Preparation of Ni-MOF-74/SBS mixed matrix membranes and its application of CH 4 /N 2 separation

Abstract A series of mixed matrix membranes (MMMs) were fabricated with Ni-MOF-74 as filler and poly (styrene-b-butadiene-b-styrene) (SBS) polymer as matrix materials for CH 4 /N 2 separation. MMMs were characterized by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Gas separation behavior was investigated by measuring single and mixed gases. For the single gas, the CH 4 permeability of the MMMs incorporated with 15 wt% Ni-MOF-74 (Ni-MOF-74/SBS-15) reached 83.5 Barrer, which was 116% higher than that of SBS (38.6 Barrer), while its ideal selectivity remained the same. CH 4 permeability can further increase to 176.6 Barrer with the increase in temperature to 55 °C. For the CH 4 /N 2 (50/50 vol%) mixed gas, the Ni-MOF-74/SBS-15 sample exhibited increasing CH 4 permeability (74.7 vs 36.7 Barrer), while selectivity remained unchanged relative to that of the pure SBS membrane.