Agenda

11 Mar 2019 12:15

A New Perspective on the Phenomenon of "Ultramarine Disease" in Paintings

Campus Scientifico via Torino - edificio ZETA, Aula A

dr. E.R. de la Rie, University of Amsterdam, Centre de Recherche sur la Conservation des Collections, Paris

Abstract:
Failure of ultramarine blue paint layers in historic as well as modern paintings has been reported in the literature many times and is often referred to as “ultramarine disease” or “ultramarine sickness.” The pigment itself is known to degrade hydrolytically when exposed to acids, but whether this is the primary cause of the failure remains unclear. A study at CRCC in collaboration with the University of Amsterdam, Pratt Institute in New York and the Technical University of Delft focused on ultramarine blue paints using linseed oil and a urea-aldehyde resin as binding media. The paints, prepared by Gambin Artist Colors, were aged under simulated indoor conditions.The paints were analyzed using reflectance spectroscopy, scanning electron microscopy, and Raman and nuclear magnetic resonance spectroscopy. The urea-aldehyde resin binding medium was analyzed using size exclusion chromatography and Fourier-transform infrared spectroscopy. The study provides evidence of photo-catalytic degradation of binding media of ultramarine blue paint layers via free-radical processes, causing changes in reflectance while the pigment itself remains intact. It is believed that this is the primary process behind the degradation of ultramarine blue paint layers in paintings.
Ultramarine blue has a zeolite structure and the results are in agreement with the photo-catalytic activity of other zeolites. The sulfur radical anion color centers trapped in the zeolite cage do not appear to play a role in the process and the cage itself remains intact. The free radical process can be inhibited with a hindered amine light stabilizer.

Bio Sketch:

  • University of Amsterdam Guest Researcher 2012-present
  • Centre de Recherche sur la Conservation des Collections, Paris Chercheur Associée 2012-present
  • National Gallery of Art, Washington, DC Head, Scientific Research 1989-2012 (Chair endowed by the Andrew W. Mellon Foundation) Development and testing of conservation materials and methods; study of degradation processes; characterization of historic and artists' methods and materials; methods include XRF, XRD, SEM/EDS, Py-GCMS, LCMS, SEC, FTIR, accelerated aging, reflectance and luminescence (imaging) spectroscopy, polarized light microscopy, microchemical analysis; management of budget; writing of grant proposals, hiring and supervision of staff and postdoctoral fellows (http://www.nga.gov/resources/scienceresearch/conservationpublist.shtm).
  • University of Amsterdam, Faculty of Science Adjunct Professor (Bijzonder Hoogleraar) of Conservation Science 1994-2004
  • International Institute for Conservation of Historic & Artistic Works (IIC) Editor of the journal Studies in Conservation 1994-2011
  • Royal Netherlands Academy of Science Correspondent 1992-present
  • Metropolitan Museum of Art, New York, NY Research Chemist 1981-89 In charge of scientific research and analytical studies
  • New York University Adjunct Professor of Conservation 1988-90 Adjunct Associate Professor of Conservation 1983-88 Training Program for Conservators, Amsterdam, The Netherlands Staff Docent and Assistant Administrator 1978-81

Lingua

L'evento si terrà in italiano

Organizzatore

Elisabetta Zendri, Dafne Cimino

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