Novel copper-based nanocomposite coatings achieving autonomous damage reporting and solar-triggered self-healing for marine corrosion protection

Abstract

Developing efficient self-healing corrosion-resistant coatings remains a major challenge in metal protection. Herein, we propose a novel micron/nano-scale strategy to fabricate core-shell composite nanofibers (PVB-PVP-Cu₂(OH)₃NO₃@Phen) via a one-step coaxial electrospinning process. The in-situ growth photothermal agent Cu₂(OH)₃NO₃ (CON) and corrosion indicator phenanthroline (Phen) are simultaneously integrated, forming a multifunctional system. Remarkably, this work reports the first successful in situ synthesis of CON nanoparticles through one-step electrospinning, with the photothermal conversion mechanism corroborated through both experimental and simulation approaches. Integrated into a thermal-responsive epoxy resin, the composite nanofibers enable autonomous corrosion detection and photothermal-triggered self-healing, markedly enhancing both healing efficiency and corrosion protection. The BP-CON@Phen/EP coating rapidly heats to 61.0 °C under simulated sunlight within 200 s, promoting chain mobility and achieving a 95.04 % self-healing efficiency. After 140 days of immersion, the coating maintains strong protective properties with a stable impedance of 5.3 × 10⁸ Ω cm². Additionally, BP-CON@Phen enhances the resistance of the epoxy coating to temperature fluctuations and cathodic disbondment. Molecular dynamics simulations further indicate that BP-CON@Phen effectively obstructs corrosive media penetration, sustaining long-term corrosion resistance. This novel design strategy holds significant potential for advancing self-healing and corrosion-resistant coatings, offering high-performance solutions for diverse surface protection applications.