The effect of carbon nanotubes loaded with 2-mercaptobenzothiazole in epoxy-based coatings

Currently, anticorrosive coatings find a large number of applications and can be effectively used for corrosion protection of many corrosion-prone metals like aluminum, iron, etc. Nanocontainers have the ability to encapsulate large amounts of guest molecules within their core, and releasing them in a controlled way can aid in providing self-healing abilities to the coating, thus providing active protection. In the present study, a novel approach of synthesis of nanocontainers using carbon nanotubes (CNTs) and corrosion inhibitor 2-mercaptobenzothiazole has been discussed with their applications in corrosion protection of mild steel (MS). It is a three-step procedure involving layer-by-layer deposition of the CNT, inhibitor, and polyelectrolytes, which thus provides enhanced corrosion protection when coated on MS plates. The thickness of the layer, surface charge, and functional groups present on each layer were identified using various analytic techniques such as particle size distribution, zeta potential, and FTIR analysis. X-ray diffractograms analyses of CNT and modified CNT were performed to evaluate their crystallographic properties. The morphological and particle size clearly indicate the development of a nanocontainer. The corrosion rate analysis of nanocontainer-epoxy coatings on MS panel has been performed by means of salt spray and DC polarization measurements. The corrosion resistance was measured after the immersion of the coated samples in alkali solution.