The present study is concerned with the assessment of the relative resistance of a monumental dolomitic limestone (Laspra – Spain) used as building material in stone monuments and submitted to artificial ageing by SO2 dry deposition in the presence of humidity. To investigate the protection efficiency of different polymeric coatings, three commercially available siloxane-based oligomers (Lotexan-N, Silres BS 290 and Tegosivin HL 100) and a newly synthesized hybrid nanocomposite with silsesquioxane units (TMSPMA) were used. A comparative assessment of the data obtained in this study underlines that a better limestone protection was obtained when treated with the hybrid nanocomposite with silsesquioxane units.

No abstract

No abstract

The paper focuses on two works of art, Chrysanthemums and Roses, painted by Stefan Luchian, a representative painter for the modern Romanian art from the beginning of the 20th century. The two paintings were analyzed by several non-invasive techniques (optical microscopy, grazing light and UV examination, IR reflectography, XRF and Raman spectrometry) in order to get information concerning the chromatic and to assess the state of conservation. The study is focused in particular on yellow, red and white pigments, which are different in the two pictorial compositions: in Chrysanthemums the predominant pigments are Madder lake, cadmium yellow and zinc white mixed with lead white, while in Roses cinnabar, strontium yellow and lead white were found, according to the XRF and Raman analysis.

Paintings signed by Nicolae Grigorescu and Stefan Luchian, exponents of Romanian Modern Art were selected for a technical study on easel painting canvases. Both the physical integrity and the appearance of the artefacts derive mainly from the strength of the canvas and the physical and chemical characteristics of the fibres imparting their response to deterioration. In order to determine a deterioration pattern for canvases subjected to environmental stress, a simulation on flax fibres samples was performed using a climatic lab chamber. Structural changes of lignocellulosic materials were monitored by attenuated total reflectance infrared (ATR-FTIR) and FT-Raman spectroscopy. Changes in the intensity of FT-Raman signals of flax fibres indicate the evolution of the degradation phenomena due to environmental stress.