(463a) Multiblock Ionomers for Membrane Applications

The water-energy nexus represents the confluence of two pressing engineering challenges facing todayâ??s generation. The demand for clean and potable water continues to increase with the expansion of the global population and the rapid industrialization of developing nations. Correspondingly, new technologies to harvest, store, and discharge the energy required for the production of this valuable resource are critical. Membranes prepared from block polymers are useful as designer materials for both of these applications. For example, block polymers microphase separate to form task-specific phases: one that imparts mechanical strength and the other facilitates ion, electron, or water transport. Ionomers are increasing in popularity based on recent work that highlights their stable and unique morphologies, tailorable ionic conductivity, and high water flux with good salt selectivity. This presentation will highlight work from our lab on membranes fabricated from imidazolium-based triblock copolymers prepared using polymerizable ionic liquids or post-polymerization functionalization strategies for energy applications. Specifically, the influence of (i) charge placement and density in the central and outer blocks; (ii) thermomechanical properties; (iii) ionic liquid incorporation; and (iv) chemical composition of the cation and anion on the properties of imidazole-containing polymers will be discussed. Additionally, recent work has utilized these same materials for salt-selective water purification membranes. The structure-property-diffusion relationships that have been developed contribute toward a better understanding of the interplay between polymer morphology, water and salt sorption and transport characteristics, and thermomechanical properties.