Dataset Information

Elemental and Molecular Segregation in Oil Paintings due to Lead Soap Degradation.

ABSTRACT: The formation of Pb, Zn, and Cu carboxylates (soaps) has caused visible deterioration in hundreds of oil paintings dating from the 15th century to the present. Through transport phenomena not yet understood, free fatty acids in the oil binding medium migrate through the paint and react with pigments containing heavy metals to form soaps. To investigate the complex correlation among the elemental segregation, types of chemical compounds formed, and possible mechanisms of the reactions, a paint sample cross-section from a 15th century oil painting was examined by synchrotron X-ray techniques. X-ray fluorescence (XRF) microscopy, quantified with elemental correlation density distribution, showed Pb and Sn segregation in the soap-affected areas. X-ray absorption near edge structure (XANES) around the Pb-L3 absorption edge showed that Pb pigments and Pb soaps can be distinguished while micro-XANES gave further information on the chemical heterogeneity in the paint film. The advantages and limitations of these synchrotron-based techniques are discussed and compared to those of methods routinely used to analyze paint samples. The results presented set the stage for improving the information extracted from samples removed from works of art and for correlating observations in model paint samples to those in the naturally aged samples, to shed light onto the mechanism of soap formation.

SUBMITTER: Chen-Wiegart YK

PROVIDER: S-EPMC5599643 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature

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Elemental and Molecular Segregation in Oil Paintings due to Lead Soap Degradation.

Chen-Wiegart Yu-Chen Karen YK Catalano Jaclyn J Williams Garth J GJ Murphy Anna A Yao Yao Y Zumbulyadis Nicholas N Centeno Silvia A SA Dybowski Cecil C Thieme Juergen J

Scientific reports 20170914 1

The formation of Pb, Zn, and Cu carboxylates (soaps) has caused visible deterioration in hundreds of oil paintings dating from the 15th century to the present. Through transport phenomena not yet understood, free fatty acids in the oil binding medium migrate through the paint and react with pigments containing heavy metals to form soaps. To investigate the complex correlation among the elemental segregation, types of chemical compounds formed, and possible mechanisms of the reactions, a paint sa ...[more]

PMID: 28912460

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Dataset Information

Elemental and Molecular Segregation in Oil Paintings due to Lead Soap Degradation.

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Elemental and Molecular Segregation in Oil Paintings due to Lead Soap Degradation.

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