The synergic effect of microcapsules and titanium nanoparticles on the self-healing and self-lubricating epoxy coatings: A dual smart application

In the present study, the multi-functional smart epoxy coatings were fabricated by incorporating the 15 wt.% microcapsules containing the linseed oil and various percentage of nano-TiO2 (4, 8, 12 and 16 wt.%). The self healing and self-lubricating abilities of these nanocomposite coatings were investigated by corrosion and wear tests. The obtained results showed that the smart coating containing the 16 wt.% nano-TiO2 had the best function in the corrosion media, due to healing a scratch in form of layer by layer. By using the microscopically analysis, it was found that the linseed oil acted as lubricant agent in the wear test. Adding 4 wt.% nano-TiO2 had the negative effect on the anti-wear properties, due to forming the nanocomposite debris. However, by increasing the percentage of nano-TiO2 up to 12 wt.%, the anti-wear properties had the enhancing trend. Improving the mechanical function of coatings, forming the nano-TiO2/linseed oil self-suspense and trapping the debris by capsule containers were the characterized mechanisms for improving the anti-wear properties. It was also realized that the formation of nano-TiO2/epoxy skin on the surface of microcapsules and agglomeration of nanoparticles had the negative effect on the wear properties of smart coatings.

Automated summary

The study found that the smart coating containing 16% nano-TiO2 exhibited the best performance in corrosion media, with the ability to heal scratches layer by layer. Additionally, adding 12% nano-TiO2 improved the anti-wear properties. However, the formation of nano-TiO2/epoxy skin and nanoparticle agglomeration on the surface may have negative effects on the wear properties of smart coatings.