Smart membranes with responsive wettability show promise for controllably separating oil/water mixtures, including immiscible oil-water mixtures and surfactant-stabilized oil/water emulsions. However, the membranes are challenged by unsatisfactory external stimuli, inadequate wettability responsiveness, difficulty in scalability and poor self-cleaning performance. Here, we develop a capillary force-driven confinement self-assembling strategy to construct a scalable and stable CO₂-responsive membrane for the smart separation of various oil/water systems. In this process, the CO₂-responsive copolymer can homogeneously adhere to the membrane surface by manipulating the capillary force, generating a membrane with a large area up to 3600 cm² and excellent switching wettability between high hydrophobicity/underwater superoleophilicity and superhydrophilicity/underwater superoleophobicity under CO₂/N₂ stimulation. The membrane can be applied to various oil/water systems, including immiscible mixtures, surfactant-stabilized emulsions, multiphase emulsions and pollutant-containing emulsions, demonstrating high separation efficiency (>99.9%), recyclability, and self-cleaning performance. Due to robust separation properties coupled with the excellent scalability, the membrane shows great implications for smart liquid separation.

具有响应润湿性的智能膜有望实现可控分离油/水混合物，包括不混溶的油水混合物和表面活性剂稳定的油/水乳液。然而，这些膜面临着外部刺激不理想、润湿响应能力不足、可扩展性困难和自清洁性能差等挑战。在这里，我们开发了一种毛细管力驱动的限制自组装策略，以构建可扩展且稳定的CO ₂响应膜，用于各种油/水系统的智能分离。在此过程中，CO ₂响应性共聚物可以通过操纵毛细管力均匀地粘附在膜表面，生成面积高达3600 cm ²的大面积膜，并在高疏水性/水下超亲油性和超亲水性/水下超疏油性之间具有优异的切换润湿性在CO ₂ /N ₂刺激下。该膜可应用于各种油/水系统，包括不混溶混合物、表面活性剂稳定乳液、多相乳液和含污染物乳液，表现出高分离效率（>99.9%）、可回收性和自清洁性能。由于强大的分离性能加上出色的可扩展性，该膜对智能液体分离显示出巨大的影响。