A review of the characterization methods for self-healing assessment in polymeric coatings

Self-healing coatings have attracted a great deal of interest because of their ability to prevent or control the corrosion process, which is a serious challenge in almost all industries. Despite the fact that there are various methods for the evaluation of self-healing performance in coatings, there are still no standard and established methods for these assessments. This article reviewed the characterization methods for evaluating the self-healing behavior in polymeric coatings and highlighted the significant benefits and drawbacks of each method. Accordingly, all the methods assessing self-healing performance and self-healing efficiency in polymeric coatings that have been utilized in the most recent studies are described. These methods are classified into visualization and quantitative methods, and the equations for the determination of self-healing efficiency are introduced and the terms are defined. This review aims to provide a comprehensive overview of the characterization methods used in evaluating self-healing in polymeric coatings. Its objective is to pave the way for the development and industrial application of self-healing coatings by offering insights into the mechanisms of self-healing and identifying quantitative methods for its determination.