Stamatis Boyatzis

Zinc oxide (ZnO) nanoparticles have attracted increasing attention in wood science due to their multifunctional properties, including antimicrobial activity, UV absorption, and photocatalytic behavior. Water-based deposition protocols offer clear advantages yet typically struggle with nanoparticle aggregation and limited adhesion to lignocellulosic substrates. This work introduces a rapid and scalable waterborne protocol combining catalyst-free aqueous seeding with microwave-assisted (MWA) growth under mild conditions. Pinus pinaster veneer samples were treated via dip-coating and spraying, with single and double seeding cycles, followed by MWA growth. Protocol efficiency was assessed through ZnO retention, SEM, and EDS analysis, while the impact of the substrate was assessed via mechanical testing, ATR-FTIR spectroscopy, and colorimetry. Dip-coating achieves significantly higher precursor uptake than spraying, while repeated seeding cycles further increase ZnO loading. Results suggest that incorporation may proceed through zinc–carboxylate bonds within the wood matrix, followed by localized ZnO nanostructures development. The effective integration did not weaken the mechanical properties, while color changes were significant for dip-coated samples and noticeable for sprayed ones. Overall, this methodology provides a fast, water-based, and minimally invasive route for ZnO incorporation into wood and a scalable pathway with retained mechanical and chemical properties and limited visual impact.

Replication of brown-rotted wood is essential for researchers across disciplines who require suitable and reliable substrates for laboratory experiments. While enzymatic protocols are commonly used, their inherent heterogeneity limits reproducibility and compromises replicate consistency. As a result, researchers are turning to non-enzymatic protocols, particularly the Chelator-Mediated Fenton (CMF) reaction. Although these protocols are successful, they are typically evaluated based solely on the chemical properties of decayed wood, while other key properties remain largely unexamined. This study therefore aimed to examine the physical and mechanical properties of CMF-treated wood, alongside its chemistry, to evaluate its suitability as a reliable substrate for laboratory studies. Scots pine ( Pinus sylvestris L.) samples were CMF-treated and analyzed chemically by ATR-FTIR spectroscopy, mechanically through Shore D hardness and micro three-point static bending tests, and physically by measuring equilibrium moisture content, apparent density, mass loss, and color. For comparison, samples decayed by the brown rot fungus Coniophora puteana were also examined. Results showed that CMF-treated samples closely mimic fungal decay, exhibiting selective polysaccharide depolymerization, pronounced mechanical strength loss, and distinctive physical and morphological changes. These findings demonstrate that non-enzymatic decay protocols can reliably replicate the physicochemical and mechanical properties of brown-rotted wood, offering consistent substrates for experimental research.

Ethnographic collections often incorporate composite objects consisting of various materials, including wood, textiles and metals. These objects are vulnerable to deterioration when iron fastenings corrode under humid environments, and their removal is therefore essential for the long-term preservation of artifacts. This study investigates the efficacy of the chelating agents Desferrioxamine B (DFO-B) and ethylenediaminetetraacetic acid (EDTA), applied in different gel formulations, in cleaning wooden and textile mock-ups stained with iron corrosion products. Three gel types were explored: xanthan gum, agarose and Nanorestore extra-dry gel with medium water retention (nano-MWR). The results indicated that xanthan gum exhibited the highest cleaning effectiveness but posed risks of residue deposition and surface damage due to the required clearance process. Agarose and nano-MWR gels proved to be less effective but showed potential for achieving high chelator efficacy with repeated applications. Agarose enhanced the chelators’ efficacy on textiles, while nano-MWR gel performed better on even wooden surfaces. No chemical damage was detected for either substrate across gel applications. The study concludes that a single gel formulation does not achieve equivalent cleaning efficacy on the two substrates of composite objects with a defined number of applications. Agarose in a semi-rigid state enhances the efficacy of textile treatment and may achieve comparable results on wood after repeated applications. Alternatively, a combined approach using agarose for textiles and nano-MWR gel for wood may optimize chelator performance on composite artifacts.

Folk art includes objects that are items for everyday use and, at the same time, gracefully reflect the Greek artistic point of view, drawing its inspiration from life itself, the environment and its beauties, and local tradition. An 18th c. wood-carved and painted chest coming from the famous wood-carved centers of Epirus in Greece is presented in this study. As the number of studies and the general bibliographical references are limited for these kinds of items, prior to interventive conservation, a protocol of analysis was followed to identify the damages, the construction materials, and previous alterations. The main goal of this study is to identify the component materials using non-destructive techniques. The methodology followed for the documentation of the artifact includes the following: a. digital microscopy to identify damage from insects, different cracks and losses on the gesso and paint surface, corrosion products, etc.; b. 3D imaging using a polycam, with special attention given to the inside decoration of the cap; c. IR and UV photography to identify any previous alterations or signs of alterations in the varnish layers; d. and XRF analysis to identify the three (3) main colors of the chest, such as the blue used extensively as a background, red, and white. Nevertheless, the Greek folklore painting palette is limited, and for this reason, this study can be a foundation for research on similar artifacts.

Among the materials constituting our cultural heritage, parchment has a significant role as the substrate of many archival documents. The assessment of its state of preservation has an important benefit to conservation and delineates the adequate preventive measures that would lead to better‐controlled storage and exhibition conditions in museums and libraries worldwide. In the framework of this project, artificial aging of 48 new goat parchment samples was performed to induce deterioration similar to naturally aged parchment exposed to atmospheric pollutants. Five factors have been examined: relative humidity; NO₂; SO₂; exposure time, and the order of sequential exposure to NO₂ and SO₂. Temperature was kept constant at 25°C, while the effect of the above‐mentioned factors was examined at two levels (low and high). Statistics was involved in advance in the experimental design. Raman spectroscopy along with attenuated total reflectance‐Fourier transform infrared (ATR‐FTIR) spectroscopy were used to investigate the condition of collagen in parchment. The entire set of environmental factors along with detected changes in the spectra were investigated through a chemometrics scheme involving analysis of variance (ANOVA). According to the results, the onset of collagen's secondary structure decomposition was observed. Statistical elaboration of data reveals that the two analytical methods (Raman and ATR‐FTIR) function in a complementary manner related to the molecular changes and the chemical reactions that happen. In conclusion, both methods can increase their impact on the investigation of parchment degradation if they are combined with other analytical methods and chemometric applications.

The present work investigates the physicochemical stability of spray paints when irradiated with artificial solar light (at spectral range 300–800 nm). This research highlights the importance of understanding the materials used in street art and public murals, recognising them as a significant component of contemporary cultural heritage. By examining the stability and degradation of spray paints toward solar light exposure, the study aims to contribute to the preservation of contemporary murals, which reflect current social and cultural narratives. A physicochemical approach was employed for the study of spray paints’ physical and thermal properties, as well as the effect of specific photochemical ageing reactions/processes. The photochemical ageing results were compared with reference (unaged) samples. Specifically, a multi-technique approach was applied using stereo microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurement, colorimetry, glossimetry, differential scanning calorimetry (DSC), UV-Vis spectroscopy, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and pyrolysis-GC/MS (Py-GC/MS). The photodegradation of the spray paints occurred from the first 144 h of solar light irradiation, resulting in changes in morphology, colour, gloss, roughness, and wettability. Regarding photochemical stability, ageing seems to affect the binders more than the synthetic organic pigments and the inorganic fillers. In particular, acrylic binders showed small chemical changes, whereas the alkyd, nitrocellulose, and styrene binders underwent severe chemical modification. The results suggest that simulated daylight irradiation prompts the migration of additives toward the surface of the spray paint films. In addition, the results of the analyses on the white spray paints in comparison with the coloured paints (from the same manufacturer) showed that there seems to be an active distinct photoageing mechanism involving titanium dioxide, but the whole issue needs further investigation.

The reactivities of various fatty monoacids and diacids on copper metal-containing surfaces were investigated through reflection–absorption infrared spectroscopy. The formation of copper carboxylates is detected on pure copper surfaces, while copper and zinc carboxylates are simultaneously formed on brass surfaces. Following the decrease of acid carbonyl and the formation of carboxylate infrared bands, it is shown that fatty monoacids C8 and C10 react with clean/polished copper and its zinc alloy within 2–4 h, while those with chains > C12 react within days. At the end of the processes, only the corresponding metal carboxylates are detected in all cases. An explanation for the above is offered on a molecular mobility and acidity basis, where the lower monoacids (liquids in room temperature), also having lower pK_a values, favor higher reaction rates. Furthermore, it is argued that longer-chain fatty monoacids, when deposited from their solutions, allow for favorable orientation resulting in self-assembled monolayer-type molecular packing on the copper surface, which may additionally rationalize the slower reaction. Interestingly, fatty diacids do not form any carboxylate products under the same conditions, as it is argued that their molecules may efficiently pack as self-assembled multilayers on copper and ultimately protect it. The possible implications of the fatty monoacid and diacid behavior on the archaeological organic residues level and regarding the stability of copper alloys are discussed.

Previous works of the authors have presented the changes in the optical, mechanical, and chemical properties of the oiled areas of the supports that occur upon ageing due to oil-binder absorption in works of art on paper and printed material. In this framework, transmittance FTIR analysis has indicated that the presence of linseed oil induces the conditions to promote the deterioration of the oil-impregnated areas of the paper supports. However, the analysis of oil-impregnated mock-ups did not provide detailed information about the input of linseed oil formulations and the different types of paper support on the chemical changes that occur upon ageing. This work presents the results of ATR-FTIR and reflectance FTIR, which were used for compensating the previous results, proving indications on the effect of different materials (linseed oil formulations, and cellulosic and lignocellulosic papers) on the development of chemical changes, thus, on the condition of the oiled areas upon ageing. Although linseed oil formulations have a determining effect on the condition of the oiled areas of the support, the paper pulp content appears to have an input to the chemical changes that occur in the system of paper–linseed oil upon ageing. The results presented are more focused on the oil-impregnated mock-ups with cold-pressed linseed oil since results have indicated that this causes more extended changes upon ageing.