SIFSIX-3-Zn/PIM-1 mixed matrix membranes with enhanced permeability for propylene/propane separation

Mixed matrix membranes (MMMs) have showed improved propylene/propane selectivity compared to the pristine polymer membrane, but the industrial-scale propylene purification projects based on membrane separation technology are still restrained by its low permeability. In this work, a new fluorinated MOF-based mixed matrix membrane is developed by incorporating the SIFSIX-3-Zn (or Zn(pyrz)2(SiF6)) nanoparticles into the polymer of intrinsic microporosity (PIM-1) matrix. The robust SIFSIX-3-Zn with high surface area and suitable aperture size can create new delivery channels to facilitate transport of propylene. 10 wt% SIFSIX-3-Zn/PIM-1 MMMs shows an optimal enhancement of C3H6 permeability from 1701.9 Barrer to 4012.1 Barrer with the ideal C3H6/C3H8 selectivity simultaneously increasing by nearly 120%. This performance is placed in unpopulated high permeability area of the trade-off plot and surpasses the upper bound. This novel fluorinated MOF-based mixed matrix membrane may have great potential for industrial C3H6/C3H8 separation. [Display omitted] •Fluorinated MOF/PIMs mixed matrix membrane was fabricated for C3H6/C3H8 separation.•The mixed matrix membranes showed good propylene permeability exceeding 4000 Barrer.•This work could potentially provide a strategy to overcome low C3H6 permeability.