High free volume polymeric membranes for CO2 capture: state-of-the-art

Carbon dioxide(CO2) capture has been widely accepted to be a prerequisite strategy to mitigate the increase of CO2 concentration in the atmosphere. Membrane separation has been envisaged to be one of the most promising technologies for CO2 capture due to its small footprint, simple up- and down-scaling, and low impact on the environment. Owing to their extraordinarily high CO2 permeability and moderate CO2 selectivity over other gases, high free volume polymeric membrane materials have been intensively studied for CO2 capture. In the past few years, abundant high free volume polymers have been developed and big progress has been made in this field. Therefore, in this review, starting from CO2 emissions and sources, followed by CO2 transport mechanisms in polymeric membranes, this paper emphasizes reviewing recent research progress in high free volume membrane materials, collecting and analyzing CO2 separation data, as well as discussing the challenges of high free volume polymeric membranes. Furthermore, perspectives on future directions of high free volume polymeric membranes were also proposed.