Sodium alginate-induced interfacial assembly for constructing superhydrophilic polymer membranes with enhanced antifouling and photo-Fenton self-cleaning performance

Membrane fouling remains a major obstacle limiting the practical application of polymer membranes in separation processes. Herein, a sodium alginate-induced stepwise interfacial assembly strategy was developed under mild aqueous conditions to impart the membrane surface with superhydrophilicity and photo-Fenton self-cleaning capability. Unlike conventional hydrothermal or vacuum-assisted self-assembly routes, this approach enables in-situ Prussian Blue (PB) growth on the alginate-functionalized surface, producing a uniform and robust functional interface. The resulting membranes exhibited superhydrophilicity in air and under-water superoleophobicity, with under-water oil contact angles above 150.3°. Under a transmembrane pressure of 0.1 MPa, the optimized membrane exhibited a high permeate flux of 3311.3 L m⁻² h⁻¹ bar⁻¹ and an oil rejection efficiency of 98.6 % during the separation of petroleum ether-in-water emulsions. Benefiting from the interfacial photo-Fenton activity of PB, the membranes effectively removed organic contaminants and restored 91.7 % of their initial flux after self-cleaning. This work demonstrates a mild and controllable interfacial assembly strategy for constructing photo-Fenton-active surfaces with integrated antifouling and self-cleaning functionalities.