Contribution to the identification of α-, β- and ε-copper phthalocyanine blue pigments in modern artists' paints by X-ray powder diffraction, attenuated total reflectance micro-fourier transform infrared spectroscopy and micro-Raman spectroscopy

in Journal of Raman Spectroscopy (2012), 43

Since the end of the 20th century, the α-, β- and ε-copper phthalocyanine (CuPc) blue pigments are widely used in modern artists' paints. The identification of the CuPc crystalline structure can provide ... [more ▼]

Since the end of the 20th century, the α-, β- and ε-copper phthalocyanine (CuPc) blue pigments are widely used in modern artists' paints. The identification of the CuPc crystalline structure can provide useful technical and chronological information for the study of works of art. Although when a CuPc blue pigment is identified, its crystalline structure often remains unspecified despite the interest for conservation science. In this study, X-ray powder diffraction, attenuated total reflectance micro-Fourier transform infrared spectroscopy and micro-Raman spectroscopy analyses have been carried out on 15 dry pigment samples of CuPc and acrylic, vinylic, alkyd, arabic gum and oil-based artists' paints. By using the polymorphic markers underlined for dry pigments, the CuPc crystalline structure has been successfully identified for most of the analysed artists' paints. However, according to the analytical technique used and the investigated paint sample, the obtained results largely differ. © 2012 John Wiley & Sons, Ltd. [less ▲]

X-ray production cross-sections measurements for high-energy alpha particle beams: New dedicated set-up and first results with aluminum

in Nuclear Instruments & Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms (2011), 269(24), 29792983

The “IPNAS” laboratory, in collaboration with the “Centre Européen d’Archéométrie” is partly focused on material analysis by means of IBA techniques: PIXE, PIGE and RBS. A new transport beam line has been ... [more ▼]

The “IPNAS” laboratory, in collaboration with the “Centre Européen d’Archéométrie” is partly focused on material analysis by means of IBA techniques: PIXE, PIGE and RBS. A new transport beam line has been developed at our CGR-520 MeV cyclotron to analyze Cultural Heritage objects using these techniques. This facility allows us to produce proton and alpha particle beams with energies up to 20 MeV. A vacuum chamber dedicated to X-ray production and Non-Rutherford cross-section measurements has been recently constructed. After determination of the chamber’s geometry for X-ray detection using thin foils of several elements (11 ⩽ Z ⩽ 82) and 3 MeV proton beams, the measurement of the X-ray production cross-sections in the 6–12 MeV energy range has started using alpha particle beams on light element targets. These experiments contribute to the filling a serious lack of experimental values for alpha particles of this particular energy range in databases. The recent decision to focus our work on the alpha particle interaction with light elements was taken because of the high interest of the low Z elements in the field of archaeometry. [less ▲]

Insights into the ancient methods of preparation of Prussian blue pigments by high-resolution powder diffraction and PDF analysis

Conference (2011, September 09)

Caractérisation et vieillissement accéléré de pigments de bleu de Prusse synthétisés selon les méthodes de préparation anciennes et modernes

Conference (2011, April 11)

Verre Mérovingien dans la vallée Mosane - apport de l'archéométrie à l'étude des techniques et à l'histoire économique

Conference (2011, April)

Fading of modern Prussian blue pigments in linseed oil medium

Poster (2011, February 04)

Rapport Annuel du Centre Européen d'Archéométrie 2010

Report (2011)

TiO2 mesoporous thin films studied by Atmospheric Ellipsometric Porosimetry: A case of contamination

in Microporous & Mesoporous Materials (2011), 147

Anatase mesoporous TiO2 thin films are frequently prepared by surfactant templating to control porosity development and Atmospheric Ellipsometric Porosimetry is a reliable and fast technique allowing the ... [more ▼]

Anatase mesoporous TiO2 thin films are frequently prepared by surfactant templating to control porosity development and Atmospheric Ellipsometric Porosimetry is a reliable and fast technique allowing the determination of the porosity of such films. After prolonged exposition to high-vacuum (6×10-6 mbar), the films porosity exhibits a degraded behavior during porosimetric measurements, indicating a vacuum-induced modification. The main effect resulting from such exposition to high-vacuum is a wet- tability modification of the films, resulting in an increase of the hydrophobic character of the TiO2 surface. This evolution induces non-correct results in porosimetric measurements due to the fact that the contact angle parameter needed to calculate the pore size distribution is highly different from the reference films. A surface contamination explains such modifications and a restoration of the films is obtained by using ultraviolet treatment. [less ▲]

Direct analysis of the central panel of the so-called Wyts triptych after Jan van Eyck

in Journal of Raman Spectroscopy (2010), 41(11), 1210-1219

The applicability of mobile, non-destructive techniques such as energy dispersive X-ray fluorescence spectroscopy, which reveals the elemental composition, and fibre-coupled Raman spectroscopy, offering ... [more ▼]

The applicability of mobile, non-destructive techniques such as energy dispersive X-ray fluorescence spectroscopy, which reveals the elemental composition, and fibre-coupled Raman spectroscopy, offering molecular information, is applied to the central panel of the Wyts triptych, after Jan van Eyck. Using a combination of these direct techniques, vermilion (HgS), lead white (2PbCO3·Pb(OH)2), anatase (TiO2), massicot (PbO), zinc white (ZnO) and lead-tin yellow type I (Pb2SnO4) could be identified. X-ray fluorescence spectroscopy (XRF) measurements also confirmed the presence of cobalt. Also, copper was detected in different blue and green areas. For the brown and red colour, iron oxides were used. Apart from identifying pigments, the combination of these analytical techniques also gave information about restored parts and the layered structure of the panel. XRF maps of three different areas of the panel painting were recorded to get an idea of the changes the painting underwent during its past history. This research confirms the results of the visual analysis that the painting is a heavily restored copy of a lost original by Jan van Eyck. [less ▲]

Elemental 2D imaging of paintings with a XRF mobile system

Conference (2010, July)