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Temperature-related degradation and colour changes of historic paintings containing vivianite

SYSNO ASEP	0442179
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Temperature-related degradation and colour changes of historic paintings containing vivianite
Author(s)	Čermáková, Zdeňka (UACH-T)_SAI Švarcová, Silvie (UACH-T)_{SAI, RID, ORCID} Hradilová, J. (CZ) Bezdička, Petr (UACH-T)_{SAI, RID, ORCID} Lančok, Adriana (UACH-T)_{ORCID, RID, SAI} Vašutová, V. (CZ) Blažek, Jan (UTIA-B)_{RID, ORCID} Hradil, David (UACH-T)_{RID, SAI}
Source Title	Spectrochimica Acta Part A-Molecular and Biomolecular Spectroscopy. - : Elsevier - ISSN 1386-1425 Roč. 140, APR (2015), s. 101-110
Number of pages	10 s.
Language	eng - English
Country	NL - Netherlands
Keywords	Degradation ; High-temperature X-ray diffraction ; Model experiments ; Mossbauer spectroscopy ; Vivianite
Subject RIV	CA - Inorganic Chemistry
OECD category	Inorganic and nuclear chemistry
R&D Projects	GAP103/12/2211 GA ČR - Czech Science Foundation (CSF)
Institutional support	UACH-T - RVO:61388980 ; UTIA-B - RVO:67985556
UT WOS	000350939200012
EID SCOPUS	84937107577
DOI	10.1016/j.saa.2014.12.082
Annotation	Temperature-related degradation of pure synthetic as well as partly oxidised natural vivianite has been studied by high-temperature X-ray diffraction (HT-XRD) covering the whole extent of the temperature-related stability of its structure. While temperatures around 70°C are already damaging to vivianite, exposition to 160°C results in complete amorphisation of both the vivianite and its oxidation products. As indicated by Mossbauer spectroscopy, temperature-induced oxidation of vivianite starts at 90°C. To study the occurring structural as well as accompanying colour changes in more detail, model vivianite paint layer samples with different historic binders were prepared and subjected to increased temperatures. Exposition to 80°C caused pronounced colour changes of all the samples: ground natural blue vivianite became grey - a colour change which has been described in actual works of art. Regarding the binders, the oil seemed to facilitate the transfer of heat to vivianite's grains. To simulate conditions of conservation treatment under which the painting is exposed to increased temperatures, oil-on-canvas mock-ups with vivianite were prepared and relined in a traditional way using iron. The treatment affected preferentially larger grains of vivianite; the micro-samples documented their change to grey, and their Raman spectra showed the change from vivianite to metavivianite.
Workplace	Institute of Inorganic Chemistry
Contact	Jana Kroneislová, krone@iic.cas.cz, Tel.: 311 236 931
Year of Publishing	2016

Number of the records: 1