Fabrication of superhydrophobic coatings for corrosion protection by electrodeposition: A comprehensive review

In recent years, superhydrophobic materials have shown tremendous industrial application value in many fields. Especially in the field of anti-corrosion, the superhydrophobic coating can capture the air to form many "air bags" on the surface of the substrate, so it has a strong water-repellent ability, thus isolating the corrosion media and achieving remarkable anti-corrosion performance. Various preparation technologies of superhydrophobic coatings have been proposed, but each has its own defects. As a relatively mature industrial processing method, electrodeposition shows unique advantages. However, there are few reviews on the preparation of anticorrosive superhydrophobic coatings by electrodeposition till now. In this paper, the general theory of superhydrophobic surface, including factors affecting wettability and theoretical wetting models, is firstly reviewed. Secondly, the mechanism, application status and anti-corrosion performance of superhydrophobic coatings prepared by metal electrodeposition, non-metallic electrodeposition, and composite electrodeposition are summarized in detail, respectively. The internal mechanism of process conditions, especially crystal modifiers, to regulate the coating morphology is described. Moreover, new developments over the years in electrodeposition such as pulse electrodeposition, magnetic field-induced electrodeposition, ultrasonic-assisted electrodeposition for the fabrication of superhydrophobic coatings are also presented. Finally, the deficiency of this technology is pointed out, and the future research directions of improving the durability of superhydrophobic coatings are proposed.