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. Six mainly stimuli-responsive anticorrosion systems are systematically introduced, and responsive smart systems in combination with non-wettable surface are also summarized. According to different action mechanisms, corrosion protection can be classified into two parts: metal substrate protection and damaged coating recovery. • Stimuli-feedback self-healing anticorrosion coatings could inhibit the spontaneous release of payloads by introducing responsive control elements. • Anticorrosion mechanisms dependent on different self-healing actions were summarized. • Six mainly triggering mechanisms that initiate self-healing turn-on anticorrosion behaviors were systemically introduced. • Multifunctional responsive systems synergetic with non-wettable surface were detailedly presented.