| Abstract [eng] |
Various methods of spectral analysis are used to identify the constituents of hictorial heritage objects. This information allows restorers to choose the appropriate conservation conditions and restoration methods. In case of damage to the gruond layer, the aim is to stabilize and restore it, so the restoration gruond is being prepared. In preparing this gruond, specialists evaluate the results of technological research. The anhydrite and its mixtures with dihydric gypsum is widely used as ground layer fillers in icon paintings. The properties of different types of anhydrite differ, so accurate determination of anhydrite burning temperatures is particularly important information when preparing a restorative ground. The subcategories of beta anhydrite are determined from the width of the Raman scattering spectral bands, but in this work the determination of anhydrite burning temperatures from the temperature dependences of the FT-IR ATR spectral bands is demonstrated for the first time. The objects of this research are four 19th century icons under the restoration process: "St. Simon and St. Nicholas", "Lord Almighty" "Mother of God" and the icon "Mother of God" belonging to a private collection. The aim of this work is to perform spectral analysis of the gruond layer of icons using vibrational spectroscopy methods. To achieve this goal, the following tasks have been set: 1. To record the FT-IR ATR spectra of different concentrations of dihydrate gypsum and anhydrite mixtures in the region of asymmetric deformation SO4 oscillations and to determine the concentration dependences of the intensity of these bands. 2. Record the FT-IR ATR spectra of anhydrite samples ignited at different temperatures (400–900 ° C) in the region of asymmetric deformation SO4 oscillations and determine the temperature dependences of the width of these oscillation bands. 3. To determine the binders used in the iconic gruond layer from the FT-IR ATR and Raman scattering spectra of the icon samples. 4. From the concentration and temperature dependences of the vibrational spectra of DG and AH, determine the composition of the ground layer of the four icon samples and the burning temperature of the anhydrite used in the filler. The vibrational spectra of the icons ground layers were recorded and the binding medium of ground layer was determened. In all icons binging medium was protein origin glue. It was determened that from integral intensity dependences of the vibrational bands corresponding to the asymmetric deformation valence vibrations of SO4 from the gypsum and anhydrite mixture you can determie the concentration. The FT-IR ATR spectra of the samples of pure anhydrite II burned from 400 ° C to 900 ° C were recorded and the temperature dependences of the SO4 oscillation band were determined. For the first time, the FT-IR ATR method was applied to determine the burning temperature of anhydrite used in icon ground layer. From the results of the research carried out in this work, it can be stated that not only Raman spectroscopy but also FT-IR ATR method can be used to determine the burning temperature of anhydrite II. |
