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

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% gamma-alumina nanoparticles into the PSF matrix resulted in about the respective 43% and 41% increase in CO2 and O-2 permeability together with a rise in CO2/CH4 and O-2/N-2 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.

Automated summary

A series of PSF membranes were prepared using different solvents, and the influence of propionic acid on gas separation properties was explored. Incorporating propionic acid and gamma-alumina nanoparticles into the PSF matrix can significantly improve gas separation performance.