Fabrication of Superhydrophobic Copper Using via Chemical Etching and Modification Route

Abstract

Biological superhydrophobic surfaces are relative common in the nature. Inspired from the superhydrophobic property, plentiful materials with the hydrophobic surfaces have been fabricated for various applications such as anti-corrosion, anti-icing, self-cleaning, friction reduction, oil-water separation. In the present work, we report a scalable, simple, and rapid method to fabricate superhydrophobic film on copper substrates via a simple route including a chemical etching step in sodium persulfate and sodium hydroxide solution and followed by a modification step in stearic acid solution. Effect of the etchants concentration as well as etching time was investigated exhaustively. From the obtained measurement results it was found that, when a copper plate was etched in the etching solution of the low etchants concentration the contact angle of copper was influenced dramatically by the etching time. In contrast, at the high concentration condition of the etchants, the etching time hardly affected on the contact angle of the copper plate. Superhydrophobic feature of the copper surface (with the contact angle larger than 150o) only achieved in some certain fabrication conditions. At optimized fabrication conditions, the superhydrophobic copper substrates demonstrated high anti-corrosion higher about 85 times than the pristine one. In addition, the as-prepared superhydrophobic copper mesh was used to successfully separate toluene from its aqueous mixture, proving the high application potential of the superhydrophobic copper in oil-water separation and anti-corrosion in aqueous environments.