Porous Polylactic Acid Membranes by NIPS : Solvent Effect on Membrane Characteristics

Polymeric membranes are widely used for molecular separations in industry, but growing environmental concerns are driving the search for sustainable alternatives to synthetic polymers. This work fabricates porous asymmetric polylactic acid (PLA) membranes using the nonsolvent‐induced phase separation (NIPS) method and evaluates the effects of three solvents (DMSO, DMAc, and DMF) and three porogenic additivies (PVP, PEG400, and PEG35000). The membranes were characterized in terms of morphology, hydrophobicity, swelling degree, and Brunauer–Emmett–Teller analysis. Results demonstrated that solvent selection influences membrane morphology, particularly the pore size distribution. The PLA/PVP/DMAc and PLA/PVP/DMF membranes exhibited high porosities (72.3% ± 0.21% and 67.69% ± 0.63%, respectively), with distinct swelling degrees and contact angle wettability. DMAc was identified as the most suitable solvent for membrane formation and was therefore selected for further studies on porogenic additives. The addition of PEG400 to the PLA/PEG400/DMAc membrane promotes hydrophobicity on bottom layer of the membrane, significantly reducing the swelling degree, differed to PLA/PVP/DMAc and PLA/PEG35000/DMAc. These achievements provide novel insights into the impact of solvent and pore‐forming agents on PLA membrane properties, offering guidance for the development of future sustainable filtration technologies.