A review of advances in encapsulation processes and self-healing mechanisms for active corrosion protection.

Document Type : Review Article


1 Non-metallic Materials Research Group, Niroo Research Institute,, Tehran, Iran

2 Ph.D Student, Chemistry Department, Kashan university, P.O. Box: 87317-51167, Kashan, Iran

3 Assistant professor, Non-metallic Materials Research Group, Niroo Research Institute, P.O. Box 14665517, Tehran, Iran.


The use of organic coatings is the most common and cost-effective way to protect against corrosion and increase the useful life of many metal structures in corrosive environments. However, once the protective coating is damaged, the degradation processes spread rapidly. To achieve long-term coating performance in a corrosive environment, applied active protection along with self-healing defects is essential. In this review article, firstly, the characteristics of self-healing materials for anti-corrosion applications are stated, then the classification of the encapsulation process, which includes physical and chemical encapsulation, is discussed, and finally, a summary of recent works in the field of new multi-level protection systems is presented. It is based on the controlled release of anticorrosive species from smart micro- and nano-carriers in a polymer coating field. Also, this paper examines a self-healing approach that includes several damage prevention and repair mechanisms, including trapping of corrosive ions, corrosion inhibition, and water displacement from active defects. In the other part of the article, a review of the methods of evaluating the performance of self-healing coatings using electrochemical, surface and microscopic techniques is provided, and also suggestions for alternative electrochemical techniques for evaluating the self-healing coating are reviewed. Finally, in terms of modeling, computational research on self-healing materials is discussed.


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