An integrated materials approach to ultrapermeable and ultraselective CO polymer membranes.

Advances in membrane technologies that combine greatly improved carbon dioxide (CO) separation efficacy with low costs, facile fabrication, feasible upscaling, and mechanical robustness are needed to help mitigate global climate change. We introduce a hybrid-integrated membrane strategy wherein a high-permeability thin film is chemically functionalized with a patchy CO-philic grafted chain surface layer. A high-solubility mechanism enriches the concentration of CO in the surface layer hydrated by water vapor naturally present in target gas streams, followed by fast CO transport through a highly permeable (but low-selectivity) polymer substrate. Analytical methods confirm the existence of an amine surface layer. Integrated multilayer membranes prepared in this way are not diffusion limited and retain much of their high CO permeability, and their CO selectivity is concurrently increased in some cases by more than ~150-fold.