Corrosion: Favoured, Yet Undesirable - Its Kinetics and Thermodynamics

This chapter describes the fundamentals of metal corrosion in relation to thermodynamics and kinetics. The chapter is so titled, because corrosion of metal is thermodynamically favourable. Moreover, it impacts negatively on economy and safety. Industries expend a substantial percentage of their budgets on corrosion control, and lose revenue due to corrosion damage. Effects of corrosion on industrial and public infrastructure cannot be overemphasized. Several accidents in the transportation and recreational industries have been linked to corrosion of metallic parts of respective gadgets. Some of these accidents are utterly catastrophic and fatal. Therefore, corrosion, albeit its thermodynamic favouability, is not desired by man. Metals corrode as a way of minimizing energy contents. Active metals are more stable in combined forms such as oxides, sulphides, and hydroxides, even though these forms are less useful to man. It appears the “price” to pay for extracting the pure forms of these metals from their ores is corrosion. This chapter presents fundamentals of thermodynamics and kinetics of metal corrosion, with emphasis on aqueous medium. It promises to serve as an introductory chapter for corrosion science students and as a concise material for tutors.

Inhibition of steel corrosion by some Schiff and Mannich bases: a theoretical evaluation

There is no doubt that the value and importance of using computational methods in corrosion science are becoming gradually recognized. Drilling deeper into the thought that certain molecular electronic descriptors such as ionization potential, electron affinity, HOMO–LUMO gap and dipole moment matter, because they present a unique solution to comprehend the inhibition properties of corrosion inhibitors, leads us to a further quandary. The reliability of such parameters is the subject of acrimonious debate, and thus, the present study is an extension of this attempt to contemplate earlier experimental results reported for some Schiff and Mannich bases as corrosion inhibitors for steel in neutral aqueous solutions by using density functional theory calculations. Due to the sources of uncertainties like the structure of the molecular model, the description of environmental efforts and errors related to the nature of quantum chemical methods, it was inferred that no coherent picture could be emerged about the corrosion inhibition properties of the studied compounds through calculated descriptors.

IN MEMORIAM: Jose Antonio Gonzalez (1937–2021)

Jose Antonio Gonzalez, 83, died May 31, 2021 in Madrid, Spain. He was an esteemed Professor in corrosion science and engineering at the National Center for Metallurgical Research (CENIM-CSIC) for 45 years. Jose Antonio was pivotal in developing electrochemical methods for the study of corrosion of steel in concrete, and his continuous dedication and passion for research was undeniable. A generous mentor, Jose Antonio helped countless students become scientists, researchers, and engineers from all around the globe.