Search Results (56)

Wood strength, renewability and appearance make it one of the most preferred and widely used natural materials in structural and cultural applications. The gradual degradation of wood from abiotic and biotic factors has an adverse impact on its structural durability and service life. This study investigates the effect of surface treatment of wood of the invasive tree species of tree-of-heaven, through short-term immersion in an acrylic polymer (Paraloid-B72) containing silica dioxide (SiO₂) nanoparticles at low concentrations (0–4% w/v) to impart hydrophobic behavior and weathering resistance. FTIR analysis confirmed the successful incorporation of the acrylic polymer and silica nanoparticles within the wood structure without altering the chemical integrity of the substrate. For both treated and untreated wood specimens, the physical properties (density, equilibrium moisture content, surface roughness, color-parameters), hygroscopic properties (swelling/absorption, contact angle) and weathering resistance tests were conducted using xenon-arc combined with wetting–drying cycles. The findings revealed that treated wood has significantly improved hydrophobic performance and dimensional stability, reducing moisture uptake. Treatment significantly increased the samples’ resistance to artificial weathering, with the effectiveness dependent on nanoparticle concentration. Although moderate surface color changes were observed in treated samples (compared to untreated ones), during their exposure to weathering, reduced lightness and slight increases in red and yellow chromatic coordinates were observed, with treated specimens exhibiting higher color stability during aging. Nevertheless, surface roughness increased significantly by the treatment, slightly restricting the method when a highly smooth surface touch is required. The proposed modification method appears promising to prolong the wooden structures’ service-life, meanwhile inspiring modern strategies for conserving historical timber structures that cannot be moved and should be protected by applying less invasive protective methods. Full article

Phi Man Long Long Rak Cave, located in Mae Hong Son Province, northern Thailand, is a prehistoric burial site containing ancient wooden coffins that have undergone biodeterioration, likely due to fungal activity. Both culture-dependent and culture-independent approaches were employed to characterize fungal communities and assess their roles in wood degradation. Culture-dependent analysis identified five Aspergillus isolates from the wooden coffins, most of which produced cellulolytic and hemicellulolytic enzymes; some isolates also produced organic acids, indicating significant degradative potential. Culture-independent analysis revealed a community dominated by Aspergillus, together with additional taxa such as Penicillium and Ceriporia that were not detected by cultivation, highlighting greater community diversity and demonstrating the complementarity of the two methods. Functional prediction indicated a predominance of saprotrophic fungi. The presence of shared dominant taxa between soil and coffin-associated substrates suggests ecological connectivity at the soil–coffin interface, although the direction of dispersal cannot be determined from the present data. All tested fungicides inhibited fungal growth, with the highest efficacy observed in the formulation containing the highest proportion of active components. Taken together, these findings provide insights into fungal biodeterioration processes and inform conservation strategies. Full article

In this paper, we utilized sodium titanate as a substrate to fabricate a supported antifungal repair agent capable of inhibiting fungi through the release of silver ions, and applied it to the preservation and restoration of wooden materials. The structural and material properties of sodium titanate were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and adsorption kinetic modeling. Furthermore, its effectiveness in wood restoration as well as its antifungal performance were evaluated. Results indicate that the synthesized sodium titanate exhibits a distinctive tubular structure, with a diameter of approximately 12 nm, a pore size of 7 nm, and a specific surface area as high as 310.91 m²/g. The abundant ion exchange active sites on the material surface provide conditions for the loading of silver ions. At 25 °C, the maximum adsorption capacity for silver ions reaches 515.5 mg/g, with an adsorption amount accounting for 34.0 wt.%. When combined with polyvinyl alcohol (PVA) for reinforcing wooden materials, it significantly increases the packing density of the reinforcing agent, ultimately enhancing the compressive strength of wood from 155.0 MPa to 412.2 MPa. Furthermore, owing to the antifungal effect of silver ions, the treated wood demonstrates effective resistance against the growth of Aspergillus niger. Full article

This research presents a comprehensive evaluation of semi-elastic polyurethane adhesives used for bonding wooden flooring, with a particular focus on both domestic (oak) and exotic hardwood species (teak, iroko, wenge, merbau). Given the increasing interest in sustainable construction practices and the growing use of diverse wood species in flooring systems, this study aimed to assess the mechanical, morphological, and surface properties of adhesive joints under both standard laboratory and thermally aged conditions. Mechanical testing was conducted according to PN-EN ISO 17178 standards and included shear and tensile strength measurements on wood–wood and wood–concrete assemblies. Specimens were evaluated in multiple aging conditions, simulating real-world application environments. Shear strength increased post-aging, with the most notable improvement observed in wenge (21.2%). Tensile strength between wooden lamellas and concrete substrates remained stable or slightly decreased (up to 18.8% in wenge), yet all values stayed above the 1 MPa minimum requirement, confirming structural reliability. Surface properties of the wood species were characterized through contact angle measurements and 3D optical roughness analysis. Teak exhibited the highest contact angle (74.9°) and the greatest surface roughness, contributing to mechanical interlocking despite its low surface energy. Oak and iroko showed high wettability and balanced roughness, supporting strong adhesion. Scanning electron microscopy (SEM) revealed stable adhesive penetration across all species and aging conditions, with no signs of delamination or interfacial failure. The study confirms the suitability of polyurethane adhesives for durable, long-lasting bonding in engineered and solid wood flooring systems, even when using extractive-rich or dimensionally sensitive tropical species. The results emphasize the critical role of surface morphology, wood anatomy, and adhesive compatibility in achieving optimal bond performance. These findings contribute to improved material selection and application strategies in flooring technology. Future research should focus on bio-based adhesive alternatives, chemical surface modification techniques, and in-service performance under cyclic loading and humidity variations to support the development of eco-efficient and resilient flooring systems. Full article

The carved lacquer horse-hoof-shaped box excavated from Yulin, Shaanxi Province, represents a typical example of lacquerware preservation in the arid environment of northern China, exhibiting multiple deterioration phenomena, including substrate deformation, lacquer film peeling, and pigment fading. To systematically analyze its structural composition and craftsmanship features, this study employed multiple analytical techniques, including ultra-depth microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), confocal laser micro-Raman spectroscopy (Raman), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Based on these analyses, a targeted conservation protocol was developed. Results revealed that the carved lacquer horse-hoof-shaped box has a wooden substrate structure, with the lacquer ash layer composed of mixed materials, including calcium carbonate (CaCO₃), quartz (SiO₂), and hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂). The lacquer film layer contains Chinese lacquer and plant oils, with cinnabar applied as surface decoration. Based on these findings, a stratified reinforcement conservation strategy was proposed: under dynamic monitoring with optical fiber sensors and three-dimensional scanning, the wooden substrate was reinforced with moisture-curable polyurethane (MCPU), the lacquer ash layer was strengthened with acrylic emulsion (Primal AC33), aged areas were restored with nano calcium hydroxide (Ca(OH)₂) aqueous dispersion, and polyethylene glycol (PEG 400) poultice application was implemented to restore the flexibility of the lacquer film. This research significantly enhanced the integrity and stability of the carved lacquer horse-hoof-shaped box, providing practical evidence and technical references for the scientific conservation of lacquerware excavated from arid regions of northern China. Full article

Carbon dioxide-derived oligocarbonate diols (OCDs) represent a promising class of sustainable raw materials that can enhance the environmental profile of polyurethane (PUR) coatings without compromising their performance. In this work, six oligocarbonate diols, differing in chemical structure (aromatic, aliphatic, and cycloaliphatic), were employed as modifiers in solvent-based PUR coatings designed for wood substrates. The study evaluates the influence of OCD’s chemical nature on the mechanical and optical properties of the resulting coatings. The results demonstrate that the structure of the oligocarbonate diol plays a decisive role in determining coating performance. PUR systems containing aliphatic soft segments exhibited the most favorable mechanical response, particularly in terms of wear resistance, outperforming coatings modified with cycloaliphatic and aromatic OCDs—wear reduction ranged between 43% and 71%. In contrast, the highest hardness values (0.46 and 0.41) were observed for the coatings incorporating aromatic moieties, indicating increased rigidity associated with aromatic structures. Importantly, adhesion at the wood–coating interface remained excellent and unaffected by the type of OCD used (cross-cut class I or II), confirming the compatibility of all investigated formulations with wooden substrates. Overall, the findings clearly show that newly developed CO₂-based oligocarbonate diols are effective and versatile modifiers for polyurethane wood coatings, enabling the tuning of functional properties while supporting more sustainable coating technologies. Full article

This study explores the enhancement of Beech wood (Fagus sylvatica L.) surfaces through the laser engraving of motifs inspired by Romanian textile heritage, combining cultural preservation with modern surface design techniques. A digitization and computer-aided design (CAD)-based workflow was employed to accurately transfer traditional motifs onto wood substrates. Engraving was performed using a nitrogen laser at ten different power settings ranging from 10 W to 150 W, followed by color analysis of the engraved areas. The resulting surfaces were evaluated using the International Commission on Illumination (CIELab) system to identify optimal engraving conditions. Based on colorimetric analysis, three laser power settings were selected for final motif reproduction: 30 W, 45 W, and 105 W. The process enabled the accurate rendering of a traditional three-color motif, achieving both visual fidelity and aesthetic appeal. Results demonstrate that color-based laser engraving allows precise, durable, and culturally significant ornamentation of wooden surfaces. The conclusions highlight the potential of this technique to add artistic and commercial value to wood products while preserving and promoting cultural identity. Full article

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. Full article

A novel self-healing brass powder/waterborne acrylic decorative coating for wooden substrates was developed, in which γ-methacryloxypropyltrimethoxysilane (KH570)-modified brass powder (with a coupling agent concentration of 6% and reaction solution pH of 5) was employed as the filler, and melamine-formaldehyde (MF) resin-encapsulated water-based paint microcapsules were utilized as the healing agent. The brass powder content and the core–wall ratio of the topcoat microcapsules were identified as the predominant factors affecting both the optical and mechanical properties of the self-healing brass powder/waterborne acrylic coating on Basswood surfaces. Therefore, the brass powder content was selected as the primary influencing factor. With concentration gradients of 0.5%, 1%, 3%, 5%, 7%, 9%, and 10%, and under constant conditions of 3% microcapsule content and room temperature curing, the effect of brass powder content on the properties of self-healing microcapsule coatings with different core–wall ratios was investigated. The waterborne acrylic wood coating containing 3% brass powder and 3% microcapsules with a core–wall ratio of 0.58:1 exhibited superior overall performance. This optimized formulation not only maintained excellent optical properties but also significantly enhanced mechanical performance, while preserving outstanding aging resistance, liquid resistance, and self-healing capability. The coating demonstrated the following comprehensive performance metrics: a glossiness of 24.0 GU, color difference (ΔE) of 2.13, chromatic aberration (ΔE*) of 13.68, visible light reflectance of 0.5879, dominant wavelength of 587.47 nm, visible light transmittance of 74.33%, pencil hardness of H grade, impact resistance of 2 kg·cm, adhesion rating of class 2, surface roughness of 2.600 μm, along with excellent aging resistance and liquid resistance properties, while achieving a self-healing efficiency of 19.62%. The coating also exhibited a smooth and uniform microscopic morphology, with the chemical bonds of both the modified brass powder and microcapsules remaining intact within the coating matrix. Full article

The conservation and restoration of water-gilded wooden cultural heritage, such as polychrome sculptures, frames, panels, altarpieces, etc., requires the use of fillers that guarantee structural stability, physicochemical and mechanical compatibility with the original support, and the ability to adapt to dimensional movements induced by thermo-hygrometric variations. This study, conducted as part of the DorART Project, analyzed the behavior of nine formulations, both commercial and non-commercial, selected through a review of the state-of-the-art specialized literature, along with the use of participatory science, which focused on the practices and materials most commonly used by professionals in the field. The experimental design was based on three types of specimens: two with wooden supports, selected for evaluating their interaction with the original material and with the traditional water gilding technique, and a third type for analyzing the individual behavior of the tested materials. Analyses of adhesion, tensile strength, Shore C hardness, gloss, abrasion test results, wettability, pH changes, and chemical composition were performed using ATR-FTIR spectroscopy. The results showed significant differences depending on the type of curing used and the composition and aging behavior of the specimen. Some of the fillers demonstrated improved compatibility with water-based gilding, facilitating workability and providing structural strength. M3 and M9 demonstrated an optimal balance of workability and aging stability. The results of this study can help restorers select materials based on their specific needs, considering the requirements of mechanical adaptation to the substrate, compatibility, and durability. Full article

Wildfires are increasing in extent and severity under anthropogenic climate change, with potential adverse impacts on native pollinators like wild bees. In 2019/2020, wildfires burned swathes of the Australian bushland. Whilst herbaceous angiosperms may flower in the post-fire environment, providing sustenance to native bees, pre-made holes created by wood-boring beetles that obligate cavity-nesting “renter” bees may take a longer time to recover. This may prevent native bees from colonising new areas or reduce the populations that have survived. To date, trap-nests, also known as bee hotels, have never been used as a tool to assist in providing nesting resources in post-fire environments. The project “Bee hotels to boost bees after bushfires” supported the recovery of native bee populations by installing artificial nesting substrates (bee hotels) in areas of high biodiversity value that were impacted by the 2019/2020 bushfires. This was achieved through monitoring of 1000 bee hotels (500 bamboo and 500 wooden) and visual surveys at five burnt sites and three control sites (nearby burnt sites without bee hotels) by a native bee ecologist from September–March 2021/2022. The bee hotel uptake was low initially, but by March, all hotels were occupied. Over 800 nests were created by bees in the bee hotels installed for this project and significantly more bees were observed in sites with bee hotels compared to control sites. Across sites, there was a significant negative association between honeybee density and nest occupancy, suggesting honeybees may be exerting competitive pressure on native bees in post-fire habitats. In conclusion, bee hotels, if designed correctly, can aid in boosting cavity-nesting bee populations following fires. Full article

Modern and contemporary artworks, due to technological developments in the synthesis of new pigments, are characterized by a pictorial palette composed of a wide variety of pigments. This diversity makes it increasingly important to carry out thorough characterization studies in order to gain a complete and comprehensive understanding of the properties of the numerous pigments in use today. In this work, 18 modern acrylic paints were characterized using micro-Raman spectroscopy with two laser excitation lines (532 nm and 633 nm). The analysed pigments can be classified as organic, inorganic, or mixtures, depending on their chemical composition. Specifically, the following pigments were investigated: Cobalt Blue, Permanent Blue Light, Ultramarine, Primary—Cyan Blue, Cerulean Blue, Cobalt Blue (Hue), Indanthrene Blue, Phthalo Blue, Van Dyke Brown, Permanent Green Light, Phthalo Green, Primary Red—Magenta, Cadmium Red Medium, Lemon Yellow, Cadmium Yellow Medium, Zinc White, Titanium White and Iridescent Silver. The pigments were applied to wooden and glass substrates to simulate the creative processes of actual modern and contemporary artworks. The aim was to define their composition, as this knowledge is essential for the protection, conservation and enhancement of cultural heritage. Full article

Due to compatibility issues between traditional reinforcing materials and the substrate of museum wooden artifacts, interface failure occurs after crack reinforcement, particularly under dry and wet cycling conditions. This significantly compromises the durability of reinforcement. To resolve this issue, dealkalized lignin was grafted onto epoxy acrylate (LEA) to synthesize a novel consolidant with both humidity responsiveness and mechanical compatibility. The resulting LEA exhibited excellent multilayer adsorption capability and demonstrated synchronous and uniform hygroscopic expansion behavior, closely matching that of archeological wood. DMA revealed that LEA2 has an elastic modulus of 261.58 MPa and a Poisson’s ratio of 0.35, comparable to artificially degraded wood, effectively mitigating interface stress caused by rigidity differences. Furthermore, LEA effictively reinforced micron-scale cracks while maintaining the original microstructure of the wooden artifact. This material provides a promising solution to the compatibility challenges of traditional consolidants under humidity fluctuations and offers a new approach for the stable preservation of museum wooden artifacts. Full article

Dou-Gong brackets, the distinctive structural element in ancient Chinese architecture, fulfill critical roles in load transfer, span reduction, and decoration, making its preservation vital for safeguarding wooden heritage buildings. This study investigates the combustion performance and residual load-bearing capacity of key Dou-Gong bracket components—Zuo-dou, Zheng-xin-gua-gong, and Qiao—exposed to varying fire conditions. The results reveal that an increasing fire load elevates heating rates and peak temperatures of wood substrates, resulting in a significant degradation of structural integrity. At a fire load of 55 kW, the peak temperatures at the bottom, joint edge, and top of the Dou-Gong brackets reach 755.3 °C, 489.9 °C, and 620.7 °C, respectively, representing increases of 2%, 65%, and 38%, respectively, compared to those observed at a fire load of 20 kW. Moreover, the charring rate of Dou-Gong bracket increases from 0.22–0.26 mm/min at a fire load of 20 kW to 0.50–0.56 mm/min at a fire load of 55 kW, accompanied by an increase in mass loss rate from 28.5% to 36.9%. These findings highlight the significant impact of fire conditions on the fire characteristic and structural integrity of Dou-Gong brackets, providing the first quantitative evidence of their degradation under fire exposure. By addressing this vulnerability, the study contributes to the scientific preservation of ancient wooden architecture under contemporary fire risk scenarios. Full article

Fire has been proven to threaten human lives and buildings significantly. Extensive research is being conducted globally to reduce fire risks, particularly in high-rise buildings that incorporate steel for structural support, timber for decorative elements, and cladding for insulation. Traditional passive fireproofing materials, such as concrete coverings, gypsum boards, and cementitious coatings, often lack aesthetic appeal. Intumescent coatings offer a promising solution to this issue. These coatings require a thin layer on the substrate to protect from fire, and the thin layer expands up to many times its original thickness when exposed to fire, forming an insulating char that acts as a barrier between fire and the substrate. This barrier prevents the steel from reaching critical temperature and helps maintain its integrity during a fire incident. Hence, intumescent coatings are a great choice for passive fire protection of load-bearing steel, wooden structures, timber, and cementitious buildings. Although some research articles discuss intumescent coating types, application methods, fabrication processes, cost-effectiveness, bonding performance, toxicity, and various uses, a comprehensive study encompassing all these topics still needs to be conducted. This review paper explores different types of intumescent coatings, their formulation and manufacturing methods, their application processes, and their use on various substrates. It also covers the key intumescent coating materials and their interactions during fire. Challenges and issues, such as fire protection time, char-forming temperature, and toxicity, are discussed. Full article