Anticorrosion Coatings with Self-Healing Effect Based on Nanocontainers Impregnated with Corrosion Inhibitor

The development of active corrosion protection systems for metallic substrates is an issue of prime importance for many industrial applications. The present work shows a new contribution to the development of a new protective system with self-healing ability composed of hybrid sol−gel films doped with nanocontainers that release entrapped corrosion inhibitor in response to pH changes caused by corrosion process. A silica−zirconia based hybrid film was used in this work as an anticorrosion coating deposited on 2024 aluminum alloy. Silica nanoparticles covered layer-by-layer with polyelectrolyte layers and layers of inhibitor (benzotriazole) were randomly introduced into the hybrid films. The hybrid film with the nanocontainers reveals enhanced long-term corrosion protection in comparison with the undoped hybrid film. The scanning vibrating electrode technique also shows an effective self-healing ability of the defects. This effect is obtained due to regulated release of the corrosion inhibitor triggered by the corrosion processes started in the cavities. The approach described herein can be used in many applications where active corrosion protection of materials is required.