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.