Wettability and electrochemical properties of the highly hydrophobic coatings on PEO-pretreated aluminum alloy

Morphology, composition, and barrier properties of superhydrophobic (SHP) coatings on the surface of AMg3 aluminum alloy pretreated by plasma electrolytic oxidation (PEO) have been investigated. Results of the study of hydrophobic layers on aluminum alloy, which underwent plasma electrolytic oxidation (PEO) and additional treatment under UV-radiation in the presence of ozone plasma with subsequent deposition of the hydrophobic agent (methoxy-{3-[(2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluoroctyl)oxy]propyl}-silane solution in decane), have been described. Coatings formed by deposition of dispersion of the hydrophobic agent containing SiO2 nanoparticles on the surface of the PEO-layer are characterized by high contact angles and inhibitive properties. The formed composite layers were found to be characterized with hydrophobicity (contact angle higher than 157°) and high barrier properties (the impedance modulus, | Z |f = 0.01 Hz, ranges from 9.2 × 109 to 1.1 × 1011 Ω cm2 depending on the treatment procedure).