Synergistic effect of adding graphene oxide and ZIF-301 to polysulfone to develop high performance mixed matrix membranes for selective carbon dioxide separation from post combustion flue gas

Graphene oxide (GO) nanosheets and zeolitic imidazole frameworks (ZIF-301) were synergistically integrated to glassy polysulfone (PSF) to prepare mixed-matrix membranes (MMMs) for CO₂ separation from post combustion flue gas. Both nanofillers were incorporated in PSF in varying compositions using solution-casting technique to optimize CO₂ separation performance of composite membranes form dry and wet gases. The flexible MMMs rendered homogeneous dispersion of nanofillers, improved polymer-filler adhesion, and thermally stable structure. Gas sorption analyses along with dry and wet gas permeation experiments showed improved CO₂ permeability and CO₂/N₂ selectivity of MMMs due to synergistic effect of nanofillers. The prepared MMMs demonstrated about four- and three-folds increment in CO₂ permeability CO₂/N₂ selectivity respectively as compared to that of bare PSF membrane. Separation performance of composite membranes was found to better than already existing membranes; they were stable in presence of water and performance was not affected by humid conditions.