Self-Supporting Thin-Film Nanofibrous Ultrafiltration Membranes: Enhancing Functionality and Affordability

Abstract

Ultrafiltration (UF) membranes are essential in water treatment, providing efficient removal of contaminants. Commercial UF membranes are typically produced using phase inversion, but their dense structure and tortuous pore channels limit water flux. This study develops a new thin film composite (TFC) UF membrane with high permeability, based on a nanofibrous support and a thin top layer. We first fabricated a polyethylene terephthalate (PET) electrospun nanofibrous sublayer from recycled PET flakes, then added a second, thinner nanofibrous layer on top. Finally, a hydrophilic chitosan (Cs)/multiwalled carbon nanotube (MWCNT) layer was applied. The fabricated membranes demonstrated outstanding performance, with a permeability of 240 L/m2 h bar, indicating a substantial increase in water flux compared to conventional UF membranes. The oil/water emulsion flux reached 60 L/m2 h bar, showcasing the membrane's high capacity for rapid filtration while maintaining effective separation. Notably, the membranes achieved an oil emulsion retention rate of approximately 99.9%, highlighting their excellent ability to remove emulsified oils and contaminants from water. When compared to existing nanofibrous and other types of membranes, our membrane displayed superior flux and retention capabilities, suggesting enhanced efficiency and potential for energy savings in practical applications. © 2025 Wiley Periodicals LLC.