(376av) Gas Separation Performance of Polymer-Ionene Hybrids

Ionic liquids (ILs) have been explored as media for membrane-based gas separations, both in supported liquid membrane (SLMs) and polymerized ionic liquid (poly(ILs)) forms. Ionenes are another class of ionic polymers wherein the ionic groups are located directly within the polymer backbone, yet there is very little research focusing on the use of ionenes as gas separation membranes. While many ionenes are relatively simple ammonium salts tethered by long alkyl chains, there are ample opportunities to design much more complex ionenes which are inspired by the other classes of polymer materials such as polyimides, thermally-rearranged (TR) polymers, and polymers of intrinsic microporosity (PIMs). We are investigating the design and synthesis of novel polymer-ionene hybrids derived from structural and functional components typically associated with these high-performance and ultra-high-performance polymer materials. These sophisticated material classes possess distinct advantages and disadvantages, yet there are a number of unique properties and behaviors which may arise from a precise spacing and alternating sequence of multiple types of linkages (i.e. amide-imide) and imidazolium cations along the main chain. Here, we present the design philosophy and development of polymer-ionene hybrids resulting from complex monomer units and the impact of design on gas separation performance.