Multimodal Sensing and Self-Healing Supramolecular Coatings for Monitoring of Damage-Healing Dynamics in Anticorrosion Applications

Autonomous self-healing and damage monitoring in protective coatings are of great significance for marine energy devices, ocean-going vessels, and offshore engineering equipment. However, realizing multimodal damage sensing and real-time monitoring of healing dynamics still faces considerable challenges, which arise from the unpredictable nature of microdamage initiation and dynamic property of interfacial healing. Herein, a supramolecular self-healing coating with multimodal damage sensing capability is designed by integrating a conductive polymer layer with a polyurethane (PU) substrate, which enables efficient self-healing and sensitive dynamic electrical signal monitoring. By rationally regulating the PEDOT:PSS conductive network and supramolecular structure, the microfailure information on coating damage (wear, impact, crack) and interfacial healing dynamic behaviors can be converted and amplified into easily detectable electrical signals, enabling the real-time and dynamic monitoring of interfacial evolution behavior, capable of sensing cracks as small as 0.33 μm in width. Based on multiple hydrogen bonds and dynamic disulfide bonds in the polyurethane (PU) matrix, the smart coating possessed superior self-healing efficiency (93%), high tensile strength (41.49 MPa), and a relatively high impedance value (1.66 × 10 10 Ω·cm 2 ). Therefore, this smart coating system not only possesses damage-healing capabilities and anticorrosion performance but also breaks through the technical limitations of traditional coatings that cannot dynamically track interface failures, providing a material solution with application potential for coating health monitoring and life prediction in marine environment.