Influence of Embedded Nanocontainers on the Efficiency of Active Anticorrosive Coatings for Aluminum Alloys Part I: Influence of Nanocontainer Concentration

This work presents an effective anticorrosive coating for the industrially important aluminum alloy, AA2024-T3. The protective coating was designed by dispersing mesoporous silica nanocontainers, loaded with the nontoxic corrosion inhibitor, 2-mercaptobenzothiazole, in a hybrid sol-gel (SiOx/ZrOx) layer. The concentration of the embedded nanocontainers was varied (0.04-1.7 wt %) to ascertain the optimum conditions for anticorrosion performance. Attaining high efficiency was found to be a compromise between delivering sufficient corrosion inhibitor and preserving the coating barrier properties. The impact of nanocontainer concentration on the thickness and adhesion of freshly cured coatings was also investigated. The barrier properties of the intact coatings were assessed by electrochemical impedance spectroscopy. The active corrosion inhibition was evaluated during a simulated corrosion process by the scanning vibrating electrode technique. This study has led to a better understanding of the factors influencing the anticorrosion performance and properties of active anticorrosive coatings with embedded nanocontainers.