Effect of surface treatment on wetting behavior of copper

Abstract

Super-hydrophobic surfaces are very useful in cleaning activities. Surfaces with water contact angles above 150° are regarded as superhydrophobic surfaces. In the present study an attempt has been made to achieve superhydrophobicity on copper substrate by electrochemical etching and electro-deposition of Co-Ni alloy and Co-Ni-Graphene composite. A contact angle of about 105° was obtained on Cu surface with electro-deposited Co-Ni alloy and on electro-deposited Co-Ni-G alloy contact angle was found to be 106°. The contact angle was significantly higher at about 142° with electro etched surface. Corrosion test was carried out with electrochemically etched Cu. Electrochemical etching time was varied from 30 to 240 min. The electro-etched Cu substrate etched for 60 min. showed better corrosion resistance with a corrosion rate of 0.197 mm/year. The surface topography of both etched and electrodeposited samples was studied by atomic force microscopy (AFM) and the results were correlated with the wettability data. © 2019 Elsevier Ltd.