Comparison of ZnO nanofillers of different shapes on physical, thermal and gas transport properties of PEBA membrane: experimental testing and molecular simulation

Abstract

AbstractBACKGROUNDPEBA and nano‐ZnO have been discussed for membrane modification and for gas separation in different studies and in mixed matrix membranes (i.e. PEBA/TiO2, PE/ZnO); however, no report has been published on the gas transport properties of ZnO/PEBA hybrid membranes.RESULTSMolecular simulation and experimental approaches were done using PEBA 1657 mixed matrix membranes (MMMs) loaded with ZnO nanorod‐ and nanosphere shaped nanomaterials at 0.5 wt% and 1 wt% loading to investigate the gas separation properties of these MMMs. Structural characterizationwas carried out by FESEM, AFM, BET and FTIR on synthesized membranes, and FFV and WAXD on the simulated membrane cells to study their structural properties. Thermal analysis was carried out by TGA, DMTA and calculation of the glass transition temperature to investigate the thermal properties of the MMMs. The results showed that the addition of ZnO filler significantly improved both the physical and thermal properties of the MMMs based on the characterization tests. The transport properties of the MMMs for three single light gas molecules (CO2, CH4 and N2) were investigated using experimental set‐up testing (permeability and selectivity), and also by molecular dynamic and Monte Carlo approaches in molecular simulation (diffusivity and solubility). The addition of ZnO nanomaterials in both shapes to the polymeric membrane significantly increased the transport properties; for example, CO2 permeability increased from 120 for membrane without nanomaterial to 135 barrer for membrane with 0.5 wt% of nanosphere ZnO and 157 barrer for membrane with 0.5 wt% nanorod ZnO.CONCLUSIONThe permeability of CH4 and N2 gases into all samples showed no significant change with an increase in pressure or ZnO loading which is likely due to the penetration paths in the membranes. The membrane with 1 wt% ZnO nanorods had the best performance in the Robeson upper bound 2008 diagram. This sample is thus suggested for industrial development. The simulation results showed a similar trend for the membranes and gas molecules, with an error of 25% to 65% from experimental results. We conclude that the PEBA/1 wt% ZnO nanorods membrane could be an ideal solid polymer membrane for gas separation applications. © 2018 Society of Chemical Industry