The article reports the development of hygro-responsive membranes with superhydrophilic and superoleophobic surfaces, capable of separating various oil-water mixtures with >99.9% efficiency. These membranes are designed to be both superhydrophilic and superoleophobic in air and under water, allowing for effective separation of different types of oil-water mixtures using gravity-driven capillary force-based separation (CFS). The membranes are prepared by dip-coating or spin-coating a blend of PEGDA and fluorodecyl POSS onto stainless steel mesh or polyester fabric, followed by cross-linking. The membranes exhibit surface reconfiguration under water, enhancing their oleophobicity. Experiments demonstrate the successful separation of oil-in-water and water-in-oil emulsions, free oil and water, and four-component mixtures, with high purity and efficiency. The continuous operation of the separation apparatus is also described, achieving stable and efficient separation over extended periods. The authors anticipate that this technology will have applications in oil spill cleanup, wastewater treatment, fuel purification, and the separation of commercially relevant emulsions.The article reports the development of hygro-responsive membranes with superhydrophilic and superoleophobic surfaces, capable of separating various oil-water mixtures with >99.9% efficiency. These membranes are designed to be both superhydrophilic and superoleophobic in air and under water, allowing for effective separation of different types of oil-water mixtures using gravity-driven capillary force-based separation (CFS). The membranes are prepared by dip-coating or spin-coating a blend of PEGDA and fluorodecyl POSS onto stainless steel mesh or polyester fabric, followed by cross-linking. The membranes exhibit surface reconfiguration under water, enhancing their oleophobicity. Experiments demonstrate the successful separation of oil-in-water and water-in-oil emulsions, free oil and water, and four-component mixtures, with high purity and efficiency. The continuous operation of the separation apparatus is also described, achieving stable and efficient separation over extended periods. The authors anticipate that this technology will have applications in oil spill cleanup, wastewater treatment, fuel purification, and the separation of commercially relevant emulsions.