Preparation of high performance mixed matrix membranes by one-pot synthesis of ZIF-8 nanoparticles into Pebax-2533 for CO2 separation

Herein, an interesting strategy, viz. one-pot synthesis, is proposed to incorporate ZIF-8 nanoparticles into the Pebax-2533 for facile fabrication of MMMs with high permeability and selectivity. Based on characterization analyses, incorporating 8 wt% of ZIF-8 particles via this route increased the fractional free volume (FFV) of the membranes, which contributed to the improvement in the CO 2 permeability, avoided the aggregation of the nanoparticles in the polymer matrix, increased the CO 2 sorption property due to imidazole linkers, boosted the screening properties owing to intrinsic pore size, thereby improved CO 2 /CH 4 and CO 2 /N 2 selectivities, and in addition, resulted in membranes with desirable thermal properties. As a result, MMM with 8 wt% of ZIF-8 by providing an admirable performance, improved the CO 2 permeability and CO 2 /CH 4 and CO 2 /N 2 selectivities of the neat Pebax-2533 membrane from 62.20 Barrer, 11.35, and 24.98 to 158.43 Barrer (+155% enhancement), 27.73 (+144.32%) and 50.76 (+103.21%), respectively. This membrane at an operating pressure of 8 bar overcame Robeson’s upper bound (1991) in the case of CO 2 /CH 4 separation. • Pebax-2533 MMMs containing ZIF-8 nanoparticles were prepared by one-pot synthesis method. • Appropriate polymer/filler interfacial compatibility was achieved by suitable dispersion of ZIF-8 within polymer matrix. • One-pot synthesized MMMs had higher gas-pair selectivities than the conventional MMMs containing ZIF-8. • MMM containing 8 wt% of ZIF-8 showed the highest CO 2 /CH 4 and CO 2 /N 2 selectivities with appropriate CO 2 permeability.