Superhydrophobic copper coating with ultrahigh corrosion resistance by electrodeposition process in a deep eutectic solvent

Preparation of Superhydrophobic Surfaces Based on Copper Mesh Substrates and Its Application Performance

“…Corrosion tests were carried out on bare copper and superhydrophobic coatings in 3.5 wt % NaCl solution. The corrosion current density of the superhydrophobic coating was the lowest at 4.28 × 10 –7 A/cm 2 compared to the corrosion current density of bare copper (2.27 × 10 –6 A/cm 2 ) . Jia et al used a 0.1 mm flat-bottom sharp knife to mill the surface of a Cu substrate in a CNC engraving machine to construct the microstructure of rectangular bumps.…”

“…The corrosion current density of the superhydrophobic coating was the lowest at 4.28 × 10 −7 A/cm 2 compared to the corrosion current density of bare copper (2.27 × 10 −6 A/cm 2 ). 14 Jia et al used a 0.1 mm flat-bottom sharp knife to mill the surface of a Cu substrate in a CNC engraving machine to construct the microstructure of rectangular bumps. A superhydrophobic surface was obtained after the stearic acid modification.…”

“…According to Young’s equation, solid surfaces with water contact angle (WCA) θ < 90° are hydrophilic; while solid surfaces with WCA θ > 90° are hydrophobic, and superhydrophobic surfaces have WCA θ > 150° . There are two main traditional ways to obtain superhydrophobic surfaces: increasing surface roughness and decreasing surface energy . According to these two principles, the main methods to prepare superhydrophobic surfaces are etching, , hydrothermal, anodization, electrochemical deposition, − milling method, sol–gel method, and in situ growth. , However, there are many methods proposed in the research with complicated steps and experimental setups, such as ultrasonic etching technique to obtain copper mesh surfaces with parabolic-like rough structure by Qiao et al, or limited by certain substrates and expensive raw materials, such as the sol–gel method for polyethylene glycol ethylene terephthalate (PET) filters using ethyl orthosilicate (TEOS) as the precursor and perfluorodecyltriethoxysilane (PFDTES) as the modifier adopted by Dong et al Yuan et al used the backside of a fresh bamboo leaf as the original template, and by combining the template on a copper foil, a regular multiscale layered structure was prepared on the copper foil; after further treatment with stearic acid, the sample had superhydrophobic properties with a WCA of 160°.…”

A novel route to fabricate a superhydrophobic surface on a copper substrate without additional low surface energy materials

“…Under the condition of 2000# sandpaper and the load of 10 g, the superhydrophobic sample maintains a large WCA of 155.41 after abrasion of 20 cm. Until the sliding distance increased to 150 cm, the oxide surface continued to demonstrate the superhydrophobic performance, indicating a better mechanical stability than the surface modified by stearic acid in the literature 15 and palmitic acid in Fig. S5 (ESI †).…”

“…Compared with the bare and heat-treated copper, the superhydrophobic sample displays a more positive E corr and lower j corr , which indicates a weaker corrosion tendency and slower corrosion rate. 13,14 From the results listed in Table S1 (ESI†), it also could be inferred that the heat treated sample displayed a better mechanical stability than the copper surface modified by stearic acid 15 and dodecanethiol. 16…”