Three birds with one stone: Contemporaneously boosting passive, active and self-healing properties for long-term anticorrosion coatings

Abstract

Stimuli-responsive coatings can self-repair their own anticorrosion function in response to environmental changes, but they do not exhibit ideal long-term protective effect due to the lack of ability to regulate corrosive media, while this is vital to practical metal protection. Inspired by catalytic oxygen reduction, Cu-N center doped graphene oxide grafted with hollow periodic mesoporous organosilica nanocontainer (MBT@HPMO/Cu-GO) is synthesized via facile adsorption-pyrolysis strategy. Herein, introduced MBT@HPMO/Cu-GO is to simultaneously endow coatings with corrosive media shielding, active oxygen consumption and stimuli-responsive functions, thus “three birds with one stone”. The target catalyst exhibits excellent oxygen depletion performance (half-wave potential of 0.85 V) and is uniformly dispersed in the coating to construct steric hindrance against corrosive media. This dual effect allows composite coating to maintain the excellent anticorrosion performance over 60 days under oxygen environment. In addition, MBT@HPMO/Cu-GO can release inhibitor at corrosion sites in response to environment change when coating is damaged, so as to restore the protective ability of coating, with impedance increased from 2.4 × 107 Ω·cm2 to 1.5 × 108 Ω·cm2. Such multifunctional coating exploration overcomes the protective limitation of current self-healing coatings and sheds light on the design of intelligent long-term anticorrosion coatings.