Poly(2,6-dimethyl-1,4-phenylene oxide)/zeolitic imidazolite framework-8 mixed matrix membranes for olefin/paraffin separations

In this study, poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)/zeolitic imidazolate framework-8 (ZIF-8) mixed matrix membranes (MMMs) were prepared and studied for propylene/propane separation. ZIF-8 nanoparticles were synthesized in an organic medium. Characterization of synthesized ZIF-8s showed that these nanoparticles were pure ZIF-8 material with mean particle size of ca. 60 nm. The MMMs were characterized by energy-dispersive X-ray spectroscopy (EDX), and gas permeation. EDX results showed very good dispersion and adhesion between PPO polymer and ZIF-8 nanoparticles. Gas permeation results showed that permeability of propylene and selectivity of propylene over propane significantly increased in the MMMs by increasing the amount of ZIF-8 loading in the membranes. At ZIF-8 loading of 35 wt%, the propylene permeability and propylene/propane ideal selectivity were enhanced 240% and 40% respectively compared to those of neat PPO polymer