Halometallate Ionic Liquid Dynamically Regulates Zwitterionic Hydrogels by Synergistic Multiple‐Bond Networks

Abstract Improving the compatibility between high concentration metallic ions and zwitterions to controllable construction of coordination bonds is critical and extremely challenging. Here, a facile and effective strategy to fabricate multifunctional hydrogels by randomly copolymerizing halometallate ionic liquids (ILs) and zwitterions through electron beam irradiation is reported. Introducing metal ions into ILs can balance charges and establish moderate and stable cross‐linked networks with zwitterions. The synergistic effect of coordination bonds and multiple interactions with varying strengths endows hydrogel with outstanding stretchability, compressive strength, rapid response, advanced self‐healing ability, and excellent frost resistance. The multifunctional sensor assembled from hydrogels can timely, accurately, and stably monitor human movement, write anti‐counterfeiting and remotely transmit Morse code signals. Multiple hydrogel sensors are also assembled into a flexible sensor array to track the tactile trajectory and detect spatial distribution of force. Moreover, the obtained hydrogel displays high temperature sensitivity with resistance temperature coefficient of −3.85% °C ⁻¹ at 25–40 °C, which can detect tiny temperature changes (0.1 °C). Interestingly, the processed hydrogel can effectively modulate the transmissivity through salt triggering to achieve patterning. Considering the structural designability of halometallate ILs, this work provides new insights for the development of multifunctional hydrogels.