Reproducing bronze archaeological patinas through intentional burial: A comparison between short- and long-term interactions with soil
The reproduction of archaeological corrosion patinas is a key issue for the reliable validation of conservation materials before their use on cultural objects. In this study, bronze disks were intentionally buried for 15 years in the soil of the archaeological site of Tharros, both in laboratory and...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-09-01
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| Series: | Heliyon |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2405844023068342 |
| _version_ | 1797669865545269248 |
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| author | Francesca Boccaccini Cristina Riccucci Elena Messina Marianna Pascucci Ferdinando Bosi David Chelazzi Teresa Guaragnone Piero Baglioni Gabriel Maria Ingo Gabriella Di Carlo |
| author_facet | Francesca Boccaccini Cristina Riccucci Elena Messina Marianna Pascucci Ferdinando Bosi David Chelazzi Teresa Guaragnone Piero Baglioni Gabriel Maria Ingo Gabriella Di Carlo |
| author_sort | Francesca Boccaccini |
| collection | DOAJ |
| description | The reproduction of archaeological corrosion patinas is a key issue for the reliable validation of conservation materials before their use on cultural objects. In this study, bronze disks were intentionally buried for 15 years in the soil of the archaeological site of Tharros, both in laboratory and in situ, with the aim of reproducing corrosion patinas typical of archaeological artifacts to be used as representative surfaces for testing novel cleaning gels. The microstructural, microchemical and mineralogical features of the patinas were analyzed by a multianalytical approach, based on optical microscopy (OM), field emission scanning electron microscopy coupled with energy dispersive spectrometry (FE-SEM-EDS) and X-ray diffraction (XRD). The patinas developed in 15 years were compared with an archaeological bronze recovered from the same site after about two thousand years of burial (referred as short-term and long-term interaction, respectively). Results revealed a similar corrosion behavior, especially in terms of chemical composition and corrosion mechanisms. XRD detected the ubiquitous presence of cuprite, copper hydroxychlorides and terrigenous minerals, while OM and FE-SEM-EDS analyses of cross-sections evidenced similar patinas’ stratigraphy, identifying decuprification as driving corrosion mechanism. However, some differences related to the type of local environment and to the time spent in soil were evidenced. In particular, patinas developed in situ are more heterogeneous and rougher, while the archaeological one is thicker and presents a major amount of cuprite, terrigenous deposits and uncommon corrosion compounds. Based on our findings, the disks buried in situ were selected and used as disposable substrates to study the cleaning effect of a novel polyvinyl alcohol (PVA)-based gel loaded with a chelating agent (Na2EDTA · 2H2O). Results show that the gel is effective in removing disfiguring degradation compounds and preserving the stable and protective patina. Based on the conservation needs, the time of application can be properly tuned. It is worth noticing that after a few minutes the green corrosion products can be selectively removed. The EDS analysis performed on the gels after cleaning reveals that they are highly selective for the removal of copper(II) compounds rather than Cu(I) oxide or Cu(0) from bronze substrates. |
| first_indexed | 2024-03-11T20:51:00Z |
| format | Article |
| id | doaj.art-d59b1661cd5a40369b8762e4ffd60816 |
| institution | Directory Open Access Journal |
| issn | 2405-8440 |
| language | English |
| last_indexed | 2024-03-11T20:51:00Z |
| publishDate | 2023-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Heliyon |
| spelling | doaj.art-d59b1661cd5a40369b8762e4ffd608162023-10-01T06:00:32ZengElsevierHeliyon2405-84402023-09-0199e19626Reproducing bronze archaeological patinas through intentional burial: A comparison between short- and long-term interactions with soilFrancesca Boccaccini0Cristina Riccucci1Elena Messina2Marianna Pascucci3Ferdinando Bosi4David Chelazzi5Teresa Guaragnone6Piero Baglioni7Gabriel Maria Ingo8Gabriella Di Carlo9Institute for the Study of Nanostructured Materials (ISMN), National Research Council (CNR), Via Salaria km 29300, 00015 Monterotondo, Italy; Department of Earth Sciences, Sapienza University of Rome, Piazzale Aldo Moro, 5, I-00185 Rome, Italy; Corresponding author. Department of Earth Sciences, Sapienza University of Rome, Piazzale Aldo Moro, 5, I-00185 Rome, Italy.Institute for the Study of Nanostructured Materials (ISMN), National Research Council (CNR), Via Salaria km 29300, 00015 Monterotondo, ItalyInstitute for the Study of Nanostructured Materials (ISMN), National Research Council (CNR), Via Salaria km 29300, 00015 Monterotondo, ItalyInstitute for the Study of Nanostructured Materials (ISMN), National Research Council (CNR), Via Salaria km 29300, 00015 Monterotondo, ItalyDepartment of Earth Sciences, Sapienza University of Rome, Piazzale Aldo Moro, 5, I-00185 Rome, ItalyDepartment of Chemistry “Ugo Schiff” and CSGI, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence (Italy)CSGI and Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence (Italy)CSGI and Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence (Italy)Institute for the Study of Nanostructured Materials (ISMN), National Research Council (CNR), Via Salaria km 29300, 00015 Monterotondo, ItalyInstitute for the Study of Nanostructured Materials (ISMN), National Research Council (CNR), Via Salaria km 29300, 00015 Monterotondo, Italy; Corresponding author. Institute for the Study of Nanostructured Materials (ISMN), National Research Council (CNR), Via Salaria km 29300, 00015 Monterotondo, Italy.The reproduction of archaeological corrosion patinas is a key issue for the reliable validation of conservation materials before their use on cultural objects. In this study, bronze disks were intentionally buried for 15 years in the soil of the archaeological site of Tharros, both in laboratory and in situ, with the aim of reproducing corrosion patinas typical of archaeological artifacts to be used as representative surfaces for testing novel cleaning gels. The microstructural, microchemical and mineralogical features of the patinas were analyzed by a multianalytical approach, based on optical microscopy (OM), field emission scanning electron microscopy coupled with energy dispersive spectrometry (FE-SEM-EDS) and X-ray diffraction (XRD). The patinas developed in 15 years were compared with an archaeological bronze recovered from the same site after about two thousand years of burial (referred as short-term and long-term interaction, respectively). Results revealed a similar corrosion behavior, especially in terms of chemical composition and corrosion mechanisms. XRD detected the ubiquitous presence of cuprite, copper hydroxychlorides and terrigenous minerals, while OM and FE-SEM-EDS analyses of cross-sections evidenced similar patinas’ stratigraphy, identifying decuprification as driving corrosion mechanism. However, some differences related to the type of local environment and to the time spent in soil were evidenced. In particular, patinas developed in situ are more heterogeneous and rougher, while the archaeological one is thicker and presents a major amount of cuprite, terrigenous deposits and uncommon corrosion compounds. Based on our findings, the disks buried in situ were selected and used as disposable substrates to study the cleaning effect of a novel polyvinyl alcohol (PVA)-based gel loaded with a chelating agent (Na2EDTA · 2H2O). Results show that the gel is effective in removing disfiguring degradation compounds and preserving the stable and protective patina. Based on the conservation needs, the time of application can be properly tuned. It is worth noticing that after a few minutes the green corrosion products can be selectively removed. The EDS analysis performed on the gels after cleaning reveals that they are highly selective for the removal of copper(II) compounds rather than Cu(I) oxide or Cu(0) from bronze substrates.http://www.sciencedirect.com/science/article/pii/S2405844023068342Bronze patinaSoil-induced degradationCorrosion productsCopper alloysCleaning |
| spellingShingle | Francesca Boccaccini Cristina Riccucci Elena Messina Marianna Pascucci Ferdinando Bosi David Chelazzi Teresa Guaragnone Piero Baglioni Gabriel Maria Ingo Gabriella Di Carlo Reproducing bronze archaeological patinas through intentional burial: A comparison between short- and long-term interactions with soil Heliyon Bronze patina Soil-induced degradation Corrosion products Copper alloys Cleaning |
| title | Reproducing bronze archaeological patinas through intentional burial: A comparison between short- and long-term interactions with soil |
| title_full | Reproducing bronze archaeological patinas through intentional burial: A comparison between short- and long-term interactions with soil |
| title_fullStr | Reproducing bronze archaeological patinas through intentional burial: A comparison between short- and long-term interactions with soil |
| title_full_unstemmed | Reproducing bronze archaeological patinas through intentional burial: A comparison between short- and long-term interactions with soil |
| title_short | Reproducing bronze archaeological patinas through intentional burial: A comparison between short- and long-term interactions with soil |
| title_sort | reproducing bronze archaeological patinas through intentional burial a comparison between short and long term interactions with soil |
| topic | Bronze patina Soil-induced degradation Corrosion products Copper alloys Cleaning |
| url | http://www.sciencedirect.com/science/article/pii/S2405844023068342 |
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