A review on self-healing coatings based on micro/nanocapsules

Polymer coating systems are classically applied on a metal surface to provide a dense barrier against the corrosive species. Coatings are susceptible to damage in the form of cracks, which form deep within the structure where detection is difficult and repair is almost impossible. Major advances for automatic repairing of defects have been made in the present decade within the field of self-healing polymeric materials. One of the most significant types of smart coatings is self-healing coating, which has the ability to release encapsulated active agents in a controlled way. They can be employed to develop a new family of smart multifunctional coatings. Incorporating micro/nanocapsules in coating matrix provides release of repairing agent rapidly after triggering due to crack propagation in coatings and gifts the self-healing to the coatings. This review covers the effective parameters in synthesis of micro/nanocapsules, several approaches to fabricate self-healing coatings based on these capsules and disadvantages of embedding them in coatings matrix. Current comprehensive review also provides all the knowledge of self-healing coatings based on micro/nanocapsules to whom that are concerned with coatings and corrosion prevention.