Pim-1 Based Mixed Matrix Membranes for Superior Co2/N2 Separation by Tuning Co2-Philic Mxene Nanosheets

Abstract

Membrane gas separation technologies show great potential in CO2 separation. In this work, a series of novel mixed matrix membranes (MMMs) of two-dimensional MXene nanosheets incorporated polymers of intrinsic microporosity (PIMs) were developed for CO2/N2 separation. The emdedded MXene (Ti3C2TX) nanosheets with numerous polar groups increase the affinity between the prepared MMMs and CO2 molecules, which enhanced CO2/N2 selectivity and CO2 permeability significantly. Besides, the uniformly dispersed MXene nanosheets inside the PIM-1 matrix provide fast transport channels for CO2 passing through intra- and inter-flake pores, and thus significantly enhanced the CO2 diffusion coefficient. The prepared MMM with an MXene loading of 0.5 wt% exhibits the oprimised separation performance with a superior CO2 permeability of 12475.3 Barrer and 32.7 of CO2/N2 selectivity. It was also found that the gas separation performances of all the prepared PIM-1/MXene membranes exceed the 2019 Robeson upper bound for the CO2/N2 pair, which indicates the great potential for their industrial CO2 separation or capture.

Keywords: Mixed matrix membranes, PIM-1, MXene, CO2/N2 separation, CO2 permeability