Anti-corrosion enhancement of superhydrophobic coating utilizing oxygen vacancy modified potassium titanate whisker

Anti-corrosion polymer coatings are commonly used for metal to form a barrier against the corrosion medium. However the anti-corrosion performance of many polymer coatings is unavoidably degraded owing to the long-term permeation of corrosion media. Many researches have attempted to inhibit this permeation process and enhance the corrosive protecting performance. In this study, a novel polyethersulfone (PES) superhydrophobic coating with long-term anti-corrosion ability for carbon steel was developed by utilizing reduced potassium titanate whisker (RPTW), nano-SiO2 and 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (POTS). Oxygen vacancies were generated on the RPTW owing to the reducing reaction at a low temperature. Then, for the first time, the RPTW was used to passivate the carbon steel substrate in coating by generating and transferring atomic oxygen through oxygen vacancies, providing an additional protection layer to shield the metal substrate against the corrosion medium. Moreover, 6% RPTW and 3% nano-SiO2 formed an excellent superhydrophobic surface with the addition of POTS. The air film captured on the super-hydrophobic surface inhibited the diffusion of water and ions. Therefore, in combination with the air film and the dense Fe3O4 passive film generated via a novel method, the PES superhydrophobic coating exhibited a stable impedance two orders of magnitude higher than that of the normal PTW reinforced PES coating.