Nanosecond Laser-Induced Underwater Superoleophobic\nand Underoil Superhydrophobic Mesh for Oil/Water Separation

Abstract

Materials\nwith special wettability have drawn considerable attention\nespecially in the practical application for the separation and recovery\nof the oily wastewater, whereas there still remain challenges of the\nhigh-cost materials, significant time, and complicated production\nequipment. Here, a simple method to fabricate the underwater superoleophobic\nand underoil superhydrophobic brass mesh via the nanosecond laser\nablation is reported for the first time, which provided the micro-/nanoscale\nhierarchical structures. This mesh is superhydrophilic and superoleophilic\nin air but superoleophobic under water and superhydrophobic under\noil. On the basis of the special wettability of the as-fabricated\nmesh, we demonstrate a proof of the light or heavy oil/water separation,\nand the excellent separation efficiencies (>96%) and the superior\nwater/oil breakthrough pressure coupled with the high water/oil flux\nare achieved. Moreover, the nanosecond laser technique is simple and\neconomical, and it is advisable for the large-area and mass fabrication\nof the underwater superoleophobic and underoil superhydrophobic mesh\nin the large-scale oil/water separation.