Surface chemical reactions in Paintings Katrien Keune Rijksmuseum Amsterdam and University of Amsterdam, The Netherlands
#Umeet #uva #wvdw 2
#Umeet #uva #wvdw 3
#Umeet #uva #wvdw 4
Preferred appearance? 5
2 3 1 Vincent van Gogh s Bedroom (1888; canvas 72 x 90 cm), Van Gogh Museum, Amsterdam Research: E. Hendricks et al.; Van Gogh Museum, Cultural Heritage Agency of the Netherlands (RCE) and Netherlands Organization for Scientific Research (NWO) in cooperation with Prof. R. S. Berns, Munsell Color Science Laboratory.
Paint sample research paint cross-sections 20 μm Macroscopic detail of De Dorser, Van Gogh (1889), Van Gogh museum Paint cross-section Image: L.Carlyle Light microscopic image under UV Sample from De Dorser, Van Gogh (1889), Van Gogh museum
Realgar (AsS) and Orpiment (As 2 S 3 ) Still life with five apricots, Adriaen de Coorte, 1704, Royal Picture Gallery Mauritshuis, The Hague
Realgar (AsS) and Orpiment (As 2 S 3 ) - photodegradation paint layer 2? 1 paint layer paint layer 1? AsS As 2 O 3 Ground layer FeAsO + Ca 3 (AsO 4 ) 2 As-XANES at SSRL Image segmentation based on PCA Arsenic Phases Photodegradation products: AsO 3, AsO 5
Zinc Oxide (ZnO) Couple with Clouds in their Heads, Salvador DalÍ, 1936, Museum Boijmans van Beuningen
Zinc Oxide (ZnO)
Zinc Oxide (ZnO) intact paint degraded paint ZnO + 2RCOOH Zn(RCOO) 2 + H 2 O (R = C 15 H 31 /C 17 H 33 )
Zinc Oxide (ZnO) Photo shoot of Dalí and Gala taken by Cecil Beaton (1936)
After treatment: visually acceptable
Lead white pigments Still life with Asparagus, Adriaen Coorte, 17 e C, oil on paper on panel, Rijksmuseum PbO + 2RCOOH Pb(RCOO) 2 + H 2 O (R = C 15 H 31 /C 17 H 33 )
Lead pigments + fatty acids --> lead soaps PbO + 2RCOOH Pb(RCOO) 2 + H 2 O (R = C 15 H 31 /C 17 H 33 )
Ultramarine disease Restoration by Annetje Boersma, Rotterdam Van Eyck, The Three Marys at the Tomb, c.1425-35, oil on oak panel, Museum Boijmans Van Beuningen, Rotterdam
Macroscopic imaging X-ray fluorescence Macro-XRF scanner prof. J. Dik, TUDelft and profs. G. Van der Snickt en K. Janssens, University Antwerp
Macroscopic imaging X-ray fluorescence Lead (L-line) Copper (K-line) Potassium (K-line) XRF elemental macro maps
Correlating macro- and microscopic imaging Potassium Copper Lead
Ultramarine traditional separation method Lapis lazuli power Resin Beeswax Linseed oil Precious stone: Lapis Lazuli Containing the mineral Lazurite; (Na,Ca) 8 [(S,Cl,SO 4,OH) 2 (Al 6 Si 6 O 24 )] S 3 - chromophore Kneeded in water or lye solution
Intensity, arb. units Intensity, arb. units Intensity, arb. units Intensity, arb. units Preliminary results S-XANES No heat 415 C 600 C 750 C = S 3 radical contributions Energy, kev Energy, kev Energy, kev Energy, kev
Sunflowers by Van Gogh Sunflowers, (January 1889), Vincent van Gogh (1853-1890) Oil on canvas, 95 cm x 73 cm, Van Gogh Museum, Amsterdam
Sunflowers by Van Gogh Primrose Chrome (PbCr 1-x S x O 4, 0.45 x 0.55, orthorhombic) Lemon Chrome (PbCr 1-x S x O 4, 0.2 x 0.4) Middle Chrome (mainly pure PbCrO 4, monoclinic). Paint is: - Crumbly - Sensitive to solvents Internal porosity? Microscopic image, normal Microscopic image, UV Backscatter electron image
3-D Backscatter image: in-situ microtoming Beam Stage Zeiss Sigma with Gatan 3View system Centre for Microscopy and Microanalysis, University of Queensland, Australia
Example of 3D Backscatter image of paint cross-section In situ microtoming Sections of 60 nm BSE images at 2 kev 500 slices 50 x 50 μm Contrast inverted! Paint sample from Winding the skein by Leighton (1878) Queensland Art Gallery, Australia
3-D Backscatter image of paint cross-section Sections of 50 nm BSE images at 1.3 kev 200 slices 38.8 x 38.8 μm Voxel size: 9.7 x 9.7 x 50 nm
Image Segmentation PbCrO 4 Porous Binding medium Unknown 7.8 µm 38.8 µm 9 µm 38.8 µm Data processing and image segmentation (Avizo/Matlab): Florian Meirer
Image Segmentation - Quantification Total analyzed volume: 13474 µm 3 PbCrO 4 Porous Binding medium Unknown Volume fractions 33.82 % 0.34 % 65.66 % 0.24 % 78 %wt 22 %wt According to literature 1 75-80 %wt 20-25 %wt According to analyses of tube paints from 19 th C (Berthaut) 2 72 %wt 28 %wt 1. H. Kühn, M. Curran, Artists Pigments, vol. 1, Cambridge University Press, London 1986, p. 191 2. J. Salvant, Doctoral Thesis, Pierre-and-Marie-Curie University, 2012, p. 130
Porosity Porosity: 0.00342 at the macro/meso-pore scale diffusion is not possible 38.8 µm 38.8 µm 3% 11% 9% 9 µm 77%
NICAS