Anticorrosive composite self-healing coating enabled by solar irradiation

Self-healing coatings for long-term corrosion protection have received much interest in recent years. However, most self-healing coatings rely on healants released from microcapsules, dynamic bonds, shape memory, or thermoplastic materials, which generally suffer from limited healing times or harsh conditions for self-healing, such as high temperature and UV radiation. Herein, we present a composite coating with a self-healing function under easily accessible sunlight by adding Fe3O4 nanoparticles and tetradecanol into epoxy resin. Tetradecanol, with its moderate melting point, and Fe3O4 nanoparticles serve as a phase-change component and photothermal material in an epoxy coating system, respectively. Fe3O4 nanoparticles endow this composite self-healing coating with good photothermal properties and a rapid thermal response time under simulated solar irradiation as well as outdoor real sunlight. Tetradecanol can flow to and fill defects by phase transition at low temperatures. Therefore, artificial defects created in this type of self-healing coating can be healed by the liquified tetradecanol induced by the photothermal effect of Fe3O4 nanoparticles under simulated solar irradiation. The healed coating can still serve as a good barrier for the protection of the underlying carbon steel. These excellent properties make this self-healing coating an excellent candidate for various engineering applications.

Automated summary

A composite coating with self-healing function under accessible sunlight was developed by incorporating Fe3O4 nanoparticles and tetradecanol into epoxy resin. The Fe3O4 nanoparticles exhibited excellent photothermal properties and rapid thermal response under simulated solar irradiation. The tetradecanol can flow and fill defects through phase transition at low temperatures. The healed coating effectively protected the underlying carbon steel, making it a promising candidate for various engineering applications.