Wood Science and Technology最新文献

Rubberwood (Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg), a key economic species in tropical regions, presents significant processing challenges due to the wide variation in tension wood (TW) content. This study systematically compared the chemical composition and structural features of fibres from tension wood and opposite wood zones in rubberwood, aiming to elucidate the formation mechanisms of tension wood and provide theoretical support for its targeted modification and high-value utilization. Analyses included histochemical staining, chemical analysis, FTIR, thermogravimetric analysis (TGA), and thioacidolysis-GC-MS. The results showed that TW fibers featured a prominently thickened gelatinous layer (G-layer) composed of highly crystalline cellulose, with significantly reduced lignin content compared to NW. Thioacidolysis revealed that TW lignin not only exhibited a lower total content but also an increased proportion of syringyl (S) units, suggesting the adaptive regulation mechanisms within the lignin biosynthesis pathway. FTIR spectroscopy showed stronger O-H and aliphatic C-H stretching bands in TW, consistent with its higher cellulose content. The TGA results showed higher mass loss at 220–390 °C and lower char yield for TW, indicating cellulose-dominated decomposition behavior. This study elucidated the synergistic effect of S-unit enrichment and linkage rearrangement in TW lignin, underscoring that the G-layer’s high cellulose and low lignin architecture dictates thermal response. These findings improve the understanding of tension wood formation and provide practical strategies for enhancing the processing and utilization of plantation rubberwood.

Industrial beech timber steaming generates a process condensate that is typically treated as wastewater, despite its potential biological activity. This study explored the chemistry of beech steaming condensate (BSC) produced during an indirect industrial process and quantified its in-vitro effects on seed germination and early seedling growth in two model weeds, with maize as a crop reference. BSC was collected after two consecutive 12 h indirect-steaming cycles at 95 °C (25 mm beech timber). Chemical characterisation used UHPLC–QToF–MS (targeted identification/quantification of phenolics). Bioassays (0.25–4% v/v) measured germination, seedling length, root length and shoot length in tested plants, with four-parameter log–logistic models used to derive EC₅₀ and selectivity indices (EC₅₀,maize/EC₅₀,weed). It was found that BSC was dominated by phenolic acids (notably hydroxybenzoic and dihydroxybenzoic acids with syringic/vanillic hexosides), with modest flavonoids (chiefly (epi)catechin-3-O-hexoside and taxifolin glycosides) and trace lignans. Dose-dependent inhibition was observed across variables: EC₅₀ for germination ranged from 1.55% (A. retroflexus) to 3.44% (maize); for seedling length 0.45–0.95%; for roots 0.39–0.68%; and for shoots 0.46–1.58% (all % v/v). Selectivity index exceeded 1 for every variable (1.45–3.43), indicating weed-over-crop sensitivity. Effective inhibition occurred at ~ 1–2% (v/v), close to the as-produced condensate concentration (dry matter 2.2% w/v). Under process-realistic conditions, BSC exhibits a benzoic-acid–dominated fingerprint and selective inhibition of early weed development relative to maize. This establishes a laboratory proof-of-concept for valorising an existing wood-industry stream and motivates greenhouse verification, storage-stability checks and small-plot tests.

Despite its importance in forestry and wood science, the conventional classification of juvenile and mature wood remains ambiguous. Juvenile wood is typically defined as the inner region of the trunk where wood properties change rapidly with cambial age, i.e., the number of growth rings from the pith. The surrounding mature wood is characterized by smaller variations in these properties. A major limitation of this traditional framework is that the distinction between juvenile and mature wood depends strongly on which specific properties are considered. Moreover, the relationship between the degree of property variability and tree maturation has not been clearly established. This study demonstrates that the age-dependent evolution of a density operator, computed from the near-infrared (NIR) spectral matrix at each cambial age, effectively represents the tree maturation process. The density operator encapsulates comprehensive information on both individual variability and the interrelationships among multiple wood properties. Four representative tree species with distinct anatomical features were investigated. Changes in the density operator indicate that the transition from juvenile to mature wood corresponds to a phase transition in the variability of wood properties. Tree maturation is thus interpreted as a shift in the xylem tissue state from disorder to order. The proposed approach is canonical—it is independent of the specific wood properties considered, incorporates information on individual variation, and can therefore be applied to a wide range of data sources beyond NIR spectral measurements.

Amid worsening energy shortages, the demand for clean energy and high-performance energy storage devices has surged, driving significant research interest in supercapacitor electrode materials. This study pioneered a novel hierarchical composite architecture integrating ball-milled Melaleuca bark-derived activated carbon (BAC) with nickel-cobalt layered double hydroxide (Ni-Co LDH) via a facile solvothermal method. Systematic optimization of synthesis parameters including the Ni: Co molar ratio, solvothermal reaction temperature/duration, and the BAC to NiCo-LDH mass ratio unveiled that controlled conditions induced a distinctive urchin-like spherical morphology, where vertically-aligned LDH microspheres uniformly anchor onto the porous BAC scaffold. This unique structure fosters a synergistic dual-function: BAC serves as a conductive backbone that mitigates LDH aggregation and enhances ion transport kinetics, while Ni₃Co₆-LDH delivers robust pseudocapacitance. Crucially, the optimal BAC/Ni₃Co₆ composite achieved a remarkable specific capacitance of 587.5 F g^− 1, surpassing pristine BAC and Ni₃Co₆-LDH by 101.2% and 79.0%, respectively. Furthermore, the assembled asymmetric supercapacitor device demonstrated exceptional cycling stability, maintaining 99.7% coulombic efficiency after 6000 charge-discharge cycles. This work not only valorizes Melaleuca bark as a sustainable precursor for high-performance carbon materials but also establishes a rational design paradigm for engineering advanced biomass-derived composite electrodes.

Oak barrels are worldwide used wood for alcoholic beverages ageing; in Brazil, tropical woods have been studied for cachaça ageing, highlighting Amburana cearensis due to its richness in aromatic extractives and phenolic compounds. This study investigates the chemical and aromatic profiles of cachaça aged in Amburana cearensis barrels, aiming to support quality enhancement and market expansion strategies. Twenty-one samples aged from 4 months to 4 years were collected and submitted to analysis such as physical–chemical (including colour, ABV, acidity, Total phenolic content, Antioxidant analyses), volatile compounds (GC-FID and GC–MS) and copper content (FAAS). Forty-five volatile compounds were identified, contributing to fruity, floral, woody, and sweet aromas. Samples exhibited variation in phenolic content, antioxidant activity, and colour. While alcohol and acidity levels mostly complied with legal standards, excessive ethyl carbamate and copper levels in some samples raised safety concerns. High ethyl acetate and acetaldehyde levels were linked to aroma and oxidation, respectively. This work highlights the sensory potential of Amburana-aged cachaça and underscores the need for controlled processing to ensure safety, enhance quality, and valorise native wood use in artisanal distillate production.

When trees of the genera Aquilaria and Gyrinops (from the Thymelaeaceae family) are injured, they produce a black resinous deposit called agarwood, which is sought after because of its fragrance and medicinal properties. As natural agarwood sources are depleted and collection from the wild is restricted, artificial agarwood has been developed. Furthermore, the quality of commercial agarwood is determined through subjective evaluation by human experts, and standard quality controls are lacking. In this study, we evaluated the effects of chemical injury treatments using plant hormones (salicylic acid, methyl jasmonate, and ethylene), which have attracted attention in the production of artificial agarwood. Resin-deposited areas on the treated branches were quantified using image analysis as an objective quality indicator. In addition, the yield of 2-(2-phenylethyl)chromones (2PECs), which are essential fragrance compounds in high-quality agarwood, was quantified. Treatment with salicylic acid or methyl jasmonate resulted in resin-deposited areas more than double those of the control, with enhanced 2PEC content, such as oxidoagarochromone A, B, and C, and agarotetrol. Additionally, treatment of wood with over-the-counter medicines containing salicylic acid resulted in a dramatic increase in the resin-deposited area and 2PEC content. Furthermore, the total oxidoagarochromone A, B, and C content was positively correlated with the resin-deposited area in the six months treatment samples. This is the first study to quantitatively demonstrate the effect of plant hormones on the agarwood resin-deposited area and 2PEC content, especially oxidoagarochromone A, B, and C, and agarotetrol, simultaneously, and is expected to contribute to further development of artificial agarwood production, quality evaluation methods, and elucidation of the resin deposition process.

A composite adsorbent material for CO₂ capture was prepared using low-density, high-porosity balsa wood (BW) as the matrix, with the introduction of CuBTC and graphene oxide (GO). Characterization via scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Raman spectroscopy, and X-ray diffraction (XRD) confirmed the uniform synthesis of the octahedral CuBTC within the wood pores. The introduction of GO increased the loading of CuBTC by 28.3%, with the final loading reaching 46.7%. FTIR analysis revealed interfacial interactions—hydrogen bonding and Cu²⁺ coordination. Compared to pure CuBTC, the composite exhibited higher thermal stability (up to 500 K) and excellent water resistance, with minimal structural changes after 6 h of immersion. Its microporous surface area, pore volume, and average pore diameter reached 229 m²·g^-1, 0.12 cm³·g^-1 and 2.01 nm, respectively. Under conditions of 298 K and 1 bar, the CO₂ adsorption capacity reached 1.93 mmol·g^-1, and it exhibited excellent cycling stability. The average CO₂ adsorption heat was 32 kJ·mol^-1, indicating that the adsorption mechanism was primarily physical adsorption, i.e., wood acted as a high-speed channel for CO₂ transport, while the unsaturated copper sites exposed on CuBTC in the wood pores interacted electrostatically with the quadrupole moment of CO₂. Additionally, this composite material exhibited high CO₂/N₂ selectivity (up to 71), outperforming pure CuBTC, highlighting its potential for application in CO₂ capture. This study is valuable for the functionalization of wood.

Increasing pressure on high-quality timber resources like Norway spruce necessitates enhanced material efficiency, driving interest in hybrid wood products. This study evaluated flax natural fiber-reinforced polymer reinforcement for spruce laminated veneer lumber. Reinforcement composites using conventional epoxy and bio-based polyfurfuryl alcohol matrices were bonded to the lumber with structural wood adhesives (melamine-urea-formaldehyde and polyurethane); direct reinforcement using these adhesives was also tested. Mechanical properties (tensile, shear, 4-point bending, impact) were assessed, including moisture-dependent behavior at 35–85% relative humidity. Results demonstrated effective bonding of prefabricated fiber composites using both wood adhesives, yielding significant increases in the lumber’s bending stiffness and strength. Notably, the polyfurfuryl-alcohol-based composites provided the highest stiffness gains, validating its bio-based potential, while epoxy-based composites exhibited superior toughness and impact resistance. Both systems maintained significant reinforcement despite expected moisture sensitivity. Direct reinforcement attempts using the wood adhesives revealed processing limitations. Findings confirm natural fiber reinforcements as a viable strategy for enhancing wood performance, enabling advanced hybrid wood products, contributing to more efficient use of wood resources.

Heat treatment is a widely used method to enhance the dimensional stability of wood, yet the relative contributions of hygroscopicity and deformation sensitivity to this improvement unclear. This study systematically investigates how these factors influence the dimensional stability of latewood (LW) and earlywood (EW) in Chinese fir subject to heat treatment at 180, 200, and 220 °C. Full-field in-plane strain responses were quantified using digital image correlation, and transverse hygro-deformation was visualized based on Greenhill’s theory. The dimensional changes of EW and LW per unit change in moisture content—i.e., the shrinking and swelling coefficients—were also quantified. Chemical and structural changes, including hemicelluloses degradation, lignin enrichment, and hydroxyl groups reduction, led to increased crystallinity and decreased hygroscopicity. Heat-treated wood showed reduced dimensional changes in both radial and tangential directions, particularly in LW. The shrinking coefficient significantly decreased after heat treatment, while the swelling coefficient remained relatively stable. Desorption and absorption isotherms revealed reduced sorption hysteresis as well as swelling hysteresis, particularly above 10% moisture content. Two-dimensional visualizations demonstrated an overall reduction in in-plane deformation although anatomical anisotropy remained. These findings provide insight into the mechanisms underlying dimensional stabilization in heat-treated wood and offer guidance for optimizing the heat treatment process.

To minimize greenhouse gas emissions, the development of biobased building materials is gaining increasing priority. Wood’s insulation performance can be enhanced by creating additional porosity through the removal of non-cellulosic substances. Although delignification techniques have been used in the pulping industry to produce cellulose pulp, they have evolved to produce cellulose nanofibers or cellulose scaffolds for functional materials. Various top-down delignification techniques have been suggested for solid wood, but most studies have focused on a single technique applied to a specific wood species, making it difficult to compare the effectiveness of different methods. This paper addresses this gap by presenting a comparative analysis of literature-established delignification techniques applied to solid wood pieces: soda pulping, alkaline sulfite pulping followed by hydrogen peroxide bleaching, and organosolv pulping followed by sodium chlorite bleaching. This study evaluated the impact of these techniques by examining the changes in mass loss, chemical constituents and FTIR spectra of French poplar wood planks of 100 cm³ after treatment. The combination of organosolv pulping by alcoholysis and sodium chlorite bleaching was found to be the most effective method for complete lignin removal. Our findings reveal the strengths and limitations of these methods, providing insights into the selection of wood modification techniques for upscaling purposes. Further research on drying delignified wood is required to complete a preliminary study of the industrialization of insulating wood. These advancements promoted the sustainable use of wood as a mechanically strong thermal insulator to reduce building energy consumption and mitigate climate change.