Fossil fuels are essential for meeting power demands in the United States. Increasingly, modern energy conversion systems aim to generate electricity from fossil fuels while keeping CO₂ emissions low, which involves capturing gas before or after combustion. Finding the ideal material to effectively separate and transport CO₂ has proven a challenge, and researchers continue to explore a variety of options.

Microporous polymers have high gas permeability combined with good molecular discrimination, making them attractive as commercial gas separation membranes. However, these generally glassy materials are highly brittle and prone to cracking. NETL’s invention blended one of these promising microporous glassy polymers with a soft rubbery polymer, further improving its CO₂ selectivity against light gases such as N₂ with minimal tradeoff in gas permeability and much improved mechanical flexibility, making it more suitable for use as a thin supported coating.