The increased concentration of CO 2 in the atmosphere is the single most important anthropogenic cause of global warming. Decreasing the release of CO 2 into the atmosphere requires efficient CO 2 capture and separation technologies. Decades of research have been devoted to improving existing gas separation technologies, but there is still an imminent need to find new methodologies given the current course of climate change . Traditional unit operations have the ability to isolate high-purity products, but they have a high carbon footprint due to the high energy requirements. Membrane-based technologies are an attractive alternative because they provide savings in capital and energy-related operating costs, and offer advantages related to the ease of operation and compact environmental footprint . Polymer membranes have been successfully investigated for H 2 recovery, N 2 generation, but there is still a significant opportunity to improve polymer membrane technology for CO 2 separations. Although hundreds of new materials are synthesized each year, most of the commercial membranes used today are from the 1990s, and they rely on a dozen or so common polymer structures. This is largely because the two properties that are important for a membrane material -high flux (permeability) and high gas purity (selectivity) -are inversely correlated. This inverse relationship between gas selectivity and permeability was first examined by Robeson in 1991 and revisited in 2008 for pure homopolymer membranes and is famously known as the Robeson Upper Bound. Since then, there have been considerable efforts in designing polymers that are above the empirically determined upper bound for a given application .