Synthesis of inhibitor nanocontainers with two-dimensional structure and their anticorrosion action in sol-gel coating on AA2024-T3 aluminum alloy

The synthesis of inhibitor nanocontainers with two-dimensional (2D) structure using graphene oxide and layered double hydroxides (GO/LDHs) via a coprecipitation method was studied. The corrosion inhibitors of vanadate anions (VO_x⁻) and 2-mercaptobenzothiazole anions (MBT⁻) were loaded into the GO/LDHs nanocontainers by an anion exchange reaction and the products retained the 2D structure. GO/LDHs loaded with VO_x⁻ (GO/LDHs-VO_x⁻) were added into a sol-gel coating on AA2024-T3. It was found that the corrosion protection of the sol-gel coating was effectively enhanced. No serious corrosion was observed on the alloy after 240 h of salt spray test. The enhancement of the protective properties was attributed to two aspects: the improvement of the barrier property from the good dispersion of the additive with the 2D structure and the good barrier of GO sheets, and the corrosion inhibition of vanadate anions. In other words, the protection mechanism was that GO/LDHs-VO_x⁻ provided the coating active and improved passive protection simultaneously.