Oil-water separation using super-wetting and the selective permeability of membranes for oil or water has great ecological and economic significance. We report on the transition of wettability response, from superhydrophilic underwater-superoleophobic to superhydrophobic-superoleophilic state, by nanostructuring stainless steel and copper meshes using ultrashort femtosecond laser pulses. Our approach is environment-friendly, chemical free, and efficient as it exploits the benefit of aging the processed samples in a high vacuum environment. We optimized the laser scanning parameters, mesh pore size, and aging conditions to produce membranes exhibiting an extraordinary separation efficiency of 98% for the oil-water mixture. A variation in the water and oil contact angles for different meshes is presented as a function of the laser scanning speed. Stainless steel meshes with 150 μm pore size and copper meshes with 100 μm pore size have demonstrated an excellent wettability response for oil and water phases. Vacuum aging causes rapid chemisorption of hydrocarbons on laser-structured surfaces in the absence of water molecules, rapidly transforming the wetting state from superhydrophilic to superhydrophobic.

利用超湿法进行油水分离以及膜对油或水的选择性渗透具有重要的生态和经济意义。我们报告了通过使用超短飞秒激光脉冲对不锈钢和铜网进行纳米结构化，从超亲水的水下超疏油状态到超疏水的超亲油状态的润湿性响应的转变。我们的方法是环境友好，无化学物质且高效的，因为它利用了在高真空环境中老化已处理样品的好处。我们优化了激光扫描参数，筛孔尺寸和老化条件，以生产出对油水混合物具有98％的非凡分离效率的膜。给出了不同网格的水和油接触角的变化与激光扫描速度的关系。孔径为150μm的不锈钢网和孔径为100μm的铜网对油相和水相表现出出色的润湿性。真空老化会导致在不存在水分子的情况下，碳氢化合物在激光结构化表面上的快速化学吸附，从而将润湿状态从超亲水性迅速转变为超疏水性。