Corrosion of metals is a serious environmental problem. Most of the corrosion inhibitors are synthetic chemicals that are hazardous to environments and expensive. Today, there has been an increasing search for green corrosion inhibitors, due to the toxicity of some inhibitors. Green corrosion inhibitors are biodegradable and free of heavy metals or other toxic compounds. There is an intensive effort underway to develop new plant origin corrosion inhibitors for metal subjected to various environmental conditions. Salts of rare earth elements can be also used as inorganic alternative nontoxic corrosion inhibitors. Sol-gel coatings can be recommended as green protective films for metal corrosion. The origin of sol-gel process, its advantages and limitations, and the type of coating method are presented in this chapter, as well as a brief summary of recent literature concerning the use of hybrid inorganic-organic sol-gel and nanostructured sol-gel protective coatings for metal corrosion in different media.
Part of the book: Corrosion Inhibitors, Principles and Recent Applications