The chief aim of this book is not only to explore the occurrence of corrosion in materials but also to describe the methods of corrosion by composite barrier formation. This book is an embodiment of the long felt need and urge of the students in the field of corrosion science and engineering. The materials are used in composite barrier formation to works as repeller in ambient environments. This book is covered the methods of formation of composite barrier and their surface adsorption parameters. This book is mainly divided into six chapters and their contents are expressed as chemistry of corrosion and corrosive environments in chapter-1, chemistry of composite barrier formation in chapter-2, chemistry of corrosion rate determination in chapter-3, chemistry of synthesis of organic compounds for nanocoating in chapter-4, chemistry of nanocoating, filler and electrospray materials in corrosion protection in chapter-5 and mechanism of corrosion mitigation in chapter-6. This book is very informative about various types of corrosive pollutants, effluents, flues, acids, alkalis, salts, particulates and biowastes which create hostile environments for materials.