Stimuli responsiveness in polymer design is providing basis for diversely new and advanced materials that exhibit switchable porosity in membranes and coatings, switchable particle formation and thermodynamically stable nanoparticle dispersions, polymers that provide directed mechanical stress in response to intensive fields, and switchable compatibility of nanomaterials in changing environments. The incorporation of ionic liquid monomers has resulted in many new polymers based on the imidazolium group. These polymers exhibit all of the above-articulated material properties. Some insight into how these anion responsive polymers function has become empirically available. Much opportunity remains for extending our understanding as well as for designing more refined stimuli-responsive materials.