(129b) Development of Poly(ionic liquid) Ionogels for Electroactive Polymer Application.

Poly(ionic liquids) (PILs) are a special type of strong polyelectrolyte that combine the diverse functionality and unique properties of ionic liquids (ILs) with the mechanical stability, long-range ordering, and processability of polymers. These materials are particularly attractive in electrochemical applications, such as solid-state batteries and flexible electronics, due to their intrinsic ion conductivity, good thermal stability, non-flammability, and wide electrochemical windows. In recent years, PILs have also shown potential for use in ionic electroactive polymers (IEAPs) systems. Ionic electroactive polymers (IEAP) are materials that can mechanically respond, or actuate, under an applied electrical voltage due to ion migration within the polymer system. They are typically composed of a polymer matrix (e.g. Nafion or PVDF) containing a liquid electrolyte, aqueous salt solution (hydrogel) or ionic liquids (ionogels), sandwiched between two conductive electrodes. PILs are ideal polymer matrices for ionogels-based actuators due to their high compatibility with ionic liquids, resulting in gels with minimal IL leakage and longer periods of operational stability. However, the use of PIL polymers in electroactive actuators is still in its infancy. In this work, PIL homopolymers and block copolymers were synthesized through living radical polymerization techniques and then combined with a select ionic liquid to form ionogels. The synthesized polymers were characterized for their chemical and molecular weight characteristics through GPC, NMR, and FITR. The polymer glass transition temperature and thermal stability was evaluated with DSC and TGA respectively. EIS was utilized to measure ion conductivity of the polymers and ionogels. The mechanical properties of the materials were examined. Preliminary investigations into the electroactive actuation behavior of select ionogels was investigated at low voltages (<5 V) by sandwiching the solid electrolyte membranes between two layers of electrode material.