Our group synthesized defect-free of ZIF-8/P84 mixed matrix membranes with good interphase compatibility. Membranes displayed remarkably improved CO2/CH4 separation performances, indicative of a synergetic effect of the selective adsorption and molecular sieving property arising from ZIF-8 nanoparticle fillers. This work has been published in Journal of Membrane Science, 2018, 562, 76-84.