Mixed matrix membranes with intrinsic microporous/UiO-66 post-synthesis modifications with no defects for efficient CO2/N2 separation

Mixed matrix membranes (MMMs) based on metal–organic frameworks (MOFs) are expected to realize efficient separation of CO 2 . However, interfacial compatibility issues between MOFs and polymer matrices limit their performance. In this work, a post-synthesis modification (PSM) strategy was adopted to convert UiO-66 into porous liquids (PLs). MMMs were prepared by incorporating PLs into PIM-1 matrix. The PLs have a liquid-like behavior and can be evenly scattered in PIM-1 matrix to form an interface without defect. The SEM morphology analysis further certified that MMMs had no interface defect and PLs had brilliant compatibility with the polymer film . In addition, the CO 2 -philic ether bonds of the EO fragments enable the MMMs to have superior CO 2 selective separation. Compared with pure PIM-1, the highest CO 2 permeability was improved by 158.0 % and 62.5 % was the increase in CO 2 /N 2 selectivity, arriving at 7211.7 Barrer and 26.0, respectively. Meanwhile, the overall separation performance of MMMs for CO 2 /N 2 exceeds the 2008 Robson upper limit, showing outstanding gas separation performance.