Preparation, characterization and gas permeation study of PSf/MgO nanocomposite membrane

Nanocomposite membranes composed of polymer and inorganic nanoparticles are a novel method to enhance gas separation performance. In this study, membranes were fabricated from polysulfone (PSf) containing magnesium oxide (MgO) nanoparticles and gas permeation properties of the resulting membranes were investigated. Membranes were prepared by solution blending and phase inversion methods. Morphology of the membranes, void formations, MgO distribution and aggregates were observed by SEM analysis. Furthermore, thermal stability, residual solvent in the membrane film and structural ruination of membranes were analyzed by thermal gravimetric analysis (TGA). The effects of MgO nanoparticles on the glass transition temperature (Tg) of the prepared nanocomposites were studied by differential scanning calorimetry (DSC). The Tg of nanocomposite membranes increased with MgO loading. Fourier transform infrared (FTIR) spectra of nanocomposite membranes were analyzed to identify the variations of the bonds. The results obtained from gas permeation experiments with a constant pressure setup showed that adding MgO nanoparticles to the polymeric membrane structure increased the permeability of the membranes. At 30 wt% MgO loading, the CO2 permeability was enhanced from 25.75×10-16 to 47.12×10-16 mol.m/(m².s.Pa) and the CO2/CH4 selectivity decreased from 30.84 to 25.65 when compared with pure PSf. For H2, the permeability was enhanced from 44.05×10-16 to 67.3×10-16 mol.m/(m².s.Pa), whereas the H2/N2 selectivity decreased from 47.11 to 33.58.