Preparation of amino-modified ZIF-8 and polyimide mixed matrix membranes
In this paper,the polyimide mixed matrix membrane was prepared by mixing the homemade aminated ZIF-8-NH2 particles with co-polyimide[PI,6FDA-DAM/DABA(3∶2)]using a drop-coating method.The effects of ZIF-8-NH2 doping content on the structure and properties of MOF/PI mixed matrix membranes were investigated by studying the results of microstructure,infrared,and gas separation performance properties of the mixed matrix membranes.The results showed that the homemade ZIF-8-NH2 material had a particle size of about 70 nm and was mixed with polyimide(PI)uniformly.When the mass concentration of ZIF-8-NH2 reached 15%,the mixed matrix membrane had the best performance in separation,with a CO2 permeation coefficient of 206.91 Barrer,and its selectivity reached 66.39 while maintaining a high gas permeation flux,and the separation performance to CO2/CH4 system exceeded the Robeson 2008 upper limit.