Complex coacervation of polymerized ionic liquids in non-aqueous solvents

The formation of polyelectrolyte complex coacervates within solutions of two oppositely charged polymers is a topic of great recent interest. Studies to date have focused almost exclusively on polyelectrolyte mixtures in water or aqueous solvent mixtures. In this study, polymerized ionic liquids (PILs) were used to investigate the effects of solvent on complex coacervation in non-aqueous solvents. We constructed phase diagrams of PIL mixtures in non-aqueous solvents via experiments using UV-Vis and quantitative ¹⁹F-NMR spectroscopy, and found a substantial difference between two solvent systems in terms of the salt resistance, i.e., the concentration of added salt where complex coacervates are destroyed. Through these studies we seek to provide insight into the role of dielectric constant and solvent/polymer interactions on complex coacervation.