Modification of gas selective SAPO zeolites using imidazolium ionic liquid to develop polysulfone mixed matrix membrane for CO2 gas separation

Ionic liquids (ILs) with high CO2 solubility and selectivity have been extensively studied in recent years to improve the performance of CO2 separation membranes. The progress in the development of supported IL membranes, polymerized IL membrane, polymer/IL gel membranes and membrane gas absorption using IL is limited by the high viscosity and price of ILs. In this work, the gas selective SAPO-34 zeolite was modified using lemiml[TF2NI IL before the zeolites were incorporated into polysulfone (PSf) asymmetric membrane which was prepared by phase inversion. The main objective of this work is to study the effects of immersion duration on the IL-functionality of zeolite, membrane morphology and gas separation properties of PSf/SAPO-34 zeolite mixed matrix membrane. The incorporation of IL into the SAPO zeolite was confirmed by energy dispersive X-ray analysis. This analysis also proved the well dispersion of SAPO-34 particles with IL modification for 6 h due to the improved polymer/filler interface morphology as shown by scanning electron microscopy analysis. The gas separation test further revealed that the membrane containing SAPO-34 modified with IL for 6 h showed a great enhancement in both CO2/CH4 and CO2/N-2 selectivity (approximately 486% and 232% respectively) over the unmodified mixed matrix membrane. (C) 2016 Published by Elsevier Inc.