is obtained that can be tailored and reswells to form a 3D hydrogel actuator. The actuator can undergo complex shape deformation caused by the PNIPAM outside layer, then the PBI‐HPEI hydrogel inside layer can be unfolded to trigger the on–off switch of the pH‐responsive fluorescence under the green light irradiation. This work will inspire the design and fabrication of novel biomimetic smart materials with synergistic functions. A macroscopic anisotropic bilayer hydrogel actuator integrating complex shape‐changing and fluorescent color‐changing functions is explored. The thermoresponsive shape deformation can trigger the on–off switch of the pH‐responsive fluorescence change, which will inspire the design of novel biomimetic smart materials with synergistic functions.