Self-healing and fluorescent anti-corrosion coatings for aluminum alloys

Aluminum alloys commonly used in ship hulls and underwater vehicles face severe corrosion in marine environments. Self-healing coatings, capable of autonomously repairing damage, are a focus of recent research developments. This article details the development of such a coating, employing fluorescence for damage indication and shape memory polymers for self-healing. A fluorescent probe (rhodamine-naphthalimide) was synthesized and embedded in fibers made from a specialized polymer using coaxial electrospinning technology. These fibers, containing the fluorescent solution, were integrated into epoxy coatings.

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The coating responds to mechanical damage with a fluorescent signal, activated by water and Al3+ ions, and uses infrared laser targeting to identify and repair specific points of damage. When infrared triggers a localized temperature change, the polymer’s shape memory function activates, causing the damaged area to soften, expand, and autonomously heal. This approach highlights the potential for improved corrosion protection in aluminum alloys, advancing the development of smart coatings.

Source: Journal of Coatings Technology and Research, Vol. 21, pp. 1431–1446 (2024).