Abstract
Ionic liquids are ambient temperature molten salts that have attracted considerable attention, because of their unique property such as negligible volatility and thermal stability. In this review, progress, challenges, and opportunities of new polymer gels swollen by ionic liquids, named “ion gels”, are demonstrated. To form polymer networks in ionic liquids, we focus on the self-assembly of amphiphilic block copolymers in ionic liquids, based on micro-phase separation. The obtained ion gels exhibit high ionic conductivity, comparable with neat ionic liquids, together with soft solid consistency. We show here an example of the application as polymer electrolyte of ionic polymer actuators, combined with composite carbon electrodes. Moreover, stimuli-responsive polymers in ionic liquids are proposed. Solubility change of the responsive polymers in ionic liquids can be induced by temperature change and light irradiation. Block copolymers containing stimuliresponsive segments can realize thermo- and photo-reversible ion-gel formation induced by stimuli-sensitive self-assembly changes. Finally, we demonstrate photo-healable soft materials that can be repaired in response to an optical trigger from damaged states.
