Mixed matrix membranes containing oriented two-dimensional ZIF-L nanosheets for efficient H2/CO2 separation

ZIF-L material was incorporated into the polyimide (PI) matrix to prepare MMM for H2/CO2 gas separation. Compared with casting and flat scraping methods, the membrane prepared by spin coating method provides higher selectivity and excellent permeability under the same high MOF loading. The excellent separation performance is due to the ordered arrangement of ZIF-L in the matrix, which forms an orientation film that provides a fast transport channel for H2 molecules and effectively interferes with the diffusion of CO2 molecules with strong interactions between ZIF-L. Meanwhile, in-plane orientation is beneficial for optimizing the compatibility between nanosheets and polymer interfaces, thereby maximizing membrane separation performance.