Building high-speed facilitated transport channels in Pebax membranes with montmorillonite for efficient CO2/N2 separation.

Abstract

Development of high-performance mixed matrix membranes (MMMs) is of great significance for CO₂ separation membrane technology, in order to improve the commercial competitiveness and practical applications. Montmorillonite (MMT) was developed as a dopant to fabricate Polyether block amide (Pebax1074)-based MMMs for strengthening the CO₂/N₂ separation. The morphology, chemical groups, microstructure, and thermal properties of MMMs were characterised by scanning electron microscope, FTIR spectroscopy, X-ray diffraction and thermal analysis, respectively. The effects of MMT contents, permeation pressure and permeation temperature on the gas separation performance of the Pebax/MMT MMMs were investigated. The results show that the uniformly dispersed dopants MMT in the membrane matrix significantly influence the thermal stability and the structural compactness of MMMs. Moreover, the CO₂ permeability monotonously increases in spite of the CO₂/N₂ selectivity first increasing and then decreasing with the MMT content elevating from 0% to 10% in MMMs. The highest CO₂/N₂ selectivity could reach to 120.3, along with the CO₂ permeability of 130.6 Barrer for the MMMs made by MMT content of 6%.