Enhancement of Active Corrosion Protection via Combination of Inhibitor-Loaded Nanocontainers

TLDR

The study synthesizes layered double hydroxide nanocontainers loaded with vanadate, phosphate, and 2‑mercaptobenzothiazolate inhibitors and characterizes them by XRD and TEM. The authors evaluate the anticorrosion performance of these nanocontainers on aluminum alloy AA2024 using electrochemical impedance spectroscopy, immersion tests in NaCl, and incorporation into commercial aeronautical coatings to probe inhibition mechanisms and efficiency. Combining nanocontainers loaded with different inhibitors in a single protective coating enhances active corrosion protection of the alloy.

Abstract

The present work reports the synthesis of layered double hydroxides (LDHs) nanocontainers loaded with different corrosion inhibitors (vanadate, phosphate, and 2-mercaptobenzothiazolate) and the characterization of the resulting pigments by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The anticorrosion activity of these nanocontainers with respect to aluminum alloy AA2024 was investigated by electrochemical impedance spectroscopy (EIS). The bare metallic substrates were immersed in dispersions of nanocontainers in sodium chloride solution and tested to understand the inhibition mechanisms and efficiency. The nanocontainers were also incorporated into commercial coatings used for aeronautical applications to study the active corrosion protection properties in systems of industrial relevance. The results show that an enhancement of the active protection effect can be reached when nanocontainers loaded with different inhibitors are combined in the same protective coating system.