Preparation of ultrathin and highly loaded MOF mixed matrix membranes with honeycomb-like structure via ordered array self-assembly

Metal-organic frameworks mixed matrix membranes (MOF MMMs) have many advantages such as structural diversity and easily large-scale preparation, but current MOF MMMs are difficult to meet the economic and technical requirements of membrane industrial applications, mainly because of the limitation of MOF loadings. Here, a type of polymer-templated MOFs (PMOFs) have been prepared, and then used to prepare the honeycomb-like mixed matrix membrane with highest MOF loading of 93.5 % by using polymer-induced ordered array self-assembly. Polymer-templating endowed MOFs with excellent self-assembly ability due to the rich functional groups of grafted polymer fragments, promoting the formation of honeycomb arrangement structure. The gas sorption, material characterizations and separation performance revealed that the PMOFs provided the resulting honeycomb-like MMMs with favorable CH4 sorption and ultrafast diffusion pathways by forming unimpeded transfer channels. Herein, the prepared honeycomb-like PCuBTC membranes with thickness of about 46.1 nm exhibited exceptionally high pure CH4 permeance of 1025 GPU and moderated ideal CH4/N2 selectivity of 6.57.