ZnO, Zn(OH)2, Zn5(OH)8Cl2·H2O, ZnCO3, and Zn5(CO3)2(OH)6 synthetic powders were prepared by chemical or solid-state method. Their crystalline phase structure, thermal behavior, and morphology were examined. Characteristic infrared absorbance bands were estimated by means of FT-IR ATR spectroscopy. X-ray photoelectron spectroscopy (XPS) allowed to calculate the modified Auger parameters (α ′) thereof to 2010.2, 2009.3, 2009.4, 2009.7, and 2009.8 eV, respectively for ZnO, Zn(OH)2, Zn5(OH)8Cl2·H2O, ZnCO3, and Zn5(CO3)2(OH)6. Finally, comparison of surface composition may be crucial to evaluation of the unknown experimental spectra of corrosion products formed on the surface of zinc alloy coatings exposed in NaCl solution.
Nonmetallic (based on polymers or oxides) and metallic protective coatings are used to protect metal products against the harmful action of the corrosion environment. In recent years, self-healing coatings have been the subject of increasing interest. The ability of such coatings to self-repair local damage caused by external factors is a major factor contributing to their attractiveness. Polymer layers, silica-organic layers, conversion layers, metallic layers and ceramic layers, to mention but a few, are used as self-healing coatings. This paper presents the main kinds of self-healing coatings and explains their self-healing mechanisms.