Recent advances in Poly(ionic liquids) membranes for CO2 separation

• Screening poly(ionic liquids) type and their performances were critically reviewed. • The influence of the chemical structure of PILs on membrane performances was discussed. • The PIL-based membranes blend with ILs or porous particles exhibited enhanced CO 2 separation properties. • Different strategies for improving PIL membrane performance were presented. • Future perspectives for PIL membrane development and application were proposed. Developing energy-efficient and environmentally friendly technologies are particularly crucial for CO 2 separations from flue gas, natural gas, and syngas. Membranes made from functionalized poly(ionic liquids) (PILs) have recently attracted great attention for gas separations, but few systematic reviews from the material preparation to their applications have been reported. Therefore, the latest progress in the preparation of different types of PIL-based membranes such as pure PIL membranes, PIL copolymer membranes, PIL/IL composite membranes, and PIL-based mixed matrix membranes (MMMs) have been critically discussed in this work. It was found that PIL/IL composite membranes and MMMs may have a better opportunity for industrial CO 2 separations if gas permeability can be further improved. In the end, the perspective for the development of more efficient membranes based on the understanding of the structure–property relationship of PILs with separation performance was also proposed. Moreover, the separation performance of PIL-based membranes should be further evaluated in terms of techno-economic feasibility and environmental impact analysis.