Gas Transport Properties of the Metal–Organic Framework (MOF)-Assisted Polymer of Intrinsic Microporosity (PIM-1) Thin-Film Composite Membranes

The current study summarizes the findings of single-gas transport performances of mixed matrix thin-film composite membranes consisting of metal–organic frameworks (MOFs) incorporated into a polymer of intrinsic microporosity (PIM-1). Mg-MOF-74, MIL-53, TIFSIX-3, and Zn2(bim)4 were investigated as stand-alone materials and as incorporated into the PIM-1 polymer matrix serving as a selective layer of thin-film composite membranes by various methods: Fourier-transform infrared spectroscopy, solid-state NMR, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The effect of MOF loading and nature on the mixed-matrix membrane morphology and operation were analyzed by varying the MOF content in the polymer matrix from 2 to 10 wt % with respect to the dry polymer weight. The results show that the incorporation of MOFs into the PIM-1 polymer matrix boosts the permeance and selectivity of H2 and O2 over N2, and the prepared PIM-1/TIFSIX_4 mixed matrix membrane shows better separation performance for CO2/CH4 than pure PIM-1. Such membranes can be good candidates for ammonia purge gas, oxygen enrichment, and acid gas treatment applications.