Facile papermaking fabrication of a PPS/PAN nonwoven composite membrane for efficient oil-in-water emulsion separation

With the increasing challenges of industrial wastewater and oil spills, efficient oil-in-water emulsion separation has become crucial for environmental remediation. However, existing membranes often fail to deliver high flux, low energy consumption, and effective separation. This study introduces a scalable route wet papermaking coupled with a single-step TA/Fe 3+ metal-phenolic coating to fabricate a superhydrophilic TA/Fe 3+ @PPS/PAN membrane. The resulting membrane features a well-defined three-dimensional fibrous network that imparts high water permeability and robust structural integrity. The membrane exhibits a water contact angle of 0° and an underwater oil contact angle of 160°, indicating outstanding superhydrophilicity and underwater superoleophobicity. These surface characteristics contribute to its outstanding antifouling performance. Under surfactant-stabilized O/W emulsion testing, the membrane achieved >98 % oil rejection across all oils (up to 99.15 % for dodecane) with consistently high pure-water fluxes of 1396–1603 L/m 2 h. Comprehensive evaluations demonstrated notable improvements in hydrophilicity, separation efficiency, fouling resistance, and operational stability under harsh conditions. Additionally, the membrane maintained consistent performance over 10 filtration cycles with minimal flux decline. Owing to these attributes, the TA/Fe 3+ @PPS/PAN membrane exhibits significant potential for practical oil-in-water emulsion separation, particularly under chemically harsh conditions.