Efficiency of applying ammonium oxalate for protection of monumental limestone by poultice, immersion and brushing methods
- 255 Downloads
Samples of cretaceous limestone have been treated with three application methods (poultice, immersion and brushing) using different concentrations of ammonium oxalate solution (AmOx) and varying treatment time in order to test the efficiency of surface and in-depth formation of a protective layer of calcium oxalate (CaOx). Synchrotron-based microanalytical techniques (SR-μXRD with 12.5 μm×7.5 μm (H×V) probe size, SR-μFTIR with 10 μm×10 μm and 8 μm×20 μm probe sizes) and laboratory μFTIR, XRD and SEM have been employed for analysis of the treated samples. Synchrotron-based techniques showed variations in the CaOx distribution along the surface on a micrometer scale. All treatments resulted in the development of a CaOx layer with a maximum thickness of approximately 40 μm. Application by the brushing method with 10 1-min applications with 5-min breaks during one hour showed a development of the calcium oxalate layer equivalent to the poultice treatment taking 10 h. This treatment could be preferred for large marble or limestone surfaces where poultice usage is economically not feasible.
KeywordsOxalate Calcium Oxalate Ammonium Oxalate Stone Surface AmOx
We would like to thank Dr. Paul Dumas from the SMIS beamline at the ‘SOLEIL’ synchrotron in Saint-Aubin (France) for his help in the statistical analysis of the IR maps. Also, we would like to thank Dr. Cristian Mocuta from the DIFFABS beamline at the ‘SOLEIL’ synchrotron for his great help during the XRD depth measurements. We also appreciate the help of Dr. Philippe Lerch from the IR beamline at the ‘Swiss Light Source synchrotron, Paul Scherrer Institute’ in Villigen (Switzerland) during the surface IR measurements.
This research 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.0704.08 and G.01769.09.
The research leading to these results has received financial support by the Access to Research Infrastructures activity in the 7th Framework Programme of the EU (CHARISMA Grant Agreement No. 228330).
- 1.E. Hansen, E. Doehne, J. Fidler, J. Larson, B. Martin, M. Matteini, C. Rodríguez-Navarro, E.S. Pardo, C. Price, A. De Tagle, J.M. Teutonico, N. Weiss, Rev. Conserv. 4, 13 (2003) Google Scholar
- 2.V. Fassina, Proceedings, Le Pellicole Ad Ossalati Origine e Significato nella Conservazione delle Opere D’Arte (Centro ‘Gino Bozza’, Milano, 1989), p. 381 Google Scholar
- 3.M. Realini, L. Toniolo, International Symposium II: The Oxalate Films in the Conservation of Works of Art (Editeam, Castello D’Argile, 1996), p. 539 Google Scholar
- 4.K. Kouzeli, N. Beloyannis, C. Tolias, Y. Dogani, in Le Pellicole Ad Ossalati Origine e Significato nella Conservazione delle Opere D’Arte, ed. by V. Fassina (Centro ‘Gino Bozza’, Milano, 1989), pp. 327–336 Google Scholar
- 6.M. Matteini, Conserv. Sci. Cult. Herit. 8, 13 (2008) Google Scholar
- 8.M. Matteini, A. Moles, in Le Pitture Murali: Techniche, Problemi, Conservazione, ed. by A. Moles (Centro Di, Florence, 1990), pp. 297–302 Google Scholar
- 9.M. Matteini, A. Moles, S. Giovannoni, in Proceedings of the 3rd International Symposium: The Conservation of Monuments in the Mediterranean Basin: Stone and Monuments: Methodologies for the Analyses of Weathering and Conservation, ed. by V. Fassina, H. Ott, F. Zezza (Soprintendenza ai Beni Artistici e Storici di Venizia, Venice, 1994), pp. 155–162 Google Scholar
- 10.M. Matteini, A. Moles, G. Lanterna, M.R. Nepoti, in International Symposium II: The Oxalate Films in the Conservation of Works of Art, ed. by M. Realini, L. Toniolo (Editeam, Castellio D’Argile, 1996), pp. 425–440 Google Scholar
- 11.M. Ambrosi, P. Baglioni, P.R. David, L. Dei, R. Giorgi, C. Lalli, A. Mairani, M. Matteini, M. Rizzi, G. Schonhaut, G. Lanterna, in Proceedings, Science and Technology for the Safeguard of Cultural Heritage in the Mediterranean Basin, ed. by A. Guarino (Elsevier, Paris, 2000), pp. 855–858 Google Scholar
- 12.A. Mairani, M. Matteini, M. Rizzi, OPD, Restauro 12, 146 (2000) Google Scholar
- 15.X’Pert HighScore Plus (PANalytical B.V., Almelo, 2004) Google Scholar
- 16.ICDD—International Centre for Diffraction Data, in Powder Diffraction File PDF-2 (ICDD, Newtown Square, PA, 2004) Google Scholar
- 17.http://www.cytospec.com; CytoSpec ver. 1.2, CytoSpec, Inc., USA (2005)