Superhydrophilic-underwater superoleophobic ZnO-based coated mesh for highly efficient oil and water separation

Synergistic superhydrophilic-underwater superoleophobic meshes were fabricated by spraying ZnO nanoparticles and polyurethane mixtures on stainless steel mesh substrates. The coated meshes were then used to study gravity-driven oil/water separation for a series of oil/water mixtures, where only the water permeate through the mesh while the oil is repelled on the mesh. Separation efficiency up to 99.0% could be achieved through the coated mesh for the kerosene-water mixture. Moreover, the as-prepared coated mesh still maintained high separation efficiency and stable recyclability after 50 separation cycles with the separation efficiency for the kerosene-water mixture always above 97.3%. The fabrication approach presented here can be applied for coating large surface areas and to develop a large-scale oil/water separation facility for oil-field applications and petroleum industries. (C) 2015 Elsevier B.V. All rights reserved.