The effect of silica nanoparticles on polysulfone–polyethylene glycol (PSF/PEG) composite membrane on gas separation and rheological properties of nanocomposites

Currently, composite membranes play a significant role in the separation of acidic gases. Inorganic nanoparticles are used in these composite membranes to enhance the thermal and chemical properties of composites. In this study, polysulfone–polyethylene glycol/silica (PSF–PEG/silica) nanocomposite membranes were investigated for the purpose of improvement of the N₂, O₂, CH₄ and CO₂ separation properties. The results of gas permeability in nanocomposite membranes showed that the PSF/PEG 10,000 membrane, with 20 wt% of silica, provided the best gas separation properties. CO₂ permeability in the nanocomposite membrane with 20 wt% of silica was 13.36 Barrer. In addition, the ideal selectivity for CO₂/N₂ paired gases in this membrane was 45.76, which was higher than the values obtained in the pure PSF membrane and the composite membrane with 20 wt% PEG 10,000. In addition, scanning electron microscopy, infrared spectroscopy, thermal gravimetric analysis, X-ray diffraction, differential scanning calorimetry and a tensile strength test were all used to examine the membrane structure and morphology of the nanocomposite. Finally, mechanical rheometry was used to study the rheological properties of hybrid nanosized composites and the effect of nanoparticle percentage on them.