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Copper corrosion in soils contaminated with high concentrations of chlorides
Niculita, E.; Ornelas, I.; Capelo, Sofia; Fonseca, I.T.E.The influence of the soil composition on the corrosion resistance of buried metallic structures and the nature of the corrosion products formed are of great importance in many industrial applications, as well as in archaeological studies of metallic finds. Modifications in the soils characteristics can result from agricultural activity, such as fertilization, chemicals accidentally spilled into the soil (acids ...
Linear sweep voltammetry: a cheap and powerful technique for the identification...
Capelo, Sofia; Menino Homem, P.; Cavalheiro, J.; Fonseca, I.T. E.The potentialities of linear sweep voltammetry (LSV) for the characterization of the tarnish layer formed on pure and sterling silver samples exposed in the chapel and in the museum, at the Cathedral of Porto, in Portugal, are well demonstrated in this study. The technique allows the identification of the constituents of the thin tarnishing layers and also its relative abundance. A much more complex composition...
Controlling pollution effects on metallic cultural heritage using linear sweep ...
Capelo, Sofia; Menino Homem, P.; Cavalheiro, J.; Fonseca, I. T. E.This work demonstrates the potentialities of the linear sweep voltammetry (LSV) for monitoring the composition of the tarnishing layers formed on silver and on the silver-copper alloys exposed to atmospheres contaminated with pollutants, such as H2S and chloride ions, among others. A collection of silver and sterling silver coupons exposed during periods of 1 and 12 months, at the Holy Altar of the Chapel and a...
Monitoring Corrosion Products on Metal Artefacts by Linear Sweep Voltammetry (LSV)
Capelo, Sofia; Homem, P.; Cavalheiro, J.; Fonseca, I.T.E.Metallic surfaces are highly sensitive to their surroundings, and prone to react with airborne pollutants to form complex layers. Electrochemical techniques have the possibility of simultaneously identifying different electroactive compounds [1]. The high sensitivity of Linear Sweep Voltammetry (LSV) allows the detection of extremely thin surface films before they became visible. LSV leads to reduction peaks, w...
Corrosion of brass in a natural and artificial seawater under anaerobic conditions
Bastos, M.C.; Mendonça, M.H.; Neto, M.M.M.; Rocha, M.M.G.S.; Proença, L.; Fonseca, I.T.E.The corrosion of brass in deoxygenated nonbuffered and buffered artificial and natural seawater was studied. The weight gains and the average corrosion rates of brass samples, immersed in both media during periods of 1 week, 1 and 3 months, were determined. The morphology of the corroded surfaces, with and without the corrosion products, was analyzed by visual observation and scanning electron microscopy (SEM)....
Electrochemical studies on the corrosion of brass in seawater under anaerobic c...
Bastos, M.C.; Proença, L.F.A.; Neto, M.M.M.; Fonseca, I.T.E.This paper reports an electrochemical study on the corrosion of brass in deoxygenated nonbuffered and buffered natural and artificial seawater solutions under anaerobic conditions. Cyclic voltammograms of brass and copper in natural seawater (NSW) and artificial seawater (ASW) were obtained in the passive and transpassive potential regions. The corrosion resistance of brass in natural and artificial seawater wa...
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