UV laser-produced copper micro-mesh with superhydrophobic-oleophilic surface for oil-water separation

We report a method to fabricate micro-pore arrays on a copper sheet by a 355 nm UV nanosecond pulse laser, and investigate the effects of surface microstructures and micropore spacing on the wettability of the formed copper micro-mesh. We found that the surface was initially hydrophilic, but changed to superhydrophobic-oleophilic with water contact angle 151 degrees and oil contact angle about 10 degrees after exposed to ambient environment for 14 days. We analysed the surface morphologies of the processed samples with a three-dimensional profilometer, measured the water and oil contact angles, and characterized the surface by a field emission environmental scanning electron microscope (FESEM) and energy dispersive X-ray spectrometer (EDS). The surface chemistry changes were confirmed by X-ray photographic spectroscopy (XPS). Effective oil-water separation performance of the fabricated copper mesh was demonstrated. Learning from the natural change, we designed a coating material containing C8 long C-C (H) chain and coated onto the freshly prepared copper mesh to convert the surface property into a preferred superhydrophobic-oleophilic nature. This study provides a controllable methodology consisting laser processing and surface modification for making micro-pore copper mesh as a simple and effective method for oil-water separation. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

A method for fabricating micro-pore arrays on a copper sheet and modifying the surface properties for superhydrophobic-oleophilic nature was reported. A coating material containing C8 long chains was designed to convert the surface property of the copper mesh. This controllable methodology showed effective oil-water separation performance.