Bioinspired Underwater Superoleophobic Membrane Based on a Graphene Oxide Coated Wire Mesh for Efficient Oil/Water Separation

Abstract

Inspired from fish scales that exhibit unique underwater superoleophobicity because of the presence of micronanostructures and hydrophilic slime on their surface, we reported here the facile fabrication of underwater superoleophobic membranes by coating a layer of graphene oxide (GO) on commercially available wire meshes with tunable pore sizes. Using the wire mesh as a ready-made mask, GO-embellished mesh with open apertures (GO@mesh) could be readily fabricated after subsequent O2 plasma treatments from the back side. Interestingly, the congenital microstructures of the crossed microwires in combination with the abundant hydrophilic oxygen-containing groups of the GO layer endow the resultant GO@mesh with unique underwater superoleophobic properties. The antioil tests show that the underwater contact angles of various oils including both organic reagents (undissolved in water) and vegetable oil on GO@mesh exceed 150°, indicating the superoleophobic nature. In a representative experiment, a mixture of bean oil and water that imitates culinary sewage has been well separated with the help of our GO@mesh. GO-embellished wire meshes may find broad applications in sewage purification, especially for the treatment of oil contaminations.

Keywords: bioinspired; fish scale; graphene oxide; oil/water separation; underwater superoleophobic; wire mesh.