Degradation Products Assessment of the Wooden Painted Surfaces from a XVIIth Heritage Monastery

Abstract

Currently, approximately 70% of paintings in museum collections are affected by the presence of metallic soaps, evidenced by spherical globules visible on the surface of the paintings. They are responsible for altering the paintings’ surface through processes such as exfoliation and cracking, or even in the form of surface “skins” that appear in the pictorial layers. The objective of this study is the investigation of the icon paintings from Saint Mary Monastery, Techirghiol, Romania, which underwent some restoration procedures. This study is so important/significant, due to the presence of efflorescence that is correlated with the conversion of some fatty acids, as palmitic acid, stearic acid and azelaic acid, in the so-called metallic soaps through the reaction of the metals contained in the pigments from the painting layer and the binder. The investigated paintings are strongly affected by zinc carboxylate aggregation, and for this, the sample was embedded in polyester resin and the obtained cross-section, after polishing, was investigated by microscopic techniques (optical microscopy (OM), stereomicroscopy, and scanning electron microscopy with electronic dispersion spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and gas-chromatography with mass spectrometry (GC-MS) in good agreement with data from the literature. The potential result of this study is the identification and quantification of the metallic soap generated as a white deposit (probably salts, a kind of white efflorescence), from the binding medium of the metal carboxylate ionomer, by the crystallization of saturated fatty acids, through polymerization in oil. Six pigments (calcite, lithopone, carbon black, red ochre, vermilion, and ultramarine), present in the sublayers of the samples were identified.

Assessment of color and contact angle changes in waterborne stained wood under natural weathering condition of South Korea’s summer climate

“…The values of ∆E, CN, A, and CN + A were less than 17, suggesting a low resistance to color change when compared to the control (21.62). The results are consistent with the findings of Ion et al (2023), who observed that weathered wood surfaces developed green or gray-blue spots, in turn, causing wood to turn gray. Moreover, the lowest decrease in L* and the lowest ∆E were observed in wood coated with CN stain.…”

“…The weathering of uncoated wood is usually associated with biological attack, such as mold and rot, which in turn, change the appearance of wood surfaces (Poohphajai et al 2021). The surfaces of weathered wood products eventually develop green or gray-blue spots and wood turns gray (Ion et al 2023).…”

Archaeometric Investigations of the Chalcolithic Pottery from Topolița—Neamț County, Romania

“…In the case investigated by us, no gahlenite-type compounds were identified by XRD; therefore, the calcite present here is silicate-free, and the upper limit of calcite decomposition is in the range of 600-800 °C [21]. It is important to note that the investigated samples are completely heterogeneous, and the nomenclature of the identified minerals complies with the IMA-CNMNC approved list [16]. Quartz and berlinite were identified, followed by hematite, anorthite, sodalite, scorzalite, albite, apatite, muscovite, mica, feldspar, crotite, TiO 2 , and graphite (Figure 2).…”

“…Intensity distribution maps show the presence of calcium and small amounts of elements Al, Na, K, Si, Ti, and Fe, which may indicate the presence of minerals rich in these elements, such as silicates, calcite, K-feldspar, hematite, etc. [16].…”

New Materials and Advanced Procedures of Conservation Ancient Artifacts

“…In the first article [1], the authors studied a series of icons from the Monastery of Saint Mary, Techirghiol, Romania, which underwent some inappropriate restoration procedures, namely aggressive cleaning with metallic soaps that affected the pigments and binders based on egg and walnut oil. The microsamples of pictorial material were investigated by microscopic techniques (OM and SEM-EDX), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, wavelength-dispersive X-ray fluorescence spectroscopy (WDXRF) and gas-chromatography with mass spectrometry (GC-MS).…”