Rational design of MOFs-based three-component mixed matrix membranes for efficient propylene/propane separation and physical aging mitigation

Membrane materials with high gas permeation and satisfied selectivity are crucial for achieving efficient C 3 H 6 /C 3 H 8 separation. Although PIM-1 membranes have drawn tremendous attention in gas separation, their broader application is hampered by intrinsic aging phenomenon and relatively low C 3 H 6 /C 3 H 8 selectivity. In this work, the Ni(AIP)(BPY) 0.5 (defined as Ni-MOF) with thermodynamic and kinetic synergistic separation effect on C 3 H 6 /C 3 H 8 was introduced to PIM-1/Matrimid 5218 blend matrix for preparing mixed matrix membranes (MMMs) to overcome the drawbacks of PIM-1. Benefiting from the rapid C 3 H 6 transport channel of Ni-MOF, the PIM-Matrimid/Ni-MOF-7 MMMs exhibit exceptional separation properties, achieving C 3 H 6 permeability of 1762.5 Barrer and C 3 H 6 /C 3 H 8 selectivity of 8.5 (increased by 107% over PIM-1 membranes). Moreover, the C 3 H 6 permeability of PIM-Matrimid/Ni-MOF-7 MMMs showed only a 14% decline after 60 days. This work not only offers a new perspective for developing next-generation C 3 H 6 /C 3 H 8 separation membranes but also emphasizes the importance of rational design in maximizing the mixed-matrix effect.