## 2 Utilization of Various Nano-Modified Coatings for Corrosion Mitigation
### Self-Healing-Based Nano-Modified Coating
The generated covering (PU-DA-d@CeNPs5) showed an impedance value at 0.01 Hz of 1.29 \(\times\) 10\({}^{-9}\)\(\Omega\) cm\({}^{2}\), outstanding mechanical properties (38.89 \(\pm\) 0.52 MPa), and noteworthy adhesive capabilities (12 MPa). Following 100 days of constant soaking, the impedance factor at 0.01 Hz was greater than 107 \(\Omega\) cm\({}^{2}\). Dopamine's capacity for photothermal transformation also permitted the covering to self-heal in a matter of seconds when exposed to near-infrared light. Prior to and following self-healing, the coating's tribological and mechanical resistance was essentially unaltered. This research offered a practical method for creating an anti-corrosion polyurethane covering featuring superior mechanical properties and a significant degree of self-healing. Figure 8: Impedance curves for C-steel in acidic media: (**A**) Nyquist with the exclusion and inclusion of various dosages of PAC; (**B**) Nyquist with the exclusion and inclusion of 250 ppm of several nanocomposite inhibitors; and (**C**) Bode and (**D**) phase curve illustration with the exclusion and inclusion of various dosage of PAC at 50 \({}^{\circ}\)C. Reprinted with permission from Ref. [74]. MDPI (2021). [PERSON] et al. [78] fabricated self-healing covering of epoxy resin integrated with core-shell NPs of organic polysulfide@urea-formaldehyde resin as self-healing agents and PANI/ZnO nanocomposites. The self-healing efficacy and corrosion mitigation property of the scratched covering on the anodized 2024-T3 Al alloy substrates in 3.5% brine medium at 65 \({}^{\circ}\)C were examined. In this work, 0.045 g of ZnO NPs and 4.5 g (48 mmol) of aniline were combined in 200 mL of distilled water to create PANI/ZnO nanocomposites. To obtain a homogeneous suspension of ZnO, the liquid was aggressively agitated with magnetic stirring in an ice water bath for 4 h. After that, in the ZnO suspension, 1 g (3 mmol) of DBSA was vigorously agitated for 2 h at 0 \({}^{\circ}\)C. The PANI/ZnO nanocomposite initially appeared as a white precipitate, which was subsequently strained and repeatedly rinsed with methanol and distilled water. After 12 h of drying in a vacuum oven at 50 \({}^{\circ}\)C, the result yielded 3.49 g of PANI/ZnO nanocomposite (PZ1). Core-shell NPs comprising a healing agent were disseminated in epoxy resin and TEPA matrices together with the manufactured nanocomposite in proportions of 0, 5, 7.5, and 10 weight percent to create coating material. As revealed from the Bode graphs, in the scenario of a scratched covering without core-shell NPs (EPZ1), the coating resilience began to deteriorate immediately following 96 h of exposure to corrosive fluids. On the other hand, the Bode graphs of the coatings (EPZ1C5, EPZ1C7.5, and EPZ1C10) with different quantities of core-shell NPs reveal that, for all of the coatings, the resistance (Rc) was decreased upon scratching owing to the penetration of electrolytes via the scratches. Furthermore, the decrease in coating resistance over time was not as pronounced as it was for coatings without additional core-shell NPs, showing that these particulates had a protective impact against corrosion. The permeable oxide layer on anodized substrates improved the covering efficiency. The improvement in corrosion resistance of coatings was caused by the addition of 1.54 wt% of PANI/ZnO nanocomposite. Eventually, the EPZ1 coating on anodized aluminum that included 7.5 wt% core-shell NPs exhibited the best self-healing behavior.