The One‐Step Preparation of Mussel‐Inspired PDA / SBMA Composite Membranes for Efficient Oil–Water Emulsion Separation

Faced with the large amount of oily wastewater with complex compositions generated from petrochemical, food, and other industries, traditional separation technologies often struggle to simultaneously achieve high efficiency and economic feasibility. Therefore, the development of novel separation materials and methods is urgently required. In this study, inspired by mussel chemistry, a commercial PVDF membrane was modified to achieve superhydrophilicity via a one‐step co‐deposition strategy. Dopamine was used to initiate the polymerization of the SBMA monomer and form covalent bonding, while its excellent adhesive property enabled the construction of a stable PDA/SBMA synergistic interfacial layer. After the introduction of abundant zwitterionic groups onto the membrane surface, a stable hydration layer was formed, endowing the membrane with pronounced superhydrophilicity and creating an oil‐repelling interface underwater, thereby imparting excellent underwater superoleophobicity. Various characterization techniques were employed to systematically investigate the morphology, elemental composition, wettability, and antifouling properties of the membranes before and after modification. By optimizing the SBMA content, the prepared superhydrophilic membrane exhibited a minimum water contact angle of 26°, and the pure water flux increased by 22.6 times compared with the pristine membrane. The membrane also demonstrated high permeation flux for various oil‐in‐water emulsions (exceeding 2200 L m −2 h −1 at 0.05 MPa) and high separation efficiency (up to 99.5% under gravity‐driven conditions). In addition, the membrane showed excellent chemical stability in strong acidic and alkaline environments, as well as good salt resistance and corrosion resistance. This study provides a theoretical basis for enhancing membrane separation performance through the synergistic modification of polydopamine and zwitterionic polymers.