Corrosion inhibitors are largely used to prevent chloride-induced corrosion in reinforced concrete structures. The interaction mechanisms with the passive film present on steel still requires deeper understanding. In a previous work based on molecular mechanics and molecular dynamics methods [M. V. Diamanti, E.A. Pérez Rosales, G. Raffaini, F. Ganazzoli, A. Brenna, M. Pedeferri, M. Ormellese, Corrosion Science, 2015] we considered organic inhibitors adsorbed on gamma-FeOOH, comparing theoretical results with experimental data. Here we considered the initial interaction with the inhibitor film and chlorides. In particular, the adsorbed tartrate monolayer show the best behavior thanks to the repulsions by the COO- groups exposed to chlorides, more distant from the gamma-FeOOH surface, whereas the dimethylethanolamine film doesn’t have the same repulsion. Based on these observations, molecular mechanics and molecular dynamics confirm to be an additional, powerful tool to understand the behaviour of inhibitors in the presence of a bare or passivated metallic surface, as well as to predict their potential efficiency in inhibiting steel corrosion in the chosen environmental conditions.

Molecular modelling of organic inhibitors in concrete

G. Raffaini;F. Ganazzoli;M. Ormellese
2018-01-01

Abstract

Corrosion inhibitors are largely used to prevent chloride-induced corrosion in reinforced concrete structures. The interaction mechanisms with the passive film present on steel still requires deeper understanding. In a previous work based on molecular mechanics and molecular dynamics methods [M. V. Diamanti, E.A. Pérez Rosales, G. Raffaini, F. Ganazzoli, A. Brenna, M. Pedeferri, M. Ormellese, Corrosion Science, 2015] we considered organic inhibitors adsorbed on gamma-FeOOH, comparing theoretical results with experimental data. Here we considered the initial interaction with the inhibitor film and chlorides. In particular, the adsorbed tartrate monolayer show the best behavior thanks to the repulsions by the COO- groups exposed to chlorides, more distant from the gamma-FeOOH surface, whereas the dimethylethanolamine film doesn’t have the same repulsion. Based on these observations, molecular mechanics and molecular dynamics confirm to be an additional, powerful tool to understand the behaviour of inhibitors in the presence of a bare or passivated metallic surface, as well as to predict their potential efficiency in inhibiting steel corrosion in the chosen environmental conditions.
2018
Corrosion, Mechanism, Molecular Dynamics Simulation, Passive film
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/1065101
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