Use of Time Domain Nuclear Magnetic Resonance Relaxometry to Monitor the Effect of Magnetic Field on the Copper Corrosion Rate in Real Time

Titelangaben

Mitre, Cirlei Igreja Nascimento ; Ferreira Gomes Lobo, Bruna ; Paris, Elaine ; Lobo, Carlos M. S. ; Roth, Christina ; Colnago, Luiz Alberto:
Use of Time Domain Nuclear Magnetic Resonance Relaxometry to Monitor the Effect of Magnetic Field on the Copper Corrosion Rate in Real Time.
In: Magnetochemistry. Bd. 8 (2022) Heft 4 . - 40.
ISSN 2312-7481
DOI: https://doi.org/10.3390/magnetochemistry8040040

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Abstract

The corrosion of metals is a major problem of modern societies, demanding new technologies and studies to understand and minimize it. Here we evaluated the effect of a magnetic field (B) on the corrosion of copper in aqueous HCl solution under open circuit potential. The corrosion product, Cu²⁺, is a paramagnetic ion and its concentration in the solution was determined in real time in the corrosion cell by time-domain NMR relaxometry. The results show that the magnetic field (B = 0.23 T) of the time-domain NMR instrument reduces the corrosion rate by almost 50, in comparison to when the corrosion reaction is performed in the absence of B. Atomic force microscopy and X-ray diffraction results of the analysis of the corroded surfaces reveal a detectable CuCl phase and an altered morphology when B is present. The protective effect of B was explained by magnetic forces that maintain the Cu²⁺ in the solution/metal interface for a longer time, hindering the arrival of the new corrosive agents, and leading to the formation of a CuCl phase, which may contribute to the rougher surface. The time-domain NMR method proved to be useful to study the effect of B in the corrosion of other metals or other corrosive liquid media when the reactions produce or consume paramagnetic ions.