Stimuli-responsive self-healing anticorrosion coatings: from single triggering behavior to synergetic multiple protections

As a notorious and ubiquitous destructive phenomenon, metal corrosion can cause huge economic losses, infrastructure failures, and even industrial disasters. Tremendous efforts have been dedicated to intelligent self-healing coatings for corrosion inhibition at damaged sites, targeting for enhanced longevity, extensive adaptability of metallic materials. Anticorrosion coating performing self-healing activities, by either healing coating defects or forming protective layer on corrosive parts, is quite attractive in metal-relevant applications. In this review, we mainly focus on stimuli-feedback anticorrosion coatings (SFACs), based on different triggering mechanisms to initiate self-healing behaviors. Stimuli-responsive smart systems, from single stimulus-response to synergetic multistimuli-response, act as a core concept both in controllable healing agent diffusion and increased availability of payloads for corroded area. Multifunctional stimuli-responsive self-healing coatings integrating with non-wettable property are also explored, which provide synergistic and diversified metal protections that are hard to actualize with a single action. Not only research progress of SFACs over the past few decades is reviewed in this article, but also perspectives on future development of this field are presented.