An Electrochemical and Spectroscopic Study of Surfaces on Bronze Sculptures Exposed to Urban Environment

Materials

Neven Peko¹  Tadeja Kosec²  Dajana Mikić³  Helena Otmačić Ćurković³ 

[1] Conservation-Restoration Workshop, Sisak City Museum, HR 44000 Sisak, Croatia;Laboratory for Metals, Corrosion and Anticorrosion Protection, Slovenian National Building and Civil Engineering Institute, SI 1000 Ljubljana, Slovenia;Research Laboratory for Corrosion Engineering and Surface Protection, Faculty of Chemical Engineering and Technology, University of Zagreb, HR 10000 Zagreb, Croatia;

关键词: bronze;    patina;    spectroscopy;    electrochemical behavior;   

DOI  :  10.3390/ma14082063

来源: DOAJ

【 摘 要 】

Polluted urban environment enhances dissolution of patina and underlying bronze material of recent and historical bronze sculptures exposed outdoors. In this work, two bronze statues, situated in one of the most polluted Croatian cities, were examined in order to characterize composition of patina and its electrochemical stability. The composition of patina on several positions on each sculpture was determined by EDS, Raman spectroscopy, and FTIR measurements. Electrochemical impedance spectroscopy measurements were conducted in order to evaluate the corrosion stability of both patina and underlying bronze. Results obtained in this work show that the two examined bronze sculptures were covered with patina layer that was mainly composed of copper sulfides and sulphates, which is in accordance with the high concentrations of H₂S and SO₂ in the atmosphere. However, the variations in the appearance of FTIR and Raman spectra revealed that the amount of each species differed from spot to spot, as well as the fact that other compounds, such as carbonates, were present at some areas. This difference in patina composition was reflected in electrochemical behavior as observed by electrochemical impedance spectroscopy.

【 授权许可】

Unknown