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 C[O.sub.2] and [O.sub.2] permeability together with a rise in C[O.sub.2]/ C[H.sub.4] and [O.sub.2]/[N.sub.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. KEYWORDS gas separation, Lewis acid-base complex, mixed matrix membranes, polysulfone membranes, solvent effect
1 | INTRODUCTION Global warming due to C[O.sub.2] emission into the atmosphere, and production of clean and conventional energies ([H.sub.2] and C[H.sub.4], respectively) has attracted great attention to the need [...]