Smart self-healing polymer coatings: Mechanical damage repair and corrosion prevention

Abstract

Self-healing polymers are special category of smart materials where its properties change in response to an environmental stimulus. These materials have the capability to repair themselves when they are damaged without the need for any external intervention. In the first part, the principles and fundamentals of various types of smart coatings, materials, design, and processing methods are described. In the second part, various strategies to heal the mechanical damage have been targeted. Employing intrinsic self-healing materials with inherent bonding reversibility of the polymer matrix is the most important strategy which has been reviewed in this section. In the third part, the microencapsulation approaches to self-healing polymer development will be reviewed. This section will characterize polymer coatings that are classified as self-healing, based upon self-healing agents that are microencapsulated, active inhibitors loaded into nanoparticles, as well as nanocontainers and polymers that are constructed by the layer-by-layer (LbL) method. Finally, corrosion inhibitors that rely upon controlling micro- and nanoreservoirs release for the intercalation or encapsulation will be also reviewed. In this regard, application of layered double hydroxides (LDHs), porous nanoparticles, hollow spheres, zeolites, bentonite, and montmorillonite with active corrosion inhibitors are to be explained as well.