An EIS study of the conservation treatment of the bronze sphinxes at the Museo Arqueológico Nacional (Madrid)

Barat, Blanca Ramírez; Crespo, Ana; Garcia, Emma; Díaz, Soledad González; Cano, E.

doi:10.1016/j.culher.2016.10.010

Cited by 19 publications

(11 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ramirez Barat and Cano [50] chose the bronze sphinx at the facade of the Spanish National Archaeological Museum (MAN) in Madrid to perform a comparative evaluation (i.e., an analytical validation) between the new portable G-PE-based cell, equipped with the solid electrolytes, and the laboratory-cast bronze coupon samples. The two bronze sphinxes were previously protected with Incralac [51] and the resulting EIS measurements were comparable to data collected in the case of the bronze coupon samples. The |Z| parameter (mainly considered to be low-frequency-range values as a total evaluation of the corrosion resistance [52]) is useful to establish whether a metallic layer is working better than other coatings.…”

Section: Electrochemical Impedance Spectroscopy In Chmentioning

confidence: 82%

Smart Electrochemical Portable Tools for Cultural Heritage Analysis: A Review

Valentini

2019

Sensors

View full text Add to dashboard Cite

Protecting Cultural Heritage (CH) from corrosion and other environmental damages, mainly involving metallic or organic layers contained in artwork, represents a major challenge for conservation scientists. Electrochemical techniques provide useful information about the deterioration effects of metallic coatings and organic layers. Recently, Electrochemical Impedance Spectroscopy (EIS) has been successfully applied in the study of metallic corrosion. However, EIS has not succeeded in becoming a routine technique, due to problems regarding both instrumental apparatus (which is not ideal for in situ analysis, especially with previous cell configurations), and the difficulty with data processing. At the same time, new portable electrochemical sensors, immunosensors, and biosensors have successfully made a scientific impact, mainly with in situ diagnosis of organic components contained in CH objects. For this purpose, this review presents two sections: the first describes the analytical optimization of impedance electrochemical cell geometries that are suitable for in situ metal-coating investigation; the second reports on the assembly of small electrochemical sensors, immunosensors, and biosensors, which useful for in situ organic layer characterization. This overview summarizes the state of the art regarding the application of electrochemical techniques and small electrochemical devices as alternative tools for the understanding of CH.

show abstract

Section: Electrochemical Impedance Spectroscopy In Chmentioning

confidence: 82%

Smart Electrochemical Portable Tools for Cultural Heritage Analysis: A Review

Valentini

2019

Sensors

View full text Add to dashboard Cite

show abstract

“…Higher impedance values were observed only on surfaces with remains of protective coating. Ramirez et al [ 45 ] used agar-based electrolyte for studies of bronze sphinxes, wherein they examined two surface areas, one with dark patina with impedance moduls around 10–20 kΩ·cm 2 and another with green patina layer exhibiting impedance modulus around 30–50 kΩ·cm 2 . In our study, spectrum obtained for NI1 exhibited the highest impedance modulus (0.14 M Ω·cm 2 ) compared to other two surface areas.…”

Section: Resultsmentioning

confidence: 99%

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

et al. 2021

View full text Add to dashboard Cite

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.

show abstract

“… Bode plot (right) of the sphinx at the main façade of the National Archaeological Museum in Madrid (pictured left). The Sphinxes, casted in 1894, were restored and protected with Incralac® and wax a couple of years before ,…”

Section: Resultsmentioning

confidence: 99%

“…In previous studies agar showed a certain decrease in impedance values if compared to the liquid electrolyte, which was attributed to some anodic depolarizing effect in bronze, slightly increasing the measured corrosion rate if compared to a traditional liquid electrolyte. Though this effect can be minimized using low agar concentrations and it is not a problem for comparative studies,, further improvements of the measuring system were considered.…”

Section: Introductionmentioning

confidence: 99%

Agar versus Agarose Gelled Electrolyte for In Situ Corrosion Studies on Metallic Cultural Heritage

Barat

Cano

2019

ChemElectroChem

Self Cite

View full text Add to dashboard Cite

The use of gelled electrolytes has revealed an interesting solution for in situ electrochemical measures on cultural heritage, where liquid electrolytes cannot be easily handled. After developing an agar gelled electrolyte cell, other gelling agents such as agarose are being considered to improve it. In this work, the performance of agarose gels in different concentrations has been studied and compared to agar and a liquid electrolyte. Measurements have been done on patinated quaternary bronze and weathering steel, as representative materials of outdoor monuments. Agarose gels have been validated for in situ corrosion studies on bronze and weathering steel sculptures.

show abstract

An EIS study of the conservation treatment of the bronze sphinxes at the Museo Arqueológico Nacional (Madrid)

Cited by 19 publications

References 25 publications

Smart Electrochemical Portable Tools for Cultural Heritage Analysis: A Review

Smart Electrochemical Portable Tools for Cultural Heritage Analysis: A Review

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

Agar versus Agarose Gelled Electrolyte for In Situ Corrosion Studies on Metallic Cultural Heritage

Contact Info

Product

Resources

About