Block copolymer ion gels for gas separation

Carbon dioxide removal from light gases (eg. N$_{2}$, CH$_{4}$, and H$_{2})$ is a very important technology for industrial applications such as natural gas sweetening, CO$_{2}$ capture from coal-fire power plant exhausts and hydrogen production. Current CO$_{2}$ separation method uses amine-absorption, which is energy-intensive and requires frequent maintenance. Membrane separation is a cost-effective solution to this problem, especially in small-scale applications. Ionic liquids have recently received increasing interest in this area because of their selective solubility for CO$_{2}$ and non-volatility. However, ionic liquid itself lacks the persistent structure and mechanical integrity to withstand the high pressure for gas separation. Here, we report the development and gas separation performances of physically crosslinked ion gels based on self-assembly of ABA-triblock copolymers in ionic liquids. Three different types of polymers was used to achieve gelation in ionic liquids. Specifically, a triblock copolymer ion gel with a polymerized ionic liquid mid-block shows performances higher than the upper bound of well-known ``Robeson Plot'' for CO$_{2}$/N$_{2}$.