Abstract:
In order to achieve the separation of oil-water emulsions and the corrosion resistance of stainless steel meshes, this paper starts from two aspects, namely size screening and wettability, to prepare superhydrophobic and superoleophilic stainless steel meshes to address the difficulties in separating oil-water emulsions and the easy corrosion of samples. A superhydrophobic coating was fabricated on the surface of stainless steel meshes (SSM) by using SiO₂-assisted HF etching and low-cost stearic acid modification methods. According to the “size screening” effect, by etching and modifying stainless steel meshes of different mesh numbers, the influence of meshes with different pore sizes on the emulsion separation effect was investigated, and the pore size of the membrane capable of realizing oil-water emulsion separation was obtained. The optimal etching time was determined by exploring the SiO₂-assisted HF etching state under ultrasonic conditions.The surface micro-morphology, composition, wettability, and corrosion resistance were characterized by SEM, EDS, XRD, a contact angle measuring instrument, and an electrochemical analyzer. The water concentration of the emulsion before and after separation was measured by a Karl Fischer moisture analyzer. The results indicate that the water and oil contact angles of the stainless steel meshes can reach 158° and 0° in air, respectively, showing a superhydrophobic and superoleophilic state. The meshes can achieve the separation of water-in-oil emulsions. Even for emulsions containing surfactants, the separation efficiency remains above 98%, and it also has good seawater corrosion resistance. Therefore, the superhydrophobic and superoleophilic meshes prepared in this paper exhibit excellent separation performance for water-in-oil emulsions and possess seawater corrosion resistance, providing new ideas for the research on emulsion separation meshes with seawater corrosion resistance.