Fabrication and characterization of self-assembled graphene oxide/silane coatings for corrosion resistance

Flexible barrier films preventing corrosion are important for many industries ranging from engineering to medical to electronic materials. In order to improve the corrosion resistance ability of GO-based composite films, the Bis[3-(triethoxysilyl)propyl]tetrasulfide (BTESPT)/GO multi-layered films were layer by layer self-assembled on the surface of 2024 aluminum alloy (AA 2024). The results showed that the designed composite films obviously improved the corrosion resistance ability of AA2024 substrate. The composite films, especially for the middle GO layer, effectively hinders the corrosion reaction by reducing the rate of both the cathodic and the anodic reactions. Furthermore, the formation of Si-O-C covalent bonds based on the XPS analysis implies the improved binding force between silane film and the fabricated middle GO layer. After 40 days immersion in 3.5% NaCl solution, the composite films still had better corrosion resistance ability, which implied the fabricated composite films had better resistance to penetration ability for corrosive ions, and the corrosion mechanism was also analyzed for the long-term immersion process based on the EIS results.