Influence of Different Solvents on the Development of a Greener Approach for the Fabrication of Polysulfone/Polydimethylsiloxane Hollow Fiber Membrane for Air Separation

Membrane technology is widely adopted in industry due to its scalability, compact footprint, and low energy consumption. However, conventional fabrication via nonsolvent-induced phase separation (NIPS) generates hazardous solvent-laden wastewater, necessitating greener alternatives. This study introduces an environmentally benign approach for polysulfone (PSF) hollow fiber air separation membranes, incorporating dimethyl sulfoxide (DMSO)—a less toxic solvent—to minimize conventional solvents. DMSO's high viscosity also lowers the usage of PSF by enabling room-temperature dissolution. Hollow fiber supports were coated with polydimethylsiloxane (PDMS) solutions (3%–15% concentrations) over 1–3 cycles to optimize defect sealing. Optimal performance yielded an O₂/N₂ selectivity of 4.70 and O₂ permeance of 8.49 GPU using 3 cycles of cross-linked 3% PDMS. This DMSO-DMF methodology advances greener membrane production, minimizing environmental impact while maintaining efficacy.