Multi-Hydration Induced Zwitterionic Hydrogel with Open Environment Stability for Chemical Sensing

Hydrogels with open environment stability are of great significance in the fields of microelectronics, organ regeneration, and hydrogel-based sensors. Although a series of strategies for exploring highly robust hydrogels have been proposed, it is still challenging to improve environmental stability while maintaining the original dispersed medium feature. Here, 1-vinyl-3-butylimidazolium (VBIM) and acrylic acid (AA) are used as the anionic and cationic monomers to prepare zwitterionic hydrogels through the thermal initiation polymerization. The prepared PAA-IL (polyacrylic acid- co -ionic liquid) hydrogel forms a large number of multi-hydration, including hydrogen bonds and ion-dipole interactions with water to inhibit the freezing and volatilization of water, and it possesses good structural stability due to the formation of ion bond self-association through interchain charge interaction. The robust stability of the chemical sensor with PAA-IL hydrogels as the substrate at different pH and temperature verifies the validity of the proposed design strategy. It is expected that the present zwitterionic hydrogel design strategy would shine a light on the exploration of environment-stable hydrogels and hydrogel-based chemical sensors.