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

Development of high-performance mixed matrix membranes (MMMs) is of great significance for CO 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 CO/N 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 CO permeability monotonously increases in spite of the CO/N selectivity first increasing and then decreasing with the MMT content elevating from 0% to 10% in MMMs. The highest CO/N selectivity could reach to 120.3, along with the CO permeability of 130.6 Barrer for the MMMs made by MMT content of 6%.