Particle‑level dopamine pre‑modification combined with NIPS fabrication for oil‑water separation membranes with superhydrophilicity, regenerability, and localized repairability

Conventional polymer membranes are widely employed in oily wastewater treatment owing to their high porosity and permeability. However, they always suffer from irreversible fouling during operation, resulting in performance degradation and eventually disposal, which raises significant environmental and economic concerns. Here, we present a strategy for fabricating recyclable and repairable superhydrophilic membranes. Polymer powders (PVDF, PES, PAN) were first modified with dopamine, and then fabricated into membranes via the non‑solvent induced phase separation method. The resulting membrane exhibited superhydrophilicity and underwater superoleophobicity, achieving over 98.7% separation efficiency for various oil-in-water emulsions, along with excellent antifouling properties, pH stability, chemical durability, mechanical strength, and salt tolerance. Notably, for localized damage, simple and efficient in situ repair methods can be utilized to repair the damaged area with substantial performance recovery. While severely damaged membranes can achieve effective regeneration by dissolution in organic solvent followed by recasting. This work offers a sustainable approach for membrane recycling and repair, addressing key challenges such as non-recyclability and performance deterioration in membrane technology.