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Uffelman E.S.,Washington and Lee University | Hobbs P.A.,Washington and Lee University | Barisas D.A.G.,Washington and Lee University | Mass J.L.,Scientific Research and Analysis Laboratory
Applied Physics A: Materials Science and Processing | Year: 2013

Portable X-ray Fluorescence Spectrometry (pXRF) was used to survey 33 works in Washington and Lee University's collection of Louise Herreshoff's paintings. This work was done both to support a condition assessment of the paintings and their pigments and to determine which paintings might be appropriate for further study in the context of ongoing key synchrotron research into the degradation mechanisms of cadmium sulfide yellow pigment (CdS). © 2013 Springer-Verlag Berlin Heidelberg.

Mass J.L.,Scientific Research and Analysis Laboratory | Opila R.,University of Delaware | Buckley B.,Barnes Foundation | Cotte M.,European Synchrotron Radiation Facility | And 3 more authors.
Applied Physics A: Materials Science and Processing | Year: 2013

Evidence for the alteration of the yellow paints in Henri Matisse's Le Bonheur de vivre (1905-1906, The Barnes Foundation) has been observed since the 1990s. The changes in this iconic work of Matisse's Fauvist period include lightening, darkening, and flaking of the yellow paints. Handheld X-ray fluorescence (XRF) and multispectral imaging surveys reveal that the degradation is confined to cadmium yellow (CdS) paints. The discoloration of cadmium yellow paints in Impressionist, Post-Impressionist and early modernist work from the 1880s through the 1920s has been ascribed to the photo-oxidative degradation of CdS. Preliminary investigations of the degraded yellow paints in this work involved Cd LIII-edge X-ray Absorption Near Edge Spectroscopy (XANES) at the Stanford Synchrotron Radiation Light Source (SSRL Menlo Park, California) and Scanning Electron Microscopy-energy dispersive X-ray analysis (SEM-EDS) at the Winterthur Museum Scientific Research and Analysis Laboratory. To determine if the visual changes in the paints did in fact indicate photo-oxidative degradation and if different chemistries could be observed for the lightened versus darkened regions, synchrotron radiation-micro Fourier Transform InfraRed (SR-μFTIR) spectroscopy, X-ray Fluorescence (SR-μXRF) mapping and micro X-ray Absorption Near Edge Spectroscopy (μXANES) mapping at the Cd LIII-edge of the altered paint cross-sections were carried out at the European synchrotron radiation facility (ESRF, Grenoble, France) beamline ID-21. The goal is to elucidate the discoloration mechanisms observed in the paint using elemental and speciation mapping. The μXANES mapping and SR-FTIR imaging showed a substantial enrichment of CdCO3 in the off-white surface crust of the faded/discolored CdS paint. This suggests that the CdCO3 is present as an insoluble photodegradation product rather than solely a paint filler or starting reagent. Additionally, oxalates and sulfates were found to be concentrated at the alteration surface. © 2012 Springer-Verlag Berlin Heidelberg.

Keune K.,University of Amsterdam | Mass J.,Scientific Research and Analysis Laboratory | Meirer F.,University Utrecht | Pottasch C.,Royal Picture Gallery Mauritshuis | And 7 more authors.
Journal of Analytical Atomic Spectrometry | Year: 2015

Realgar and orpiment, arsenic sulfide pigments used in historic paints, degrade under the influence of light, resulting in transparent, whitish, friable and/or crumbling paints. So far, para-realgar and arsenic trioxide have been identified as the main oxidation products of arsenic sulfide pigments. This paper shows that after photo-degradation, various oxidation and migration processes take place. Synchrotron radiation (SR) micro-X-ray fluorescence (μ-XRF) reveals arsenic to be distributed throughout the whole multi-layered paint system. Arsenic (As) K-edge micro-X-ray absorption near edge structure (μ-XANES) analyses indicate the presence of an intact AsxSy pigment, arsenite compounds (As3+; As2O3), and arsenate compounds (As5+); the latter are certainly present as calcium, lead, aluminium and iron arsenates. Sulfur (S) K-edge μ-XANES points to the conversion of the sulfide (S2-) group to a sulfate (SO4 2-) group, probably via an elemental sulfur (S0) or sulfoxide (S2+) compound. Principal Component Analysis (PCA) and subsequent k-means clustering of multi-energy SR μ-XRF maps and μ-XANES were performed to identify the various arsenic species and visualize their distribution. The arsenates (As5+) are spread throughout the entire paint system and dominate the photo-degraded paint and ground layers, while the arsenite compounds (As3+) are located close to the intact arsenic sulfide pigment. The oxidation of arsenic trioxide into arsenates likely takes place in aqueous solutions. The presence of As5+ compounds in the paint systems indicates that the arsenic trioxide is dissolved by ambient water present in the paint. Arsenite and arsenate compounds are water soluble and are transported by water throughout the paint system. This knowledge is crucial for the conservation field, as this is the first time that (indirect) evidence of water transport within paintings has been given. © 2015 The Royal Society of Chemistry.

Pouyet E.,European Synchrotron Radiation Facility | Pouyet E.,CEA Grenoble | Cotte M.,European Synchrotron Radiation Facility | Cotte M.,Lams Laboratoire Darcheologie Moleculaire Et Structurale Umr 8220 | And 12 more authors.
Applied Physics A: Materials Science and Processing | Year: 2015

The chemical and physical alterations of cadmium yellow (CdS) paints in Henri Matisse’s The Joy of Life (1905–1906, The Barnes Foundation) have been recognized since 2006, when a survey by portable X-ray fluorescence identified this pigment in all altered regions of the monumental painting. This alteration is visible as fading, discoloration, chalking, flaking, and spalling of several regions of light to medium yellow paint. Since that time, synchrotron radiation-based techniques including elemental and spectroscopic imaging, as well as X-ray scattering have been employed to locate and identify the alteration products observed in this and related works by Henri Matisse. This information is necessary to formulate one or multiple mechanisms for degradation of Matisse’s paints from this period, and thus ensure proper environmental conditions for the storage and the display of his works. This paper focuses on 2D full-field X-ray Near Edge Structure imaging, 2D micro-X-ray Diffraction, X-ray Fluorescence, and Fourier Transform Infra-red imaging of the altered paint layers to address one of the long-standing questions about cadmium yellow alteration—the roles of cadmium carbonates and cadmium sulphates found in the altered paint layers. These compounds have often been assumed to be photo-oxidation products, but could also be residual starting reagents from an indirect wet process synthesis of CdS. The data presented here allow identifying and mapping the location of cadmium carbonates, cadmium chlorides, cadmium oxalates, cadmium sulphates, and cadmium sulphides in thin sections of altered cadmium yellow paints from The Joy of Life and Matisse’s Flower Piece (1906, The Barnes Foundation). Distribution of various cadmium compounds confirms that cadmium carbonates and sulphates are photo-degradation products in The Joy of Life, whereas in Flower Piece, cadmium carbonates appear to have been a [(partially) unreacted] starting reagent for the yellow paint, a role previously suggested in other altered yellow paints. © 2015 Springer-Verlag Berlin Heidelberg

Voras Z.E.,University of Delaware | deGhetaldi K.,University of Delaware | Wiggins M.B.,University of Delaware | Buckley B.,The Barnes Foundation | And 3 more authors.
Applied Physics A: Materials Science and Processing | Year: 2015

Time-of-flight secondary ion mass spectrometry (ToF–SIMS) has recently been shown to be a valuable tool for cultural heritage studies, especially when used in conjunction with established analytical techniques in the field. The ability of ToF–SIMS to simultaneously image inorganic and organic species within a paint cross section at micrometer-level spatial resolution makes it a uniquely qualified analytical technique to aid in further understanding the processes of pigment and binder alteration, as well as pigment–binder interactions. In this study, ToF–SIMS was used to detect and image both molecular and elemental species related to CdS pigment and binding medium alteration on the painting Le Bonheur de vivre (1905–1906, The Barnes Foundation) by Henri Matisse. Three categories of inorganic and organic components were found throughout LeBonheur de vivre and co-localized in cross-sectional samples using high spatial resolution ToF–SIMS analysis: (1) species relating to the preparation and photo-induced oxidation of CdS yellow pigments (2) varying amounts of long-chain fatty acids present in both the paint and primary ground layer and (3) specific amino acid fragments, possibly relating to the painting’s complex restoration history. ToF–SIMS’s ability to discern both organic and inorganic species via cross-sectional imaging was used to compare samples collected from LeBonheur de vivre to artificially aged reference paints in an effort to gather mechanistic information relating to alteration processes that have been previously explored using μXANES, SR-μXRF, SEM–EDX, and SR-FTIR. The relatively high sensitivity offered by ToF–SIMS imaging coupled to the high spatial resolution allowed for the positive identification of degradation products (such as cadmium oxalate) in specific paint regions that have before been unobserved. The imaging of organic materials has provided an insight into the extent of destruction of the original binding medium, as well as identifying unexpected organic materials in specific paint layers. © 2015, Springer-Verlag Berlin Heidelberg.

Bradley L.P.,200 Getty Center Drive | Meloni S.,Royal Picture Gallery Mauritshuis Mauritshuis | Uffelman E.S.,Washington and Lee University | Mass J.L.,Scientific Research and Analysis Laboratory
ACS Symposium Series | Year: 2012

Gijsbert Gillisz d'Hondecoeter's (1604-1653) panel painting, Cock and Hens in a Landscape, recently underwent complete treatment and technical examination at The Royal Picture Gallery Mauritshuis, The Hague (inv. no. 405). The interdisciplinary application of art historical research, conservation methodology, and scientific investigation led to several discoveries about the painting, including the revelation that major compositional elements of iconographical significance had been overpainted at some point in its history. Technical examination suggested that the original paint was in sufficiently good condition for the overpaint to be removed. The painting is currently on permanent display at the Prince William V Gallery in a state closer to the painter's original artistic intent. © 2012 American Chemical Society.

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