Photothermal nanofiller-based polydimethylsiloxane anticorrosion coating with multiple cyclic self-healing and long-term self-healing performance

[Display omitted] •Metal coordination bonds improve interfacial bonding of coating and nanofillers.•The PDMS-Cu2O@Ag coating has excellent multiple cyclic self-healing performance.•The coating has excellent long-term self-healing and anticorrosion performance.•Protection mechanism was analyzed by the cooperation of DRT and equivalent circuit. Self-healing coating is a new strategy for improving the service life of the anticorrosion coating, however, remaining a challenge to achieve stable, multiple cyclic, and long-term self-healing performances of the anticorrosion coating. Herein, a multiple cyclic self-healing and long-term self-healing polydimethylsiloxane coating reinforced by Cu2O@Ag nanofillers was reported. The metal coordination bond, formed between cooper of nanofillers and nitrogen of basal coating, provides good interfacial compatibility between nanofillers and coating, and improve the self-healing performance of the coating for its dynamic reversible process. In addition, the photothermal test indicated that the formation of metal coordination bond improves the photothermal properties and the PDMS-Cu2O@Ag coating had excellent photothermal stability, which provides the possibility of long-term self-healing performance. The scratch and self-healing cyclic tests at the initial stage of immersion and after 80 days of immersion were carried out respectively, which indicated that the coating owned excellent multiple cyclic self-healing and long-term self-healing abilities. Furthermore, the distribution of relaxation time analysis mothed analyzed the anticorrosion process of the coating. The distributions of two kinds of charge transfer processes in the cyclic tests owned different contributions, revealing the anticorrosion mechanism in the self-healing process of the coating. This work would open a new avenue for boosting the multiple cyclic self-healing and long-term self-healing coating performance.