Achieving Hierarchical and Multi-Scale Structure Onto Cu Substrate with Superhydrophobicity and Enhanced Anti-Corrosion Via Electrochemical Etching and Heat Treatment Mechanism

Abstract

In this work, superhydrophobic surfaces with hierarchical and multi-scale micro/nanostructure was fabricated by a simple method without damaging the substrate material. Electrochemical etching and heat treatment were taken to adhere the robust electroplated Ni with the excellent hydrophobic material of polydimethylsiloxane (PDMS) to provide a double-layer protection for the bare Cu substrate. The as-prepared superhydrophobic surface exhibited a high contact angle (CA) of 158.5° and a low slide angle (SA) of 2.4°. Electrochemical corrosion test results showed the corrosion current density of superhydrophobic surface was about 4 orders of magnitude lower than that of bare Cu in 3.5 wt.% NaCl solution, indicating that the superhydrophobic surface had superior corrosion resistance. We also discussed the corrosion resistance mechanism of superhydrophobic surface with hierarchical and multi-scale micro/nanostructure. In addition, good mechanochemical and self-cleaning properties provide effective support for the practical application of superhydrophobic surface.

Keywords: Superhydrophobic surface, Hierarchical structure, Mechanochemical stability, corrosion resistance, self-cleaning