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Author |
Terzano, R.; Spagnuolo, M.; Medici, L.; Dorriné, W.; Janssens, K.; Ruggiero, P. |
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Title |
Microscopic single particle characterization of zeolites synthesized in a soil polluted by copper or cadmium and treated with coal fly ash |
Type |
A1 Journal article |
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Year |
2007 |
Publication  |
Applied clay science |
Abbreviated Journal |
Appl Clay Sci |
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Volume |
35 |
Issue |
1-2 |
Pages |
128-138 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Wos |
000243825800016 |
Publication Date |
2006-09-12 |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0169-1317 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.101 |
Times cited |
17 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.101; 2007 IF: 1.861 |
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Call Number |
UA @ admin @ c:irua:62999 |
Serial |
5723 |
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Author |
Benito, P.; Nuyts, G.; Monti, M.; de Nolf, W.; Fornasari, G.; Janssens, K.; Scavetta, E.; Vaccari, A. |
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Title |
Stable Rh particles in hydrotalcite-derived catalysts coated on FeCrAlloy foams by electrosynthesis |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Applied catalysis : B : environmental |
Abbreviated Journal |
Appl Catal B-Environ |
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Volume |
179 |
Issue |
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Pages |
321-332 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Rh-based structured catalysts for the Catalytic Partial Oxidation of CH4 to syngas were prepared by electrosynthesis of Rh/Mg/Al hydrotalcite-type compounds on FeCrAlloy foams and calcination. The effects of Rh content, total metal concentration, and partial replacement of Mg2+ by Ni2+ in the electrolytic solution on coating thickness, Rh speciation, metallic particle size, and catalytic activity were investigated by SEM/EDS, mu-XRF/XANES and tests under diluted and concentrated reaction conditions. The amount of Rh species, present as Mg (RhxAl1-x)(2)O-4, depended on the thickness of the electrosynthesised layer as well as the Rh particle size and dispersion. Smaller and more dispersed particles were obtained by decreasing the Rh concentration in the electrolytic solution from Rh/Mg/Al=11/70/19 to 5/70/25 and 2/70/28 atomic ratio% (a.r.%) and in thinner rather than thicker layers. Despite the improvement in metallic particles features, the CH4 conversion was negatively affected by the low amount of active sites in the coating, the high metal support interaction and possibly the oxidation of metallic particles and carbon formation. A larger amount of solid containing well dispersed Rh particles was deposited by increasing the total metal concentration from 0.03 M to 0.06 M with the Rh/Mg/Al=5/70/25 a.r.%, and the catalytic performances were enhanced. The partial replacement of Mg2+ by Ni2+ gave rise to a very active bimetallic Rh/Ni catalyst, CH4 conversion and selectivity to syngas were above 90%, however, it slightly deactivated with time-on-stream. (C) 2015 Elsevier B.V. All rights reserved. |
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Wos |
000359873800036 |
Publication Date |
2015-05-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0926-3373 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.446 |
Times cited |
14 |
Open Access |
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Notes |
; The Authors acknowledge M. Salome for helping during the mu XRF/XANES experiments at ID21 Beamline of the ESRF, the Department of Structural Characterisation of CNR-IMM of Bologna for the access to the FEG-SEM facility and Dr F. Ospitali for the scientific support. Thanks are due to Farrel Lytle database for providing the necessary Rh metal spectrum (rhfoil.a99 in http:// ixs.iit.edu/data/FarrelLytledata/). The financial support from the Ministero per l'Istruzione, l'Universita e la Ricerca (MIUR, Roma, Italy) and the University of Bologna (FARB program) is gratefully acknowledged. ; |
Approved |
Most recent IF: 9.446; 2015 IF: 7.435 |
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Call Number |
UA @ admin @ c:irua:127777 |
Serial |
5846 |
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Author |
Janssens, K.; Alfeld, M.; van der Snickt, G.; de Nolf, W.; Vanmeert, F.; Radepont, M.; Monico, L.; et al. |
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Title |
The use of synchrotron radiation for the characterization of artists' pigments and paintings |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Annual review of analytical chemistry |
Abbreviated Journal |
Annu Rev Anal Chem |
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Volume |
6 |
Issue |
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Pages |
399-425 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
We review methods and recent studies in which macroscopic to (sub)microscopic X-ray beams were used for nondestructive analysis and characterization of pigments, paint microsamples, and/or entire paintings. We discuss the use of portable laboratory- and synchrotron-based instrumentation and describe several variants of X-ray fluorescence (XRF) analysis used for elemental analysis and imaging and combined with X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). Macroscopic and microscopic (μ-)XRF variants of this method are suitable for visualizing the elemental distribution of key elements in paint multilayers. Technical innovations such as multielement, large-area XRF detectors have enabled such developments. The use of methods limited to elemental analysis or imaging usually is not sufficient to elucidate the chemical transformations that take place during natural pigment alteration processes. However, synchrotron-based combinations of μ-XRF, μ-XAS, and μ-XRD are suitable for such studies. |
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Wos |
000323887500019 |
Publication Date |
2013-06-18 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1936-1327 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
7.435 |
Times cited |
46 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 7.435; 2013 IF: 7.814 |
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Call Number |
UA @ admin @ c:irua:111315 |
Serial |
5902 |
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Author |
Odin, G.P.; Vanmeert, F.; Janssens, K.; Lelièvre, H.; Mertz, J.-D.; Rouchon, V. |
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Title |
Accelerated ageing of shales of palaeontological interest : impact of temperature conditions |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Annales de paléontologie |
Abbreviated Journal |
Ann Paleontol |
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Volume |
100 |
Issue |
2 |
Pages |
137-149 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The palaeontological collections of the Muséum national dHistoire naturelle (MNHN, Paris, France) and the Muséum dHistoire naturelle dAutun (MHNA, Autun, France) include many fossil specimens originating from the argillaceous shales of the Autun basin (Saône-et-Loire, France). These fossils are preserved within sedimentary rocks containing unstable sulphide compounds, such as pyrite, which may deteriorate in contact with water and oxygen. This alteration provokes crystalline efflorescence and cracks, thus compromising the preservations of the fossils. This work constitutes the first step of a project that aims to understand the mechanisms of alteration of these materials in order to define conservation guidelines for palaeontological collections. For this purpose, eight damaged specimens originating from the Permian Autun basin (Saône-et-Loire, France) were selected and analyzed by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy coupled to energy dispersive X-ray spectrometry (SEM/EDS) and X-ray absorption spectroscopy at the threshold of the sulphur Kα-edge (XANES). This methodology enabled the characterization of the matrices composition and the chemical nature of the alterations. Subsequently, we have sought to reproduce by artificial ageing the alteration phenomena encountered in the collections. New shale samples were collected on seven outcrops of the same Autun basin. They were analyzed and subjected to artificial ageing at 50% relative humidity (RH) and at temperatures ranging between 40 °C and 90 °C. Our work shows that damaged specimens and newly collected shale have a similar mineralogical composition. Yet the crystalline efflorescence material formed on the surface of damaged specimens belongs to the iron sulphate group whereas gypsum predominates on artificially aged shale samples. Reproducing the alterations observed on specimens by artificial ageing remains therefore problematic. Additionally, it appears that the temperature of ageing controls the nature of the damage: at 40 °C, many samples are mechanically damaged whereas no or minor crystalline efflorescence occurs. At 90 °C, it is the opposite tendency that is observed. Finally, mechanical damages do not seem to be correlated with the development of the efflorescence: samples with efflorescent crystals generally do not show clearly visible cracks; those that seem most fragmented do not show any visible efflorescence. |
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Wos |
000338607500006 |
Publication Date |
2014-01-24 |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
0753-3969 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.113 |
Times cited |
5 |
Open Access |
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Notes |
; This work is part of a PhD that is funded by the Museum national d'Histoire naturelle, Paris, France and was additionally supported via the S2-ART project (SDD programme of BELSPO, Brussels). The research was realized in partnership with the Palaeontological Collection Management Unit, Collection Department and with the Centre de Recherche sur la Paleodiversite et les Paleoenvironnements (CR2P, CNRS, UMR7207) of the Museum national d'Histoire naturelle, Paris, France. We are grateful to our colleagues MM. Jean Dejax and Dominique Chabard who provided palaeontological specimens and gave us access to shale deposits and Mrs Marie-Madeleine Blanc-Valleron who was of great help for the interpretation of the XRD data. ; |
Approved |
Most recent IF: 1.113; 2014 IF: 0.970 |
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Call Number |
UA @ admin @ c:irua:116594 |
Serial |
5456 |
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Author |
Odin, G.P.; Vanmeert, F.; Farges, F.; Gand, G.; Janssens, K.; Romero-Sarmiento, M.-F.; Steyer, J.S.; Vantelon, D.; Rouchon, V. |
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Title |
Alteration of fossil-bearing shale (Autun, France; Permian), part II : monitoring artificial and natural ageing by combined use of S and Ca K-edge XANES analysis, Rock-Eval pyrolysis and FTIR analysis |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Annales de paléontologie |
Abbreviated Journal |
Ann Paleontol |
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Volume |
101 |
Issue |
3 |
Pages |
225-239 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Fossil-bearing shale specimens that include sulfides in their compositions are chemically reactive and sometimes also mechanically fragile. This decay is often related to iron sulfate efflorescence resulting from the oxidation of sulfide compounds. The processes underlying these degradations are poorly known, thus impeding the elaboration of curative or preventive treatments. The present contribution aims to identify the origin of museum specimen alterations. It focuses on the Flouest collection housed at the Museum National d'Histoire Naturelle (MNHN, Paris, France) and originating from the Autun Basin (Saone-et-Loire, France, Permian). To evaluate the alteration of MNHN specimens, it appeared necessary to compare their composition with that of unaltered shale so as to identify chemical changes occurring during ageing. Therefore, new material was collected in the Autun Basin, among others on the locality of Muse that corresponds to the same lithostratigraphic unit as that of the MNHN specimens. This material was, if necessary, artificially aged. The first part of this work, presented elsewhere, deals with the use of Xray diffraction and Mossbauer spectroscopy for characterizing iron reactivity and speciation. It leads to the conclusion that the reactivity of iron in the shale matrix was limited and could not account for the large efflorescence of iron (II) sulfate occurring nearby the fossil. The second part presented here focuses on the use of S K-edge X-ray Absorption Near Edge Structure (XANES) spectroscopy for characterizing sulfur speciation and reactivity. Measurements were performed on the shale matrix and on thin layers of maceral found in the proximity of damaged areas. As sulfur may be found in association with calcium or organic matter, complementary techniques were implemented, such as FTIR spectroscopy, Rock-Eval pyrolysis (characterization of organic matter content) and Ca K-edge XANES (analysis of calcium speciation) spectroscopy. It was shown that sulfur is mainly related to thioether, sulfoxide, iron sulfide, and sulfates whereas calcium is mainly bound to carboxylate, carbonate and/or sulfate groups. FTIR analysis of the macerals confirmed the presence of vitrinite on damaged MNHN specimens. The low oxygen content of new shale samples determined by Rock-Eval pyrolysis indicates that the organic matter is well preserved, despite the fact that samples come from outcrop surface. In the newly collected material, sulfur is mainly related to organic sulfides (thioether) with a minor occurrence of iron sulfide. In the shale fraction of damaged MNHN specimens, sulfur is mostly oxidized into a mixture of iron and calcium sulfate. However, in the vitrinite layers of the same specimens, a large proportion of sulfur corresponds to organic sulfides. Also the oxidation of sulfur does not occur homogeneously but preferentially in the shale fraction, probably because this latter is porous whereas vitrinite is not. Artificial ageing of new shale material showed that the oxidation of organic sulfides could be reproduced at 90 degrees C, 80% of relative humidity. However, the obtained efflorescence almost exclusively corresponds to calcium sulfate whereas iron (II) sulfates are mostly observed on MNHN specimens. The new material collected on site is probably to be questioned, and future studies will have to select new samples with fossil remains. This will be the object of the third part of this work. (C) 2015 Elsevier Masson SAS. All rights reserved. |
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Wos |
000363821700009 |
Publication Date |
2015-05-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0753-3969 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.113 |
Times cited |
6 |
Open Access |
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Notes |
; This work was conducted within a PhD work that was supported by a doctoral school grant of the Museum national d'Histoire naturelle, Paris, France. We acknowledge SOLEIL for provision of synchrotron radiation facilities (Proposals ID “20130462” and “20110189”) and we would like to thank Nicolas Trcera, Pierre Lagarde and Anne Marie Flanck for assistance in using beamline LUCIA. ; |
Approved |
Most recent IF: 1.113; 2015 IF: 0.970 |
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Call Number |
UA @ admin @ c:irua:129523 |
Serial |
5462 |
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Author |
Tan, H.; Tian, H.; Verbeeck, J.; Janssens, K.; Van Tendeloo, G. |
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Title |
Nanoscale investigation of the degradation mechanism of a historical chrome yellow paint by quantitative electron energy loss spectroscopy mapping of chromium species |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
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Volume |
52 |
Issue |
43 |
Pages |
11360-11363 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Getting the picture: The investigation of 100 year old chrome yellow paint by transmission electron microscopy and spectroscopy has led to the identification of four types of coreshell particles. This nanoscale investigation has allowed a mechanism to be proposed for the darkening of some bright yellow colors in Van Gogh's paintings (e.g. in Falling leaves (Les Alyscamps), 1888). |
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Place of Publication |
Weinheim |
Editor |
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Wos |
000330735800026 |
Publication Date |
2013-09-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1433-7851; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
11.994 |
Times cited |
29 |
Open Access |
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Notes |
Esteem2; Vortex; Countatoms; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 11.994; 2013 IF: 11.336 |
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Call Number |
UA @ lucian @ c:irua:110947UA @ admin @ c:irua:110947 |
Serial |
2266 |
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Author |
Vanmeert, F.; Hendriks, E.; van der Snickt, G.; Monico, L.; Dik, J.; Janssens, K. |
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Title |
Chemical Mapping by Macroscopic X-ray Powder Diffraction (MA-XRPD) of Van Gogh's Sunflowers : identification of areas with higher degradation risk |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
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Volume |
57 |
Issue |
25 |
Pages |
7418-7422 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The discoloration rate of chrome yellow (CY), a class of synthetic inorganic pigments (PbCr1-xSxO4) frequently used by Van Gogh and his contemporaries, strongly depends on its sulfate content and on its crystalline structure (either monoclinic or orthorhombic). Macroscopic X-Ray powder diffraction imaging of selected areas on Van Gogh's Sunflowers (Van Gogh Museum, Amsterdam) revealed the presence of two subtypes of CY: the light-fast monoclinic PbCrO4 (LF-CY) and the light-sensitive monoclinic PbCr1-xSxO4 (x approximate to 0.5; LS-CY). The latter was encountered in large parts of the painting (e.g., in the pale-yellow background and the bright-yellow petals, but also in the green stems and flower hearts), thus indicating their higher risk for past or future darkening. Overall, it is present in more than 50% of the CY regions. Preferred orientation of LS-CY allows observation of a significant ordering of the elongated crystallites along the direction of Van Gogh's brush strokes. |
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Wos |
000434949200023 |
Publication Date |
2018-03-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1433-7851; 0570-0833 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
11.994 |
Times cited |
10 |
Open Access |
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Notes |
; The authors acknowledge financial support from BELSPO (Brussels) S2-ART, the NWO (The Hague) Science4Arts “ReVisRembrandt” project, the GOA Project Solarpaint (University of Antwerp Research Council), and the Interreg Smart*Light project. Raman analyses were performed using the European MOLAB platform, which is financially supported by the Horizon 2020 Programme (IPERION CH Grant 654028). The authors thank the staff of the Van Gogh Museum for their collaboration. ; |
Approved |
Most recent IF: 11.994 |
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Call Number |
UA @ admin @ c:irua:153185 |
Serial |
5517 |
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Author |
Monico, L.; Janssens, K.; Hendriks, E.; Vanmeert, F.; van der Snickt, G.; Cotte, M.; Falkenberg, G.; Brunetti, B.G.; Miliani, C. |
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Title |
Evidence for degradation of the chrome yellows in Van Gogh's sunflowers : a study using noninvasive in situ methods and synchrotron-radiation-based x-ray techniques |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
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Volume |
54 |
Issue |
47 |
Pages |
13923-13927 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
This paper presents firm evidence for the chemical alteration of chrome yellow pigments in Van Gogh's Sunflowers (Van Gogh Museum, Amsterdam). Noninvasive in situ spectroscopic analysis at several spots on the painting, combined with synchrotron-radiation-based X-ray investigations of two microsamples, revealed the presence of different types of chrome yellow used by Van Gogh, including the lightfast PbCrO4 and the sulfur-rich PbCr1-xSxO4 (x approximate to 0.5) variety that is known for its high propensity to undergo photoinduced reduction. The products of this degradation process, i.e., Cr-III compounds, were found at the interface between the paint and the varnish. Selected locations of the painting with the highest risk of color modification by chemical deterioration of chrome yellow are identified, thus calling for careful monitoring in the future. |
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Wos |
000367722500009 |
Publication Date |
2015-10-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1433-7851; 0570-0833 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
11.994 |
Times cited |
24 |
Open Access |
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Notes |
; We acknowledge financial support from the Italian MIUR project SICH-PRIN (2010329WPF_001) and BELSPO (Brussels) Project S2-ART (SD04A), GOA “SOLARPAINT” (Research Fund Antwerp University, BOF-2015), and FWO (Brussels) projects G.0C12.13, G.0704.08, G.01769.09. We thank ESRF (EC-1051, HG-26) and DESY (I-20120312 EC) for beamtime grants received. Noninvasive analysis of Sunflowers were supported by the EU FP7 programme CHARISMA (Grant 228330) and the Fund Inbev-Baillet Latour (Brussels). L.M. acknowledges financial support from the CNR Short Term Mobility Programme-2013. We thank Muriel Geldof, Luc Megens, Suzan de Groot (The Netherlands Cultural Heritage Agency, RCE), Chiara Grazia, David Buti (CNR-ISTM and SMAArt Centre), and the staff of the Van Gogh Museum for their collaboration. ; |
Approved |
Most recent IF: 11.994; 2015 IF: 11.261 |
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Call Number |
UA @ admin @ c:irua:131110 |
Serial |
5617 |
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Author |
Anaf, W.; Janssens, K.; De Wael, K. |
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Title |
Formation of metallic mercury during photodegradation/photodarkening of \alpha-HgS : electrochemical evidence |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
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Volume |
52 |
Issue |
48 |
Pages |
12568-12571 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Das rote Pigment α-HgS neigt in Gegenwart von Licht und Chloridionen zur Schwärzung. Als Grund für die Zersetzung und Entfärbung werden die Bildung von (schwarzem) β-HgS oder Quecksilbermetall vermutet, doch diese Substanzen wurden noch nicht auf natürlich oder künstlich zersetzter HgS-Farbe nachgewiesen. Elektrochemische Experimente belegen nun die Bildung von Quecksilbermetall in Gegenwart von Licht und Chloridionen. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000327582900015 |
Publication Date |
2013-10-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1433-7851; 0570-0833 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
11.994 |
Times cited |
19 |
Open Access |
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| |
Notes |
; The authors acknowledge L. Klaassen for valuable discussions and providing samples. We acknowledge financial support from the SDD programme (S2-ART project) of the Belgian Federal Goverment. ; |
Approved |
Most recent IF: 11.994; 2013 IF: 11.336 |
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| |
Call Number |
UA @ admin @ c:irua:111265 |
Serial |
5626 |
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| Permanent link to this record |
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| |
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Author |
van der Snickt, G.; Dubois, H.; Sanyova, J.; Legrand, S.; Coudray, A.; Glaude, C.; Postec, M.; van Espen, P.; Janssens, K. |
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| |
Title |
Large-area elemental imaging reveals Van Eyck's original paint layers on the Ghent altarpiece (1432), rescoping its conservation treatment |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
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| |
Volume |
56 |
Issue |
17 |
Pages |
4797-4801 |
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| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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| |
Abstract |
A combination of large-scale and micro-scale elemental imaging, yielding elemental distribution maps obtained by, respectively non-invasive macroscopic X-ray fluorescence (MA-XRF) and by secondary electron microscopy/energy dispersive X-ray analysis (SEM-EDX) and synchrotron radiation-based micro-XRF (SR m-XRF) imaging was employed to reorient and optimize the conservation strategy of van Eyck's renowned Ghent Altarpiece. By exploiting the penetrative properties of X-rays together with the elemental specificity offered by XRF, it was possible to visualize the original paint layers by van Eyck hidden below the overpainted surface and to simultaneously assess their condition. The distribution of the high-energy Pb-L and Hg-L emission lines revealed the exact location of hidden paint losses, while Fe-K maps demonstrated how and where these lacunae were filled-up using an iron-containing material. The chemical maps nourished the scholarly debate on the overpaint removal with objective, chemical arguments, leading to the decision to remove all skillfully applied overpaints, hitherto interpreted as work by van Eyck. MA-XRF was also employed for monitoring the removal of the overpaint during the treatment phase. To gather complementary information on the in-depth layer build-up, SEM-EDX and SR mu-XRF imaging was used on paint cross sections to record microscale elemental maps. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000398576000019 |
Publication Date |
2017-03-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
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Series Issue |
|
Edition |
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| |
ISSN |
1433-7851; 0570-0833 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
11.994 |
Times cited |
11 |
Open Access |
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| |
Notes |
; This research was supported by the Baillet Latour fund, the Belgian Science Policy Office (Projects MO/39/011) and the Gieskes-Strijbis fund. The authors are also indebted to the BOF-GOA SOLAR Paint project of the University of Antwerp Research Council. The church wardens of the cathedral of St. Bavo and their chairman L. Collin are acknowledged for this agreeable collaboration. We also wish to thank conservators L. Depuydt, B. De Volder, F. Rosier, N. Laquiere and G. Steyaert as well as the members of the international committee. We are indebted to Prof. Em. A. Van Grevenstein-Kruse. ; |
Approved |
Most recent IF: 11.994 |
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| |
Call Number |
UA @ admin @ c:irua:142376 |
Serial |
5688 |
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| Permanent link to this record |
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Author |
Miliani, C.; Monico, L.; Melo, M.J.; Fantacci, S.; Angelin, E.M.; Romani, A.; Janssens, K. |
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| |
Title |
Photochemistry of Artists' Dyes and Pigments : towards better understanding and prevention of colour change in works of art |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
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| |
Volume |
57 |
Issue |
25 |
Pages |
7324-7334 |
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| |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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| |
Abstract |
The absorption of light gives a pigment its colour and its reason for being, but it also creates excited states, that is, new molecules with an energy excess that can be dissipated through degradation pathways. Photodegradation processes provoke long-term, cumulative and irreversible colour changes (fading, darkening, blanching) of which the prediction and prevention are challenging tasks. Of all the environmental risks that affect heritage materials, light exposure is the only one that cannot be controlled without any impact on the optimal display of the exhibit. Light-induced alterations are not only associated with the pigment itself but also with its interactions with support/binder and, in turn, are further complicated by the nature of the environmental conditions. In this Minireview we investigate how chemistry, encompassing multi-scale analytical investigations of works of art, computational modelling and physical and chemical studies contributes to improve our prediction of artwork appearance before degradation and to establish effective preventive conservation strategies. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000434949200006 |
Publication Date |
2018-04-26 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1433-7851; 0570-0833 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
11.994 |
Times cited |
10 |
Open Access |
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Notes |
; We acknowledge: ACS and APS for the permission to adapt Figure 1c,d; RSC to adapt Figures 1e, 3c,d and 4a; Wiley and IUCr to adapt Figures 3b and 4b-d; for the detail of a Andean textile in Figure 5, Museum of Fine Arts, Boston, USA; for the illuminated initial in Figure 6, Torre do Tombo (ANTT). Financial support from the H2020 project IPERION-CH (GA. 654028) is gratefully acknowledged. ; |
Approved |
Most recent IF: 11.994 |
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| |
Call Number |
UA @ admin @ c:irua:153184 |
Serial |
5769 |
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| Permanent link to this record |
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Author |
Vanmeert, F.; van der Snickt, G.; Janssens, K. |
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| |
Title |
Plumbonacrite identified by X-ray powder diffraction tomography as a missing link during degradation of red lead in a Van Gogh painting |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
Angew Chem Int Edit |
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| |
Volume |
54 |
Issue |
12 |
Pages |
3607-3610 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Red lead, a semiconductor pigment used by artists since antiquity, is known to undergo several discoloration phenomena. These transformations are either described as darkening of the pigment caused by the formation of either plattnerite (β-PbO2) or galena (PbS) or as whitening by which red lead is converted into anglesite (PbSO4) or (hydro)cerussite (2 PbCO3⋅Pb(OH)2; PbCO3). X-ray powder diffraction tomography, a powerful analytical method that allows visualization of the internal distribution of different crystalline compounds in complex samples, was used to investigate a microscopic paint sample from a Van Gogh painting. A very rare lead mineral, plumbonacrite (3 PbCO3⋅ Pb(OH)2⋅PbO), was revealed to be present. This is the first reported occurrence of this compound in a painting dating from before the mid 20th century. It constitutes the missing link between on the one hand the photoinduced reduction of red lead and on the other hand (hydro)cerussite, and thus sheds new light on the whitening of red lead. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000351178300008 |
Publication Date |
2015-02-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1433-7851; 0570-0833 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
11.994 |
Times cited |
24 |
Open Access |
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| |
Notes |
; The authors acknowledge L. Van der Loeff and M. Leeuwestein (Kroller-Muller Museum) for providing the paint sample. We thank Dr. J. Jaroszewicz (WUT) for performing the CT measurements. This research was carried out at the light source PETRA III at DESY, a member of the Helmholtz Association (HGF). We thank Dr. G. Falkenberg and the members of his team for their assistance in using beam line P06. We acknowledge financial support from the University of Antwerp GOA projects “XANES meets EELS” and “SOLARPaint”, as well as from BELSPO (Brussels) Project S2-ART and FWO (Brussels) project “ESRF-Dubble”. ; |
Approved |
Most recent IF: 11.994; 2015 IF: 11.261 |
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Call Number |
UA @ admin @ c:irua:124620 |
Serial |
5774 |
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| Permanent link to this record |
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Author |
Gonzalez, V.; Fazlic, I.; Cotte, M.; Vanmeert, F.; Gestels, A.; De Meyer, S.; Broers, F.; Hermans, J.; van Loon, A.; Janssens, K.; Noble, P.; Keune, K. |
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Title |
Lead(II) formate in Rembrandt's Night Watch : detection and distribution from the macro- to the micro-scale |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Angewandte Chemie: international edition in English |
Abbreviated Journal |
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Volume |
|
Issue |
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Pages |
1-9 |
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Keywords |
A1 Journal article; Art; Antwerp X-ray Imaging and Spectroscopy (AXIS) |
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Abstract |
The Night Watch, painted in 1642 and on view in the Rijksmuseum in Amsterdam, is considered Rembrandt's most famous work. X-ray powder diffraction (XRPD) mapping at multiple length scales revealed the unusual presence of lead(II) formate, Pb(HCOO)(2), in several areas of the painting. Until now, this compound was never reported in historical oil paints. In order to get insights into this phenomenon, one possible chemical pathway was explored thanks to the preparation and micro-analysis of model oil paint media prepared by heating linseed oil and lead(II) oxide (PbO) drier as described in 17(th) century recipes. Synchrotron radiation based micro-XRPD (SR-mu-XRPD) and infrared microscopy were combined to identify and map at the micro-scale various neo-formed lead-based compounds in these model samples. Both lead(II) formate and lead(II) formate hydroxide Pb(HCOO)(OH) were detected and mapped, providing new clues regarding the reactivity of lead driers in oil matrices in historical paintings. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000920584500001 |
Publication Date |
2023-01-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1433-7851; 0570-0833 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
16.6 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 16.6; 2023 IF: 11.994 |
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Call Number |
UA @ admin @ c:irua:194279 |
Serial |
7318 |
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| Permanent link to this record |
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Author |
Dooley, K.A.; Chieli, A.; Romani, A.; Legrand, S.; Miliani, C.; Janssens, K.; Delaney, J.K. |
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Title |
Molecular fluorescence imaging spectroscopy for mapping low concentrations of red lake pigments : Van Gogh's painting The Olive Orchard |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Angewandte Chemie-International Edition |
Abbreviated Journal |
Angew Chem Int Edit |
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Volume |
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Issue |
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Pages |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Vincent van Gogh used fugitive red lake pigments that have faded in some paintings. Mapping their distribution is key to understanding how his paintings have changed with time. While red lake pigments can be identified from microsamples, in situ identification and mapping remain challenging. This paper explores the ability of molecular fluorescence imaging spectroscopy to identify and, more importantly, map residual non-degraded red lakes. The high sensitivity of this method enabled identification of the emission spectra of eosin (tetrabromine fluorescein) lake mixed with lead or zinc white at lower concentrations than elemental X-ray fluorescence (XRF) spectroscopy used on account of bromine. The molecular fluorescence mapping of residual eosin and two carmine red lakes in van Gogh's The Olive Orchard is demonstrated and compared with XRF imaging spectroscopy. The red lakes are consistent with the composition of paint tubes known to have been used by van Gogh. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000512477200001 |
Publication Date |
2020-01-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1433-7851; 0570-0833 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
16.6 |
Times cited |
2 |
Open Access |
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Notes |
; We thank Damon Conover and Roxanne Radpour for help with the fluorescence self-absorption correction, and Ella Hendricks for discussions about van Gogh~s letters and materials. K.J. and S.L. thank the Research Council of the University of Antwerp for financial support (ID grant 25805 to S.L. and GOA project SolarPaint). Also FWO, Brussels provided financial support (grants G056619N and G054719N). The European research project IPERION-CH, funded by the European Commission, H2020-INFRAIA-2014-2015 (Grant agreement n. 654028) is also acknowledged. ; |
Approved |
Most recent IF: 16.6; 2020 IF: 11.994 |
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Call Number |
UA @ admin @ c:irua:166490 |
Serial |
6563 |
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| Permanent link to this record |
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Author |
Hrdlickova Kuckova, S.; Hamidi-Asl, E.; Sofer, Z.; Marvan, P.; De Wael, K.; Sanyova, J.; Janssens, K. |
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Title |
A simplified protocol for usage of new immuno-SERS probes for detection of casein, collagens and ovalbumin in cross-sections of artworks |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Analytical methods |
Abbreviated Journal |
Anal Methods-Uk |
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Volume |
10 |
Issue |
9 |
Pages |
1054-1062 |
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Keywords |
A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Although it is now relatively straightforward to identify protein binders in works of art, their proper localization within the corresponding layer still represents a significant analytical challenge. Until now, the identification of proteins has mainly been performed by peptide mass fingerprinting using mass spectrometric methods and their localization in polished paint cross-sections have been realized by optical microscopy via the use of fluorescent stain Sypro Ruby (SR). In this work we propose a simplified protocol for immuno-surface enhanced Raman scattering (immuno-SERS) using gold nanoparticles attached to biphenyl-4,4-dithiol (BPDT) as the SERS-nanotag. These nanoparticles are easily obtainable in the lab and have been used to label multilayered mock up samples prepared as cross-sections to estimate the detection limits of the suggested method. The layers contain egg, casein, and different animal glues binders (prepared in various ratios with linseed oil or a carbohydrate component) mixed with the pigments azurite, vermilion and chalk. The sensitivity of staining agent SR is compared to that of the immuno-SERS protocol for the first time. |
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Corporate Author |
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Place of Publication |
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Editor |
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Language |
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Wos |
000426696100017 |
Publication Date |
2018-02-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1759-9660 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.9 |
Times cited |
3 |
Open Access |
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Notes |
; The authors wish to acknowledge the Fund for Scientific Research-Flanders (FWO-Vlaanderen) for the support to act as a Postdoctoral Fellow – Pegasus of the Research Foundation – Flanders, and the grant from Specific University research (MSMT No. 20/2017) from the Czech Republic. This work was supported by the project Advanced Functional Nanorobots (reg. No. CZ.02.1.01/0.0/0.0/15_003/ 0000444 financed by the EFRR). Zdenek Sofer and Petr Marvan were supported by specific university research (MSMT No. 20-SVV/2018). ; |
Approved |
Most recent IF: 1.9 |
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Call Number |
UA @ admin @ c:irua:148803 |
Serial |
5831 |
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| Permanent link to this record |
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Author |
Ceglia, A.; Nuyts, G.; Cagno, S.; Meulebroeck, W.; Baert, K.; Cosyns, P.; Nys, K.; Thienpont, H.; Janssens, K.; Terryn, H. |
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Title |
A XANES study of chromophores : the case of black glass |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Analytical methods |
Abbreviated Journal |
Anal Methods-Uk |
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Volume |
6 |
Issue |
8 |
Pages |
2662-2671 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
We studied the Fe K-edge X-ray absorption near edge (XANES) spectra of several Roman black glass fragments in order to determine the Fe3+/ΣFe ratio of these materials. The selected archaeological glass samples cover the period 1st5th century AD in nine different sites of the North Western provinces of the Roman Empire. The fragments belong to two different compositional groups demonstrating a diachronic evolution: early Roman HMG (High Magnesia Glass) and Roman Imperial LMG (Low Magnesia Glass). The first group contains natural Fe levels (below 2 wt% as Fe2O3), while the LMG has concentrations above 5 wt%. This difference is also reflected by Fe3+/ΣFe values. Low iron glass was produced under strongly reducing conditions in order to obtain the black colour, with average Fe3+/ΣFe values ≈ 0.17. LMG glass is somewhat more oxidised (Fe3+/ΣFe ≈ 0.40.5). While HMG glass required active control of the furnace environment, LMG was made under ambient atmosphere and its higher oxidation degree is mainly determined by the chemistry of the raw glass. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000333524200032 |
Publication Date |
2014-02-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1759-9660 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.9 |
Times cited |
14 |
Open Access |
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Notes |
; The authors are grateful to the staff of beamline L in HASYLAB for their helpful support. The research leading to these results has received funding from the European Union Seventh Framework Programme FP7/2007-2013 under grant agreement no. 265010. Support from the University of Antwerp Research Council through GOA Programme “XANES meets ELNES” is gratefully acknowledged. This work was partly supported by the Research Council of Norway through its Centres of Excellence funding scheme, project number 223268/F50. We would like to thank M. P. Riccardi and E. Basso of the University of Pavia and R. Falcone of the Stazione Sperimentale del Vetro who provided us with the reference glasses. ; |
Approved |
Most recent IF: 1.9; 2014 IF: 1.821 |
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Call Number |
UA @ admin @ c:irua:116596 |
Serial |
5919 |
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Author |
Monico, L.; Janssens, K.; Miliani, C.; Brunetti, B.G.; Vagnini, M.; Vanmeert, F.; Falkenberg, G.; Abakumov, A.; Lu, Y.; Tian, H.; Verbeeck, J.; Radepont, M.; Cotte, M.; Hendriks, E.; Geldof, M.; van der Loeff, L.; Salvant, J.; Menu, M.; |
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Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : 3 : synthesis, characterization, and detection of different crystal forms of the chrome yellow pigment |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
85 |
Issue |
2 |
Pages |
860-867 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The painter, Vincent van Gogh, and some of his contemporaries frequently made use of the pigment chrome yellow that is known to show a tendency toward darkening. This pigment may correspond to various chemical compounds such as PbCrO4 and PbCr1-xSxO4, that may each be present in various crystallographic forms with different tendencies toward degradation. Investigations by X-ray diffraction (XRD), mid-Fourier Transform infrared (FTIR), and Raman instruments (benchtop and portable) and synchrotron radiation-based micro-XRD and X-ray absorption near edge structure spectroscopy performed on oil-paint models, prepared with in-house synthesized PbCrO4 and PbCr1-xSxO4, permitted us to characterize the spectroscopic features of the various forms. On the basis of these results, an extended study has been carried out on historic paint tubes and on embedded paint microsamples taken from yellow-orange/pale yellow areas of 12 Van Gogh paintings, demonstrating that Van Gogh effectively made use of different chrome yellow types. This conclusion was also confirmed by in situ mid-FTIR investigations on Van Goghs Portrait of Gauguin (Van Gogh Museum, Amsterdam). |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000313668400031 |
Publication Date |
2012-10-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700;1520-6882; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.32 |
Times cited |
79 |
Open Access |
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Notes |
Goa; Fwo |
Approved |
Most recent IF: 6.32; 2013 IF: 5.825 |
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Call Number |
UA @ lucian @ c:irua:108707UA @ admin @ c:irua:108707 |
Serial |
631 |
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Author |
Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Verbeeck, J.; Tian, H.; Tan, H.; Dik, J.; Radepont, M.; Cotte, M. |
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Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 1 : artificially aged model samples |
Type |
A1 Journal article |
| |
Year |
2011 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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| |
Volume |
83 |
Issue |
4 |
Pages |
1214-1223 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1−3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr2O3·2H2O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide], is likely. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000287176900011 |
Publication Date |
2011-02-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700;1520-6882; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
113 |
Open Access |
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| |
Notes |
Iuap; Fwo |
Approved |
Most recent IF: 6.32; 2011 IF: 5.856 |
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| |
Call Number |
UA @ lucian @ c:irua:88794UA @ admin @ c:irua:88794 |
Serial |
632 |
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| Permanent link to this record |
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Author |
Rahemi, V.; Sarmadian, N.; Anaf, W.; Janssens, K.; Lamoen, D.; Partoens, B.; De Wael, K. |
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Title |
Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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| |
Volume |
89 |
Issue |
89 |
Pages |
3326-3334 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artists material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr1-xSxO4, with 0≤x≤0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the co-precipitate with lead sulfate (PbCr1-xSxO4) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that on increasing the sulfur(S)-content in chrome yellow, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photo activity is the result. However, the photo activity relative to the Cr content, and thus Cr reduction, of sulfur-rich PbCr1-xSxO4 is found to be much higher compared to the sulfur-poor or non-doped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its co-precipitates are p-type semiconductors, which explains the observed reduction reaction. As understanding this phenomenon is valuable in the field of cultural heritage, this study is the first joint action of photo-electrochemical measurements and first-principles calculations to approve the higher tendency of sulfur-rich lead chromates to darken. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000397478300015 |
Publication Date |
2017-02-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
7 |
Open Access |
OpenAccess |
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Notes |
; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government, department EWI. The BOF-GOA action SOLARPAINT of the University of Antwerp Research Council is acknowledged for financial support. W.A. acknowledges support from BELSPO project S2-ART. Dr. L. Monico and Dr. C. Miliani (ISTM, Perugia) are gratefully acknowledged for helpful discussions and for providing some of the initial batches of the materials studied. ; |
Approved |
Most recent IF: 6.32 |
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| |
Call Number |
UA @ lucian @ c:irua:140886 |
Serial |
4451 |
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| Permanent link to this record |
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Author |
van der Snickt, G.; Dik, J.; Cotte, M.; Janssens, K.; Jaroszewicz, J.; de Nolf, W.; Groenewegen, J.; van der Loeff, L. |
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Title |
Characterization of a degraded cadmium yellow (CdS) pigment in an oil painting by means of synchrotron radiation based X-ray techniques |
Type |
A1 Journal article |
| |
Year |
2009 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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| |
Volume |
81 |
Issue |
7 |
Pages |
2600-2610 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
On several paintings of James Ensor (1860−1949), a gradual fading of originally bright yellow areas, painted with the pigment cadmium yellow (CdS), is observed. Additionally, in some areas exposed to light, the formation of small white-colored globules on top of the original paint surface is observed. In this paper the chemical transformation leading to the color change and to the formation of the globules is elucidated. Microscopic X-ray absorption near-edge spectroscopy (ì-XANES) experiments show that sulfur, originally present in sulfidic form (S2−), is oxidized during the transformation to the sulfate form (S6+). Upon formation (at or immediately below the surface), the highly soluble cadmium sulfate is assumed to be transported to the surface in solution and reprecipitates there, forming the whitish globules. The presence of cadmium sulfate (CdSO4·2H2O) and ammonium cadmium sulfate [(NH4)2Cd(SO4)2] at the surface is confirmed by microscopic X-ray diffraction measurements, where the latter salt is suspected to result from a secondary reaction of cadmium sulfate with ammonia. Measurements performed on cross sections reveal that the oxidation front has penetrated into the yellow paint down to ca. 1−2 ìm. The morphology and elemental distribution of the paint and degradation product were examined by means of scanning electron microscopy equipped with an energy-dispersive spectrometer (SEM-EDS) and synchrotron radiation based micro-X-ray fluorescence spectrometry (SR ì-XRF). In addition, ultraviolet-induced visible fluorescence photography (UIVFP) revealed itself to be a straightforward technique for documenting the occurrence of this specific kind of degradation on a macroscale by painting conservators. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000264759400025 |
Publication Date |
2009-03-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.32 |
Times cited |
91 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 6.32; 2009 IF: 5.214 |
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Call Number |
UA @ admin @ c:irua:76415 |
Serial |
5501 |
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| Permanent link to this record |
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Author |
Cagno, S.; Brede, D.A.; Nuyts, G.; Vanmeert, F.; Pacureanu, A.; Tucoulou, R.; Cloetens, P.; Falkenberg, G.; Janssens, K.; Salbu, B.; Lind, O.C. |
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Title |
Combined computed nanotomography and nanoscopic x-ray fluorescence imaging of cobalt nanoparticles in caenorhabditis elegans |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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| |
Volume |
89 |
Issue |
21 |
Pages |
11435-11442 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Synchrotron radiation phase-contrast computed nanotomography (nano-CT) and two-and three-dimensional (2D and 3D) nanoscopic X-ray fluorescence (nano-XRF) were used to investigate the internal distribution of engineered-cobalt nanoparticles (Co NPs) in exposed individuals of the nematode Caenorhabditis elegans. Whole-nematodes and selected tissues and organs were 3D-rendered: anatomical 3D renderings with 50 nm voxel size enabled the visualization of spherical nanoparticle aggregates. with size tip to 200 nm within intact C. elegans. A 20 X 37 nm(2) high-brilliance beam was employed to obtain XRF elemental distribution maps of entire nematodes or anatomical details such as embryos, which could be compared with the CT data, These maps showed Co NPs to be predominantly present within the intestine and the epithelium, and they were not colocalized with Zn granules found in the lysosonie-containing vesicles or Fe agglomerates in the intestine. Iterated XRF scanning of a specimen at 0 degrees and 90 degrees angles suggested that NP aggregates were translocated into tissues outside of the intestinal lumen. Virtual-slicing by means of 2D XRF tomography, combined with holotomography, indicated presumable presence of individual NP aggregates inside the uterus and within embryos. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000414887000041 |
Publication Date |
2017-10-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
13 |
Open Access |
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Notes |
; This study has been funded by the Norwegian Research Council through its Centre of Excellence (CoE) funding scheme (Project 223268/F50). We gratefully acknowledge ESRF and DESY for granting beamtime and Karl Andreas Jensen for performing ICPMS analysis. We thank Erica Maremonti for supplying the phase-contrast image used in Figure ^1A. ; |
Approved |
Most recent IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:147383 |
Serial |
5520 |
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| Permanent link to this record |
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Author |
van der Snickt, G.; Janssens, K.; Dik, J.; de Nolf, W.; Vanmeert, F.; Jaroszewicz, J.; Cotte, M.; Falkenberg, G.; Van der Loeff, L. |
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Title |
Combined use of synchrotron radiation based micro-X-ray fluorescence, micro-X-ray diffraction, micro-X-ray absorption near-edge, and micro-fourier transform infrared spectroscopies for revealing an alternative degradation pathway of the pigment cadmium yellow in a painting by Van Gogh |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
84 |
Issue |
23 |
Pages |
10221-10228 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Over the past years a number of studies have described the instability of the pigment cadmium yellow (CdS). In a previous paper we have shown how cadmium sulfide on paintings by James Ensor oxidizes to CdSO4 center dot H2O. The degradation process gives rise to the fading of the bright yellow color and the formation of disfiguring white crystals that are present on the paint surface in approximately 50 mu m sized globular agglomerations. Here, we study cadmium yellow in the painting “Flowers in a blue vase” by Vincent van Gogh. This painting differs from the Ensor case in the fact that (a) a varnish was superimposed onto the degraded paint surface and (b) the CdS paint area is entirely covered with an opaque crust. The latter obscures the yellow color completely and thus presents a seemingly more advanced state of degradation. Analysis of a cross-sectioned and a crushed sample by combining scanning microscopic X-ray diffraction (mu-XRD), microscopic X-ray absorption near-edge spectroscopy (mu-XANES), microscopic X-ray fluorescence (mu-XRF) based chemical state mapping and scanning microscopic Fourier transform infrared (mu-FT-IR) spectrometry allowed unravelling the complex alteration pathway. Although no crystalline CdSO4 compounds were identified on the Van Gogh paint samples, we conclude that the observed degradation was initially caused by oxidation of the original CdS pigment, similar as for the previous Ensor case. However, due to the presence of an overlying varnish containing lead-based driers and oxalate ions, secondary reactions took place. In particular, it appears that upon the photoinduced oxidation of its sulfidic counterion, the Cd2+ ions reprecipitated at the paint/varnish interface after having formed a complex with oxalate ions that themselves are considered to be degradation products of the resin and/or oil in the varnish. The SO42- anions, for their part, found a suitable reaction partner in Pb2+ ions stemming from a dissolved lead-based siccative that was added to the varnish to promote its drying. The resulting opaque anglesite compound in the varnish, in combination with the underlying CdC2O4 layer at the paint/varnish interface, account for the orange-gray crust that is disfiguring the painting on a macroscopic level. In this way, the results presented in this paper demonstrate how, through a judicious combined use of several microanalytical methods with speciation capabilities, many new insights can be obtained from two minute, but highly complex and heterogeneous paint samples. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000311815300013 |
Publication Date |
2012-08-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
59 |
Open Access |
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Notes |
; This research was supported by BELSPO via the Interuniversity Attraction Poles Programme (IUAP VI/16) and the S2-ART project (SD/RI/04A) and funded by Grants from the ESRF (EC-442) and PETRA-III (I-20120312 EC). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) project nos. G.0103.04, G.0689.06, and G.0704.08. The staff of the Kroller-Muller Museum and painting conservators Margje Leeuwestein and Esther Van Duijn are acknowledged for this pleasant cooperation and the authorization for the publication of the images in this article. ; |
Approved |
Most recent IF: 6.32; 2012 IF: 5.695 |
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Call Number |
UA @ admin @ c:irua:105971 |
Serial |
5526 |
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| Permanent link to this record |
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Author |
Monico, L.; Janssens, K.; Miliani, C.; van der Snickt, G.; Brunetti, B.G.; Guidi, M.C.; Radepont, M.; Cotte, M. |
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Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : 4 : artificial aging of model samples of co-precipitates of lead chromate and lead sulfate |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
85 |
Issue |
2 |
Pages |
860-867 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
Previous investigations about the darkening of chrome yellow pigments revealed that this form of alteration is attributable to a reduction of the original Cr(VI) to Cr(III), and that the presence of sulfur-containing compounds, most often sulfates, plays a key role during this process. We recently demonstrated that different crystal forms of chrome yellow pigments (PbCrO4 and PbCr1xSxO4) are present in paintings by Vincent van Gogh. In the present work, we show how both the chemical composition and the crystalline structure of lead chromate-based pigments influence their stability. For this purpose, oil model samples made with in-house synthesized powders of PbCrO4 and PbCr1xSxO4 were artificially aged and characterized. We observed a profound darkening only for those paint models made with PbCr1xSxO4, rich in SO42 (x ≥ 0.4), and orthorhombic phases (>30 wt %). Cr and S K-edge micro X-ray absorption near edge structure investigations revealed in an unequivocal manner the formation of up to about 60% of Cr(III)-species in the outer layer of the most altered samples; conversely, independent of the paint models chemical composition, no change in the S-oxidation state was observed. Analyses employing UVvisible diffuse reflectance and Fourier transform infrared spectroscopy were performed on unaged and aged model samples in order to obtain additional information on the physicochemical changes induced by the aging treatment. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Language |
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Wos |
000313668400032 |
Publication Date |
2012-10-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
49 |
Open Access |
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Notes |
; This research was supported by grants from ESRF (experiment EC-799), the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16), and the BELSPO-SDD S2-ART (SD/RI/04) project. The text also presents results from GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and FWO (Brussels, Belgium) projects G.0704.08 and G.01769.09. The EU FP7 programme CHARISMA (Grant Agreement 228330) and MIUR (PRIN08, Materiali e sistemi innovativi per la conservazione dell'arte contemporanea 2008 FFXXN9) are also acknowledged. ; |
Approved |
Most recent IF: 6.32; 2013 IF: 5.825 |
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Call Number |
UA @ admin @ c:irua:110471 |
Serial |
5569 |
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| Permanent link to this record |
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Author |
Monico, L.; Janssens, K.; Vanmeert, F.; Cotte, M.; Brunetti, B.G.; van der Snickt, G.; Leeuwestein, M.; Plisson, J.S.; Menu, M.; Miliani, C. |
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Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : part 5 : effects of nonoriginal surface coatings into the nature and distribution of chromium and sulfur species in chrome yellow paints |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
86 |
Issue |
21 |
Pages |
10804-10811 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The darkening of lead chromate yellow pigments, caused by a reduction of the chromate ions to Cr(III) compounds, is known to affect the appearance of several paintings by Vincent van Gogh. In previous papers of this series, we demonstrated that the darkening is activated by light and depends on the chemical composition and crystalline structure of the pigments. In this work, the results of Part 2 are extended and complemented with a new study aimed at deepening the knowledge of the nature and distribution of Cr and S species at the interface between the chrome yellow paint and the nonoriginal coating layer. For this purpose, three microsamples from two varnished paintings by Van Gogh and a waxed low relief by Gauguin (all originally uncoated) have been examined. Because nonoriginal coatings are often present in artwork by Van Gogh and contemporaries, the understanding of whether or not their application has influenced the morphological and/or physicochemical properties of the chrome yellow paint underneath is relevant in view of the conservation of these masterpieces. In all the samples studied, microscopic X-ray fluorescence (mu-XRF) and X-ray absorption near edge structure (mu-XANES) investigations showed that Cr(III)-based alteration products are present in the form of grains inside the coating (generally enriched of S species) and also homogeneously widespread at the paint surface. The distribution of Cr(III) species may be explained by the mechanical friction caused by the coating application by brush that picked up and redistributed the superficial Cr compounds, likely already present in the reduced state as result of the photodegradation process. The analysis of the XANES profiles allowed us to obtain new insights into the nature of the Cr(III) alteration products, that were identified as sulfate-, oxide-, organo-metal-, and chloride-based compounds. Building upon the knowledge acquired through the examination of original paint samples and from the investigation of aged model paints in the last Part 4 paper, in this study we aim to characterize a possible relation between the chemical composition of the coating and the chrome yellow degradation pathways by studying photochemically aged model samples covered with a dammar varnish contaminated with sulfide and sulfate salts. Cr speciation results did not show any evidence of the active role of the varnish and added S species on the reduction process of chrome yellows. |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
000344510200043 |
Publication Date |
2014-10-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
25 |
Open Access |
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Notes |
; This research was supported by the Italian projects PRIN (SICH) and PON (ITACHA). The text also presents results from Interuniversity Attraction Poles Programme Belgian Science Policy (S2-ART project S4DA), GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. ESRF is acknowledged for the grants received (experiments EC-799 and EC-1051). L.M. acknowledges the CNR for the financial support received in the framework of the Short Term Mobility Programme 2013. Thanks are expressed to Ella Hendriks (Van Gogh Museum, Amsterdam) and Muriel Geldof (Cultural Heritage Agency of The Netherlands) for selecting and sharing the information on the cross-section taken from Bank of the Seine. All the staff of the Van Gogh Museum, the Kroller-Muller Museum, and the Musee d'Orsay are acknowledged for the agreeable cooperation. ; |
Approved |
Most recent IF: 6.32; 2014 IF: 5.636 |
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Call Number |
UA @ admin @ c:irua:122100 |
Serial |
5570 |
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| Permanent link to this record |
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Author |
Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Dik, J.; Radepont, M.; Hendriks, E.; Geldof, M.; Cotte, M. |
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Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 2 : original paint layer samples |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
83 |
Issue |
4 |
Pages |
1224-1231 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
The darkening of the original yellow areas painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is a phenomenon widely observed on several paintings by Vincent van Gogh, such as the famous different versions of Sunflowers. During our previous investigations on artificially aged model samples of lead chromate, we established for the first time that darkening of chrome yellow is caused by reduction of PbCrO4 to Cr2O3·2H2O (viridian green), likely accompanied by the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide]. In the second part of this work, in order to demonstrate that this reduction phenomenon effectively takes place in real paintings, we study original paint samples from two paintings of V. van Gogh. As with the model samples, in view of the thin superficial alteration layers that are present, high lateral resolution spectroscopic methods that make use of synchrotron radiation (SR), such as microscopic X-ray absorption near edge (μ-XANES) and X-ray fluorescence spectrometry (μ-XRF) were employed. Additionally, μ-Raman and mid-FTIR analyses were carried out to completely characterize the samples. On both paint microsamples, the local presence of reduced Cr was demonstrated by means of μ-XANES point measurements. The presence of Cr(III) was revealed in specific areas, in some cases correlated to the presence of Ba(sulfate) and/or to that of aluminum silicate compounds. |
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Wos |
000287176900012 |
Publication Date |
2011-02-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
84 |
Open Access |
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Notes |
; This research was funded by grants from ESRF (experiment EC-504) and by HASYLAB (experiments 11-20080130 EC and 11-20070157 EC) and was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) project nos. G.0103.04, G.0689.06, and G.0704.08. The staff of the Van Gogh Museum, Amsterdam, is acknowledged for their agreeable cooperation and for the authorization to publish the images of the paintings in this article. L.M. was financially supported by the Erasmus Placement in the framework of Lifelong Learning Programme (A.Y. 2009-2010). The EU Community's FP7 Research Infrastructures program under the CHARISMA Project (Grant Agreement 228330) is also acknowledged. ; |
Approved |
Most recent IF: 6.32; 2011 IF: 5.856 |
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Call Number |
UA @ admin @ c:irua:88795 |
Serial |
5571 |
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Author |
Anaf, W.; Trashin, S.; Schalm, O.; van Dorp, D.; Janssens, K.; De Wael, K. |
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Title |
Electrochemical photodegradation study of semiconductor pigments : influence of environmental parameters |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
86 |
Issue |
19 |
Pages |
9742-9748 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
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Abstract |
Chemical transformations in paintings often induce discolorations, disturbing the appearance of the image. For an appropriate conservation of such valuable and irreplaceable heritage objects, it is important to have a good know-how on the degradation processes of the (historical) materials: which pigments have been discolored, what are the responsible processes, and which (environmental) conditions have the highest impact on the pigment degradation and should be mitigated. Pigment degradation is already widely studied, either by analyzing historical samples or by accelerated weathering experiments on dummies. However, in historic samples several processes may have taken place, increasing the complexity of the current state, while aging experiments are time-consuming due to the often extended aging period. An alternative method is proposed for a fast monitoring of degradation processes of semiconductor pigments, using an electrochemical setup mimicking the real environment and allowing the identification of harmful environmental parameters for each pigment. Examples are given for the pigments cadmium yellow (CdS) and vermilion (α-HgS). |
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Wos |
000343017100058 |
Publication Date |
2014-08-27 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
18 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 6.32; 2014 IF: 5.636 |
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Call Number |
UA @ admin @ c:irua:118834 |
Serial |
5593 |
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Author |
Bulska, E.; Wysocka, I.A.; Wierzbicka, M.H.; Proost, K.; Janssens, K.; Falkenberg, G. |
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Title |
In vivo investigation of the distribution and the local speciation of selenium in Allium cepa L. by means of microscopic X-ray absorption near-edge structure spectroscopy and confocal microscopic X-ray fluorescence analysis |
Type |
A1 Journal article |
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Year |
2006 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
78 |
Issue |
22 |
Pages |
7616-7624 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000242021400003 |
Publication Date |
2006-10-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
56 |
Open Access |
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Notes |
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Approved |
Most recent IF: 6.32; 2006 IF: 5.646 |
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Call Number |
UA @ admin @ c:irua:60714 |
Serial |
5659 |
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Author |
Vanmeert, F.; de Nolf, W.; De Meyer, S.; Dik, J.; Janssens, K. |
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Title |
Macroscopic X-ray powder diffraction scanning, a new method for highly selective chemical imaging of works of art : instrument optimization |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
90 |
Issue |
11 |
Pages |
6436-6444 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
In the past decade macroscopic X-ray fluorescence imaging (MA-XRF) has become established as a method for the noninvasive investigation of flat painted surfaces, yielding large scale elemental maps. MA-XRF is limited by a lack of specificity, only allowing for indirect pigment identification based on the simultaneous presence of chemical elements. The high specificity of X-ray powder diffraction (XRPD) mapping is already being exploited at synchrotron facilities for investigations at the (sub)microscopic scale, but the technique has not yet been employed using lab sources. In this paper we present the development of a novel MA-XRPD/XRF instrument based on a laboratory X-ray source. Several combinations of X-ray sources and area detectors are evaluated in terms of their spatial and angular resolution and their sensitivity. The highly specific imaging capability of the combined MA-XRPD/XRF instrument is demonstrated on a 15th/16th century illuminated manuscript directly revealing the distribution of a large number of inorganic pigments, including the uncommon yellow pigment massicot (o-PbO). The case study illustrates the wealth of new mapping information that can be obtained in a noninvasive manner using the laboratory MA-XRPD/XRF instrument. |
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Wos |
000434893200019 |
Publication Date |
2018-04-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
11 |
Open Access |
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Notes |
; The authors thank the persons involved at Incoatec GmbH, imXPAD SAS and Dectris Ltd. for loaning us some of their products over the past years. We acknowledge financial support from BELSPO (Brussels) S2-ART, the NWO (The Hague) Science4Arts “ReVisRembrandt” Project and GOA Project Solarpaint (University of Antwerp Research Council). Photo Copyright Geert Van der Snickt, 2008 for the photograph of the illuminated manuscript in the TOC graphic. ; |
Approved |
Most recent IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:151993 |
Serial |
5701 |
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Author |
Vanmeert, F.; de Nolf, W.; Dik, J.; Janssens, K. |
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Title |
Macroscopic X-ray powder diffraction scanning : possibilities for quantitative and depth-selective parchment analysis |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
90 |
Issue |
11 |
Pages |
6445-6452 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
At or below the surface of painted works of art, valuable information is present that provides insights into an objects past, such as the artists technique and the creative process that was followed or its conservation history but also on its current state of preservation. Various noninvasive techniques have been developed over the past 2 decades that can probe this information either locally (via point analysis) or on a macroscopic scale (e.g., full-field imaging and raster scanning). Recently macroscopic X-ray powder diffraction (MA-XRPD) mapping using laboratory X-ray sources was developed. This method can visualize highly specific chemical distributions at the macroscale (dm(2)). In this work we demonstrate the synergy between the quantitative aspects of powder diffraction and the noninvasive scanning capability of MA-XRPD highlighting the potential of the method to reveal new types of information. Quantitative data derived from a 15th/16th century illuminated sheet of parchment revealed three lead white pigments with different hydrocerussite-cerussite compositions in specific pictorial elements, while quantification analysis of impurities in the blue azurite pigment revealed two distinct azurite types: one rich in barite and one in quartz. Furthermore, on the same artifact, the depth-selective possibilities of the method that stem from an exploitation of the shift of the measured diffraction peaks with respect to reference data are highlighted. The influence of different experimental parameters on the depth-selective analysis results is briefly discussed. Promising stratigraphic information could be obtained, even though the analysis is hampered by not completely understood variations in the unit cell dimensions of the crystalline pigment phases. |
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Corporate Author |
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Place of Publication |
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Wos |
000434893200020 |
Publication Date |
2018-04-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
6 |
Open Access |
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Notes |
; The authors thank Incoatec GmbH for giving us the opportunity to test the I mu S Cu X-ray source. We acknowledge financial support from BELSPO (Brussels) S2-ART, the NWO (The Hague) Science4Arts “ReVisRembrandt” project, and GOA Project Solarpaint (University of Antwerp Research Council). Photo Copyright Geert Van der Snickt, 2008 for the photograph of the illuminated manuscript in the TOC graphic. ; |
Approved |
Most recent IF: 6.32 |
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Call Number |
UA @ admin @ c:irua:151994 |
Serial |
5702 |
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Author |
Kempenaers, L.; Janssens, K.; Vincze, L.; Vekemans, B.; Somogyi, A.; Drakopoulos, M.; Simionovici, A.S.; Adams, F. |
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Title |
A Monte Carlo model for studying the microheterogeneity of trace elements in reference materials by means of synchrotron microscopic X-ray fluorescence |
Type |
A1 Journal article |
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Year |
2002 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
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Volume |
74 |
Issue |
19 |
Pages |
5017-5026 |
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Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Abstract |
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Thesis |
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Place of Publication |
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Wos |
000178418100031 |
Publication Date |
2002-09-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
6.32 |
Times cited |
21 |
Open Access |
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Notes |
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Approved |
Most recent IF: 6.32; 2002 IF: 5.094 |
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Call Number |
UA @ admin @ c:irua:39871 |
Serial |
5734 |
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| Permanent link to this record |
