Reversible White-Light-Driven Photochromic Polymer Hydrogels with High Stretchability and Adhesiveness
Yongqi Liu, Jingtao Jiang, Xiuyu Huang, Jingzhi Tang, Qiuli Tan, Yang Chen, Youwei Xiao, Xiaoli Wu, Gengsheng Weng
Abstract
Photochromic materials that reversibly change color by light stimulus are of interest for developing sensors and optoelectronics. A design of Ag + -containing photochromic polymer hydrogel showing reversible photochromism, high stretchability, and high adhesiveness is reported. The polymer hydrogel is fabricated using the Ag + /ammonium persulfate (APS) fast gelation system, which initiates the fast gelation of the acrylic acid (AA) and 3-iminodiacetate-2-hydroxypropyl methacrylate (IDHPMA) aqueous solution. The iminodiacetate (IDA) ligands from the copolymer bind with Ag + ions to form Ag + –IDA coordination cross-links, contributing to the high stretchability of the hydrogel. The Ag + –IDA complexes also impart a high adhesion performance to the hydrogel through the formation of M n + –IDA complexes on various metal surfaces. The Ag + ions in the hydrogel undergo a reversible transition between the ionic and Ag nanoparticle states when subjected to switchable white-light irradiation and incubation in the dark. It is demonstrated that this photochromic hydrogel was suitable for photopatterning with a controllable storage time. This photochromic hydrogel illustrates a pathway to make soft wearable devices for controllable information storage and anticounterfeiting, where high stretchability and adhesiveness are required.