Oil pollution and the energy crisis make oil-water separation an urgent for human need. The widespread use of materials with a single emulsion separation capability is limited. Multifunctional on-demand separation materials can adapt to a wide range of application scenarios, thus having a wider range of applications. The underoil superhydrophilic surface is of great significance for realizing the on-demand separation of oil/water emulsions through the removal of water in the oil and oil in the water. A 3D porous emulsion separation material based on the superhydrophilic principle of sphagnum moss was designed. The material was prepared in a simple step by taking advantage of the adhesion of polydopamine and the introduction of the as-prepared superhydrophilic BaSO₄ nanoparticles to achieve superhydrophilicity with a water contact angle (WCA) of 0° and an oil contact angle (OCA) of 157.3°, resulting in excellent separation performance for both water-in-oil and oil-in-water emulsions. Underoil superhydrophilic porous composite (OSPC) can complete two kinds of emulsion separations by filtration or adsorption. It adsorbs water from water-in-oil emulsion to achieve separation, with a good adsorption capacity of 74.38 g/g and efficiency up to 99%. It can also filter oil-in-water emulsions with an efficiency of 99.92%. The separation efficiencies are all almost unchanged after ten separation cycles. Furthermore, the material has excellent flame retardancy, which reduces the possibility of secondary disasters. The three-dimensional porous sponge has excellent on-demand separation performance for multiple emulsions. It provides a new preparation strategy for underoil superhydrophilic materials and a new idea for the design direction of special wetting materials for the on-demand separation of oil/water emulsions.

石油污染和能源危机使油水分离成为人类的迫切需求。具有单一乳液分离能力的材料的广泛使用受到限制。多功能按需分离材料可以适应广泛的应用场景，从而具有更广泛的应用范围。油下超亲水表面对于通过去除油中水和水中油实现油/水乳液的按需分离具有重要意义。设计了一种基于水苔超亲水原理的3D多孔乳液分离材料。该材料通过利用聚多巴胺的粘附力和引入所制备的超亲水BaSO ₄ 纳米粒子，以简单的步骤制备，以实现水接触角（WCA）为0°和水接触角（WCA）为0°的超亲水性。油接触角（OCA）为157.3°，对油包水和水包油乳液均具有优异的分离性能。 Underoil超亲水多孔复合材料（OSPC）可以通过过滤或吸附完成两种乳液分离。它吸附油包水乳状液中的水而实现分离，吸附容量良好，达到74.38 g/g，效率高达99%。它还可以过滤水包油乳液，效率高达99.92%。十次分离循环后，分离效率几乎没有变化。此外，该材料具有优异的阻燃性，减少了发生次生灾害的可能性。三维多孔海绵对多重乳液具有优异的按需分离性能。 为油下超亲水材料的制备策略提供了新的思路，也为油/水乳液按需分离的特种润湿材料的设计方向提供了新的思路。