### Nanomaterials/Nano-Modified Coatings as Corrosion Inhibitors
The optimal variables to generate greater processing outputs, better encapsulating rates, and superior releasing qualities were determined from the various process variables examined to be an intake pumping frequency of 2.5 mL/min, a temperature of 170 \({}^{\circ}\)C, and a drying air-flow frequency of 440 L/h. Furthermore, in their demonstration, [PERSON] et al. [44] utilized a biodegradable polyol based on cardanol to generate nanocomposite polyurethane (PU) coverings. In order to create nanocomposite anticorrosive coverings, magnetic hydroxyapatite NPs (MHAP) were distributed 1-5% in PU compositions. As measured using submerged and electrochemical techniques, MHAP's anticorrosive efficacy improved with increasing intensity. Figure 5 shows the FT-IR spectra of MHAP NPs. The -OH bending vibration was responsible for the maximum absorption at 3570 cm\({}^{-1}\). While the phosphate moiety displayed absorption at 630 and 1035 cm\({}^{-1}\), the stretching vibrations of carbonyl were recorded at 871 and 1458 cm\({}^{-1}\). At 570 and 1619 cm\({}^{-1}\), the stretching oscillation of the Fe-O bond took place. This demonstrated that the formation of MHAP NPs was robust. Figure 4: SEM scans of CMC.BTA microspheres attained by the technique of spray-drying in distinctive empirical situations: (**a**) 440 L/h and 170 \({}^{\circ}\)C; (**b**) 600 L/h and 170 \({}^{\circ}\)C; (**c**) 440 L/h and 180 \({}^{\circ}\)C; (**d**) 600 L/h and 180 \({}^{\circ}\)C; (**e**) 440 L/h and 190 \({}^{\circ}\)C; and (**f**) 600 L/h and 190 \({}^{\circ}\)C. Reprinted with permission from Ref. [18]. MDPI (2022). In terms of elasticity, cross-cut adherence, gloss, pencil stiffness, and chemical stability, the nanocomposite PU coverings demonstrated excellent coating characteristics. The coatings were further examined using SEM and TGA for surface morphology and thermal characteristics. The introduction of MHAP enhanced the hydrophobic properties of PU coatings, and a maximum result (105) was seen at a 3% dosage. The created coatings demonstrated their hydrophobicity with outstanding anticorrosive efficacy. Using low-carbon steel (CS) surfaces, [PERSON] et al. [45] developed Tin (Sn) matrices nanocomposite coverings including NiO and ZnO NPs, both separately and in combination. Investigating the impact of NPs' reinforcements upon the microstructural geometry and density of Sn coverings, altering the interfacial barrier between the substrate and coating, and examining the corrosion protection of the low-CS sample were the main objectives. In this study, NiO and ZnO NPs of different types were employed. The thermal degradation of nickel acetate Ni((CH\({}_{3}\)COO)24H\({}_{2}\)O) at 500 \({}^{\circ}\)C for 2 h in a muffle furnace produced the nano-sized NiO powder. With the use of a ball milling method for 1 h at 600 rpm, the resulting NiO powder's size was brought down to the nanoscale. The well-known up-down method was used to synthesize ZnO on the nanoscale. In short, 98% pristine ZnO powder (Advic) was utilized as the precursor substance, and SS balls were utilized to grind the content for 24 h at 600 rpm while it was at atmospheric pressure and ambient temperature. The proportion of balls to powder was 10:1. Following grinding, a very granular nanopowder containing several nanometers was produced. Sn-coated low-CS surface and Sn-nanocomposite coverings comprising NiO and ZnO NPs were shown in the substrate's cross-sectional nanostructure, which was responsible for the corrosion mitigation process. In the inter-metallic layering of Sn-composite coverings, Figure 6 depicts the shape of the protective coating, which is crucial to its production. Moreover, the inclusion of reinforced NP elements had a significant impact on the density of the interface and inter-metallic coatings of Sn-composite-coated films. Sn was the only coating applied to the low-CS surface, and it is an erratic, extremely thin coating having an extremely modest thickness (Figure 6a).