Facile Repair of Anti-Corrosion Polymeric Composite Coatings Based on Light Triggered Self-Healing

Photothermally induced self-healing coatings are widely reported, while their application scenarios are rarely taken with concern. In addition, there is a need to achieve the balance between good properties and self-healing behaviors for closing the gap between academic research and engineering applications. Here, self-healing composite coatings are designed based on silane-modified epoxy chains with reversible crosslinking points and multifunctional fillers of cerium oxide nanoparticles grown on graphene nanosheets, and their applications are demonstrated for restricted regions. Diglycidyl ether-terminated poly(dimethylsiloxane) is co-polymerized with diglycidylether of bisphenol A with the weight ratio of 1/99–10/90 to achieve surface-tension driven crack closure, while dangling furan groups contribute to reversible crosslinking points via Diels–Alder reaction. Cerium oxide nanoparticles and graphene nanosheets enhance anti-corrosion properties, and graphene nanosheets also act as photothermal fillers. The results show that pencil hardness, polarized resistance, and coating resistance are highly improved via the introduction of multifunctional fillers at 1 and 2 phr. Good thermally and photothermally induced self-healing is demonstrated. This work provides a new application thought for light triggered self-healing coatings that can be used for restricted regions including inner walls of pipelines and reactors.