engleski

Protection of bronze works of art from the effects of polluted urban atmospheres

Bronze has been widely used in construction of sculptures and other works of art for ages. When bronze is exposed to atmosphere on its surface a layer of corrosion products called patina is formed. This layer is usually blue or green and decorates the piece of art, but also protects it. Due to increased environmental pollution, bronze objects and the patina on their surface dissolve with time. In order to preserve cultural heritage in these conditions it is necessary to apply additional protection from corrosion. The aim of this research is to experimentally determine the impact of polluted urban atmosphere on the corrosion of bronze sculptures, and to explore the possibility of applying a corrosion inhibitor to protect them. A polluted urban atmosphere in the experiments is simulated with a Na2SO4 + NaHCO3 solution at pH = 3 and 5. The investigated inhibitor is 2- mercaptobenzimidazole. Electrochemical methods that were used for testing the corrosion process are: Tafel extrapolation method, linear polarization method and electrochemical impedance spectroscopy. The experiments showed that the investigated inhibitor protects bronze and its patina in the conditions of polluted urban atmospheres.

Corrosion inhibitor; electrochemical impedance spectroscopy; acid rain

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