Active Anticorrosion Coatings with Halloysite Nanocontainers

Abstract

This work contributes to the development of a new generation of active corrosion protection coatings composed of hybrid sol−gel films doped with halloysite nanotubes able to release entrapped corrosion inhibitors in a controllable way. A silica-zirconia-based hybrid film was used in this work as an anticorrosion coating deposited on 2024 aluminum alloy. Halloysite nanotubes with inner voids loaded by corrosion inhibitors (2-mercaptobenzothiazole) and outer surfaces layer-by-layer covered with polyelectrolyte multilayers were introduced into the hybrid films. The sol−gel film with the nanocontainers reveals enhanced long-term corrosion protection in comparison with the undoped sol−gel film. This effect is obtained because of the self-controlled release of the corrosion inhibitor triggered by the corrosion processes. Utilization of the inner halloysite nanotube lumen as a storage medium for the corrosion inhibitor offers a novel way of fabricating composite core−shell type nanomaterials with their further application as a main component of feedback-active coatings.