Green Approach to the Fabrication of Superhydrophobic Mesh Surface for Oil/Water Separation

Abstract

We report a simple and environment friendly method to fabricate superhydrophobic metallic mesh surfaces for oil/water separation. The obtained mesh surface exhibits superhydrophobicity and superoleophilicity after it was dried in an oven at 200 °C for 10 min. A rough silver layer is formed on the mesh surface after immersion, and the spontaneous adsorption of airborne carbon contaminants on the silver surface lower the surface free energy of the mesh. No low-surface-energy reagents and/or volatile organic solvents are used. In addition, we demonstrate that by using the mesh box, oils can be separated and collected from the surface of water repeatedly, and that high separation efficiencies of larger than 92 % are retained for various oils. Moreover, the superhydrophobic mesh also possesses excellent corrosion resistance and thermal stability. Hence, these superhydrophobic meshes might be good candidates for the practical separation of oil from the surface of water.

Selective separation of oil and water with mesh membranes by capillarity

“…The obtained Ag-coated mesh surface exhibited extreme wetting with a contact angle of 164 ± 1.4°and a sliding angle of 4 ± 0.8°for water, and a contact angle of 0°for kerosene [50]. Here, carbon contaminants from ambient air are spontaneously adsorbed onto the silver surface resulting in superhydrophobicity and superoleophilicity [50]. This Ag nanoparticle based mesh membrane separated oil from water with efficiencies in excess of 92% in repeated cycles [50].…”

“…Here, carbon contaminants from ambient air are spontaneously adsorbed onto the silver surface resulting in superhydrophobicity and superoleophilicity [50]. This Ag nanoparticle based mesh membrane separated oil from water with efficiencies in excess of 92% in repeated cycles [50]. Furthermore, the membrane possessed excellent resistance to corrosion and was stable at temperatures ranging from − 20 to 250°C.…”

“…The surface wettability of pure metals can be altered by surface modification and increasing the roughness [50]. Pure Ag and Cu nanoparticle based mesh membranes have been fabricated for oil and water separation [50][51][52].…”

“…Ag coated meshes were prepared by a simple immersion of copper meshes into an aqueous solution of AgNO 3 at room temperature (Fig. 8) [50]. The obtained Ag-coated mesh surface exhibited extreme wetting with a contact angle of 164 ± 1.4°and a sliding angle of 4 ± 0.8°for water, and a contact angle of 0°for kerosene [50].…”

“…Pure Ag and Cu nanoparticle based mesh membranes have been fabricated for oil and water separation [50][51][52]. Ag coated meshes were prepared by a simple immersion of copper meshes into an aqueous solution of AgNO 3 at room temperature (Fig.…”