## 2 Utilization of Various Nano-Modified Coatings for Corrosion Mitigation
In the industrial sector, spray-coating methods are frequently employed to apply organic binders and lacquers onto erratically structured glass, fabrics, wood, and metals. Among the most popular spray-coating methods is thermal spraying. The coating substance is warmed or liquefied and sprayed over the substrate during this procedure. Typically, chemical or electrical techniques are used to warm the coating substance. In comparison to other traditional techniques such as PVD and CVD, thermal spraying allows for the faster coating of surfaces with vast surface regions. Increased toughness, reduced permeability, and improved adherence are all benefits of cold-sprayed coatings [67; 68]. In this approach, a solvent with a chemically active constituent is used as aprecursor, accompanied by polycondensation and hydrolysis to create a sol unit. A coating is created by drying and heating a gel that is created by gently polymerizing a sol. Coatings made using the sol-gel technique have consistent physical and chemical properties. The sol-gel technique's ability to form a coating relies on a number of variables, including the catalyst's chemistry, the primary substance used to make the sol, heating, density, pH, etc. The sol-gel method could be utilized to create coatings that are wear-resistant. Sol-gel technology has also been utilized to create coatings for nanocomposite materials that are microns thick. The electrodeposition process includes depositing a metal or alloy coating substance along a conductive substratum that is submerged in an electrolyte with a salt of the metal that is to be covered utilizing an electric current (electrolysis). By altering empirical variables including the electric voltage, current density, exposure duration, and content of the plating medium, the content, geometry, and smoothness of the coating can be changed. Utilizing a high-energy laser to shred granular or wire feedstock's intended substance over the substratum, laser cladding is a technique for producing nanostructured coatings. Laser procedure variables like power input and scan rate significantly impact coating integrity. When contrasted to alternative technologies, laser cladding provides benefits including excellent cooling rates, minimal dispersion rates, and flexibility of mechanization. This technique could be utilized to layer coatings using a variety of powders. However, several drawbacks of the laser cladding method include non-uniform content, poor metallurgical integrity, and coating defects. Additionally, a range of criteria, such as the needed nanoparticle size, surface properties, and levels of biodegradability, biocompatibility, and cytotoxicity, influence the choice of matrix materials. By incorporating organic or inorganic NPs, it is possible to change the physical characteristics of coating matrices [69; 70; 71]. For instance, a nanocomposite or nanocoating comprising some inorganic NPs could prevent cracks from forming and spreading, fill porosities, and begin fracture bridging, deflection, and bowing. Therefore, a competent design of a nanocomposite might create the composite material system with the desired physical characteristics by taking into account the intricate interplay between the matrix, interface, and NPs. In this section, the various types of nano-modified coatings including self-healing-based nanocoating, natural source-based nanocoating, metal/metallic oxide-incorporated nanocoating, and carbon allotrope-based nanocoating have been discussed with their excellent corrosion-inhibition efficiency and fabrication procedures for various nanocoatings.