Influence of solvent, Lewis acid–base complex, and nanoparticles on the morphology and gas separation properties of polysulfone membranes

Abstract

A series of polysulfone (PSF) membranes were prepared using different solvents: dimethylformamide (DMF), tetrahydrofuran, dimethylacetamide, and n‐methyl‐2‐pyrrolidone (NMP). The PSF membrane prepared by NMP showed the highest gas permeability. The influence of propionic acid as a Lewis acid on gas separation properties of the PSF was explored. The PSF membrane prepared by the casting solution containing 25 wt% PSF, 35 wt% propionic acid, and 40 wt% NMP showed a superior gas separation performance. The gas permeation measurements indicated that incorporating 30 wt% γ‐alumina nanoparticles into the PSF matrix resulted in about the respective 43% and 41% increase in CO2 and O2 permeability together with a rise in CO2/CH4 and O2/N2 selectivities (13% and 7%, respectively). Furthermore, by rearranged modified Maxwell model, the role and nature of the interfacial layer in the PSF‐based mixed matrix membranes were mathematically analyzed considering a reduced permeability factor.

Statistical analysis of CO2/N2 gas separation permeance and selectivity using taguchi method

“…Increasing the polymer content in the casting solution yields more desirable but less efficient asymmetric gas separation membranes [ 56 ]. Conversely, casting asymmetric membranes from low-polymer solution results in higher gas separation permeance but reduces selectivity [ 31 , 58 ]. As an illustration, when the polymer concentration is 20 wt%, the membrane exhibits longer macrovoids.…”