Khan Sharjeel Ahmed, Ialyshev Vadim, Kim Vyacheslav V, Iqbal Mazhar, Al Harmi Hamad, Boltaev Ganjaboy S, Ganeev Rashid A, Alnaser Ali S
Department of Physics, American University of Sharjah, Sharjah, United Arab Emirates.
Faculty of Physics, Voronezh State University, Voronezh, Russia.
Front Chem. 2020 Sep 29;8:768. doi: 10.3389/fchem.2020.00768. eCollection 2020.
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.
利用超润湿性以及膜对油或水的选择性渗透性进行油水分离具有重大的生态和经济意义。我们报告了通过使用超短飞秒激光脉冲对不锈钢网和铜网进行纳米结构化，使润湿性响应从水下超亲水性-超疏油性转变为超疏水性-超亲油性状态。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对处理后的样品进行时效处理的优势。我们优化了激光扫描参数、网孔尺寸和时效条件，以制备对油水混合物具有98%的非凡分离效率的膜。给出了不同网的水和油接触角随激光扫描速度的变化情况。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优异的润湿性响应。在没有水分子的情况下，真空时效会导致碳氢化合物在激光结构化表面上快速化学吸附，迅速将润湿状态从超亲水性转变为超疏水性。
