Self-Cleaning Superhydrophilic Membranes via Eco-Friendly Modification for High Flux Oil-water Separation

Superhydrophilic membranes hold significant promise for oil/water separation in effluent treatment due to their exceptional separation efficiency and inherent anti-oil properties. However, persistent challenges such as irreversible membrane fouling and complex cleaning procedures caused by oil ingress during operation remain unresolved. While extensive research has explored diverse substrates, such as stainless steel mesh, polysulfone ultrafiltration membranes, and copper mesh, conventional fabrication methods often rely on environmentally hazardous processes, such as chemical etching or intricate substrate engineering, to achieve robust adhesion between substrates and superhydrophilic coatings. Furthermore, existing strategies for emulsified oil separation frequently compromise flux efficiency. To address these limitations, this study introduces a laser-assisted morphogenetic fabrication technique to create an antifouling, scale-like substrate. A biodegradable, nontoxic chitosan modification layer is integrated via binding sites, enhancing interfacial adhesion while optimizing mechanical stability and coating porosity. The resultant membrane exhibits self-cleaning functionality alongside superhydrophilicity, achieving a sustained flux of 59 683.103 L m^{- 2} h^-1 and maintaining >99.996% separation efficiency over 100 cycles. The mild, eco-friendly synthesis process and the membrane's superior performance underscore its potential for scalable application in sustainable oil/water separation. This work advances the rational design of durable superhydrophilic coatings and offers a viable pathway for developing high-flux, antifouling separation technologies.