Preparation of mixed matrix membrane with high efficiency SO2 separation performance by photosensitive modification and enhanced adsorption of metal-organic framework

In this study, functionalized MOF (Azo@MOF-199) is prepared by introducing azo molecules into the pores of MOF-199 by vacuum assisted method, and the effects of the molecular structure of MOF material and its affinity with the modified material on the SO2 permeability and SO2/N-2 selectivity of the prepared mixed matrix membrane are explored. The MOF-199 with higher porosity and specific surface area introduced in Pebax matrix has constructed rich SO2 transport channel, the -NH2 as SO2-facilitated groups and open metal sites in functionalized MOF increase the affinity to SO2. The SO2 adsorption capacity of Azo@MOF-199 reached 580 mg/g at 0 degrees C/Vis. The SO2 permeability and SO2/N-2 selectivity of the prepared mixed matrix membrane are significantly improved, which are 3204.2 Barrer and 930, respectively. The prepared membrane has a long-term stability of more than 120 h. In particular, under different light conditions (UV and Vis), Pebax/Azo@MOF-199 membrane is used to investigate the SO2 separation process with light response, and the change of membrane properties caused by the change of light conditions is reversible. [GRAPHICAL ABSTRACT]