Examining ionicity and conductivity in poly(methyl methacrylate) containing imidazolium-based ionic liquids

Ionic liquid (IL) interactions with amorphous polymers or polyelectrolytes attract interests due to their propensity to form ionogels with enhanced viscosity and reduced ionic conductivity when compared to their neat IL. A good understanding on the interactions between polymer and IL is needed to design better IL-based hybrid electrolytes. This study examines the mixtures of IL-polymer electrolytes with relatively low polymer concentration to improve their conductivity. Ion transport properties of three types of imidazolium-based ionic liquids are investigated with the addition of linear poly(methyl methacrylate) (PMMA) homopolymer. Dielectric properties of PMMA/IL mixtures indicated the enhancement of apparent ionicity of ILs, which is attributed to the preferential interactions between PMMA and bis(trifluoromethylsulfonyl)imide (TFSI-) anions. The frequencydependent conductivity data analyzed by the Jonscher universal power law infer that ion-dipole coupling interactions between PMMA and IL help in the solvation and enhance the ionicity by disrupting the cage structure and facilitating the fast ion motions of IL.