Wetting and corrosion properties of CuxOy films deposited by magnetron sputtering for maritime applications

Copper-based materials can be safe and economic alternatives for producing anti-biofouling coatings for large-scale applications. Although their antibiofouling properties have been previously described, the wetting and corrosion properties in specific environments such as the maritime industry has been far less explored.In this study, copper oxide (CuxOy) films were deposited by a DC reactive magnetron sputtering technique on stainless steel substrates. The oxygen amount during deposition was varied to obtain different structures. The films were characterised by SEM, EDS, XRD, AFM, and contact angle measurements. Oxygen incorporation into copper films promoted a significant change in the growth profile of the film, from dense and undefined grains to columnar grains with well-defined boundaries. Wettability results demonstrate that CuxOy films are high dispersive surfaces with poor affinity with seawater. Corrosion tests were performed in an NaCl (3.5% wt.) solution during 24 h through EIS and potentiodynamic polarization. The films were chemically characterized before and after corrosion tests by XPS as well as their ionic releasing process by ICP-OES spectroscopy. CuxOy coatings exhibited a poor corrosion resistance against artificial seawater and high ionic (Cu2+) release, which suggests a diffusion process. The results give insights into the chemical resistance of CuxOy films for application to avoid biofouling under seawater exposure.

Automated summary

Copper-based materials can be safe and economic alternatives for producing anti-biofouling coatings. This study shows that oxygen incorporation into copper films can change their growth profile, and CuxOy coatings exhibit poor corrosion resistance and high ion release in seawater.