In this study, crystalline UiO-66 and NH2-UiO-66 metal organic frameworks (MOFs) were prepared by typical solvothermal method and then were transformed into amorphous phase by using ball milling process. The prepared MOFs were incorporated into tertiary polymer blend matrix including polyethersulfone/ polysulfone/polyvinylpyrrollidone (PES/PSF/PVP:40/40/20 wt%) to examine gas separation performance of constructed mixed matrix membranes (MMMs). The synthesized MMMs were analyzed by FT-IR, SEM, TGA, XRD, AFM, and DSC methods and also by pure gas permeation test for CO2 and CH4 gases. Afterwards, the surface of amorphous MOF-contained MMMs was influenced by O2 plasma to thrive polar groups of membranes surface. The best gas separation result owned to amorphous NH2-UiO-66 comprised MMM treated by O2 plasma for 3 min at 600 W with CO2 permeability and CO2/CH4 selectivity of 10.96 Barrer and 97.91, respectively. The mentioned MMM showed CO2 permeability and CO2/CH4 selectivity of 8.69 Barrer and 75.56 before plasma treatment which were 170 and 50% higher than those of pristine PES/PSF/PVP blend membrane.
