Construction of multilayer superhydrophobic film on Al alloy and corrosion resistance mechanism

Abstract

The higher corrosion rates of aluminum alloys limit applications. In order to provide the service life, this paper uses anodic oxidation as a transition layer, adopts the layer-by-layer self-assembly technology was used to prepare anodized/perfluorooctyltriethoxysilane (POTS)/polypropylene (PP) (APP) composite films on aluminum alloys, and the film-forming mechanism was studied by molecular dynamics simulation and quantum chemical calculation. The APP composite film has excellent superhydrophobicity (contact angle of 157°), thermal shock stability and abrasion resistance. Electrochemical tests show that the resistance value of the super-hydrophobic composite film is increased from 10³ to 10⁹ Ω cm², and the corrosion current density is reduced from 10⁻⁵ to 10⁻⁹ A/cm². Acid-base test and salt spray test show excellent corrosion resistance and stability, can be widely used in complex environments, and have broad application prospects.