A robust superhydrophobic coating with multi-dimensional micro-nano structure on 5052 aluminum alloy

Abstract

This paper presents a new method to constructing a robust superhydrophobic surface with multi-dimensional roughness on 5052 aluminum alloy (SHC-Al). The microstructure and surface properties of the SHC-Al were investigated using various techniques including Field emission scanning electron microscope (FESEM), Energy dispersive X-ray spectroscopy (EDS), Laser confocal scanning microscope (CLSM), Fourier transform infrared spectrometer (FTIR), X-ray diffractometer (XRD), Contact angle measuring instrument and electrochemical techniques. The findings indicated that the surface had a hierarchical flower-like micro-nano rough structure, with a water contact angle (WCA) of 162.4° and a rolling angle (SA) of 3.2°, making it easy to clean. Furthermore, the superhydrophobic property can be restored after 90 wear cycles or 33 tape stripping. Electrochemical results demonstrated that the coating had a low corrosion current of 2.742 × 10−9 A·cm−2. The coating remained effective in preventing corrosive mediums from reaching 5052 aluminum surface after soaking in 3.5 wt% NaCl solutions for 72 h, with a coating protection efficiency of 97.9 %, demonstrating excellent anticorrosion properties. Additionally, the coating showed exceptional stability. The results demonstrate that the as-prepared superhydrophobic surface is robust and corrosion-resistant, which hold great promise for practical applications.