Abstract.
Organic corrosion inhibitors can be used to prevent chloride-induced corrosion in reinforced
concrete structures. In this theoretical study Molecular Mechanics (MM) and Molecular Dynamics
(MD) simulations are performed in order to better understand the interaction mechanisms with the
passive film present on steel [1], in particular considering γ-FeOOH surface as solid surface which
can be subject to chloride-induced corrosion process and the dimethylethanolamine (TETA) film
[2]. The MD simulations are a very useful tool because they describe at atomistic level both the
solid surface and organic inhibitors molecules in presence of chloride ions [2] and water molecules
[3]. Hydration of organic TETA inhibitor film in presence of chloride ions always accelerate the
corrosion process, as experimentally well known. In this theoretical work water molecules in fact
induce chloride ions to adsorb on γ-FeOOH surface more quickly and in greater numbers respect
with to the same simulations study without water molecules. This kind of organic film cannot
exhibit a good behavior to prevent the chloride-induced corrosion process not displaying the so
important repulsion to chloride ions. The hydration accelerates the corrosion process. This
theoretical work permit to compare these results with another organic inhibitors films studied in
previous work [1] in order to prevent the corrosion.
References
[1] M.V. Diamanti, E. A. Pérez-Rosales, G. Raffaini, F. Ganazzoli, A. Brenna, M. Pedeferri, M.
Ormellese, Corrosion Science, 100, 231-241 (2015).
[2] G. Raffaini, M. Catauro, F. Ganazzoli, F. Bolzoni, M. Ormellese, Macromolecular Symposia,
395, Article Number: 2000231, pp. 1-3 (2021).
[3] G. Raffaini, F. Ganazzoli, J. of Biomed. Mat. Res. PART A, 92A, 1382-1391 (2006)