Wood Science and Technology最新文献

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.

The combined redox reaction of organic acids and hydrogen peroxide was utilized to promote the efficient pretreatment of biomass resources. In this study, a p-toluenesulfonic acid/hydrogen peroxide (TPHP) pretreatment strategy was designed for the effective deconstruction of bamboo and obtaining lignin nanoparticles (LNPs) directly. The results showed that the TPHP method had an excellent pretreatment performance at temperature 90 ℃, p-TsOH concentration 80%, time 30 min, and an H₂O₂ addition of 1.2 g/g_Bb. The cellulose recovery, hemicellulose removal rate, and delignification efficiency were 85.44%, 97.49%, and 95.98%, respectively. Meanwhile, the enzymatic hydrolysis efficiency of the optimal cellulose-rich residues increased from 33.43% to 85.06%. In addition, the recovered lignin had a high purity (> 98.40%), a lower molecular weight (M_w = 1479 g/mol), good homogeneity (PDI = 1.52), and uniform LNPs size (Mean diameter = 95.9 nm, PDI = 0.222). This study expanded the application of organic acid and hydrogen peroxide pretreatment and demonstrated that TPHP is a feasible and synergistic method in biorefining.

Salt crystallization at evaporation interfaces severely limits the efficiency and durability of solar-driven desalination systems, hindering their practical application. Here, we employed alkali-treated and dried rattan waste to construct a solar evaporator with a hierarchically porous substrate, and further incorporated poly-dopamine (PDA) to prepare the PDA-modified rattan evaporator (PDA-AR), achieving synergistically enhanced evaporation efficiency and long-term salt resistance. PDA-AR features contracted macroscopic pores (100–200 μm) and a dense framework, which increases the effective evaporation area. In a 20 wt% salt solution, PDA-AR exhibits a high evaporation rate (1.47 kg·m^− 2·h^− 1) and high photothermal efficiency (90.4%). And it maintains stable salt resistance for 30 consecutive cycles. Mechanistic studies reveal that PDA-AR enhances capillary forces and hydrogen bonding through pore contraction, thereby improving water transport capability and compressive strength via rapid salt dissolution. Furthermore, PDA-AR exhibits strong environmental adaptability, effectively purifying dye-contaminated water, as confirmed by UV–vis absorption spectra showing removal of methylene blue (~ 291 and ~ 664 nm) and methyl orange (~ 273 and ~ 465 nm). This work highlights microstructure regulation as a viable strategy to optimize solar evaporators, offering scalable solutions for sustainable desalination and water purification.

In the present study, a theoretical model was developed to elucidate the microscopic mechanism of hygrothermal recovery (HTR) in gelatinous fibers (G-fibers) of tension wood (TW) from the perspective of reaction kinetics. Yamamoto et al. (2022) proposed a hypothetical mechanism to explain the origin of HTR behavior in G-fibers, suggesting that two modes of denaturation of matrix components—namely, softening and degradation of non-crystalline polysaccharides in the G-layer—cause contractile recovery of the stretched cellulose microfibrils (CMFs). However, this mechanism remains qualitative and cannot quantitatively predict the complex HTR-strain behavior observed in G-fibers, such as the “initial recovery” and “continuous contraction” reported by Sujan et al. (2015). To address this limitation, the present study employed a numerical simulation approach based on a theoretical model. First, a mathematical rule was extracted from observed temperature- and time-dependent patterns of HTR-strain in the G-fibers. Second, the softening and degradation of non-crystalline polysaccharides in the G-layer matrix, as hypothesized by Yamamoto et al. (2022), were formulated within the framework of reaction kinetics. Third, by integrating this formulated mechanism with the extracted mathematical rule, a predictive model for HTR- behavior in G-fibers was developed. Finally, the newly developed model was used to quantitatively simulate experimental results. This model facilitates a rational elucidation of the microscopic mechanism of HTR in G-fibers by representing the dynamics of cell wall components and reproducing the macroscopic HTR-behavior observed in the G-fibers of TW.

With the growing utilization of fast-growing timber in the wood industry, issues such as poor dimensional stability and low durability have become increasingly prominent. Although heat treatment can improve those wood properties, the material remains susceptible to photodegradation under prolonged ultraviolet (UV) exposure, which limits its applicability in outdoor environments. In this study, ZnO was deposited onto the surface of heat-treated Taxodium hybrid ‘Zhongshanshan’ wood via magnetron sputtering to improve its resistance to light-aging. Results revealed that the ZnO coating was uniformly deposited with well-defined crystallinity and it did not compromise the visibility of the wood’s natural texture. After sputtering for 120 min, the light-aging resistance of heat-treated wood improved significantly. For example, the color difference (ΔE) decreased by about 50% as compared to the uncoated wood after light aging. By the way, the coating also can improve the waterproofing of wood surface, such as the initial water contact angle only decreased from 139.5° to 122.8° after light aging. Comprehensive characterization by SEM, XPS, EPR, and UV-Vis demonstrated that the ZnO coating inhibited the formation of free radicals and surface oxidation, thereby enhancing the wood’s resistance to UV-induced photodegradation. These findings highlight the effectiveness of magnetron sputtering as a physical modification approach for improving the long-term weathering performance of heat-treated fast-growing wood.

Lignin possesses the advantages of high carbon content and abundant functional groups, making it suitable as a supercapacitor electrode material. However, the microstructure of lignin-derived electrode materials obtained through traditional methods limits the effective utilization of energy storage capacity, resulting in a significant loss of electrochemical efficiency. Doping with heteroatoms in lignin-derived carbon can enhance its electrochemical performance and is a promising method for performance improvement. We employed a green and universal approach to design lignin-derived carbon materials by covalently grafting phosphorus source (DOPO) and nitrogen source (HDI) onto the lignin macromolecular framework through organic synthesis. Using modified lignin (NPAL) as a precursor, we achieved simultaneous carbonization and activation through a one-pot method. The nitrogen and phosphorus doping synergistically enhances pseudocapacitance activity (redox reactions), optimizes the hierarchical pore structure (increasing the specific surface area to 1756.79 m²/g), and improves charge transfer kinetics (reducing charge transfer resistance to 6.63 Ω). This results in a high specific capacitance (276.3 F/g @ 0.25 A/g, an increase of 275.56% compared to undoped materials), high energy density (12.5 Wh/kg), and cycling stability (capacity retention of 92.5% after 10,000 cycles), indicating a promising application prospect.

The content of wood chemical components (extractives, ash, Klason lignin, and polysaccharides) and Kraft-pulp properties (yield and kappa number) were directly determined for the inner and outer heartwood of 10-year-old 20 open-pollinated families in the third-generation Acacia mangium in Indonesia. The results show that the extractives, Klason lignin, and α-cellulose contents of outer heartwood were higher than those of inner heartwood. Relatively higher variance components of family were observed for polysaccharides and Kraft-pulp yield. Significant positive phenotypic correlations were found between stem diameter and either basic density or α-cellulose content, as well as between Kraft-pulp yield and α-cellulose content. Meanwhile, significant negative correlations were found between Kraft-pulp yield and organic solvent extracts or Klason lignin. Therefore, it is concluded that families with larger stem diameters and higher α-cellulose contents tend to produce higher pulp yield.

The outbreak of the hemiparasitic plant Loranthus europaeus poses a significant challenge to the protection and sustainable management of forest ecosystems, particularly oak forests in western Iran This study aimed to investigate the effects of L. europaeus on the morphological and chemical properties of Quercus infectoria wood in the northern Zagros region of Iran. In this research, 20 Q. infectoria trees (10 healthy and 10 infected) were selected. Trunk and branch samples from each tree were collected and analyzed in the laboratory. Fiber separation for morphological property assessments was conducted using Franklin’s method, and chemical composition analyses of the wood were carried out based on TAPPI standards. Data analysis involved checking normality using the Kolmogorov-Smirnov test, followed by one-way ANOVA and Tukey’s post-hoc test for comparisons. The results showed that the presence of L. europaeus significantly affected certain morphological properties, leading to reduced fiber diameter and cell wall thickness while increasing cell lumen diameter in both trunks and branches of the host. It had a significant impact on morphological coefficients, causing an increase in the flexibility ratio, and a decrease in the Runkle ratio. In terms of chemical properties, L. europaeus significantly decreased hemicellulose and increased lignin and extractives content, while its effect on other components was not statistically significant. These findings suggest that L. europaeus reduces fiber diameter, increases cell lumen diameter, and decreases cell wall thickness, resulting in diminished mechanical strength of the wood. Additionally, the reduction in hemicellulose and changes in extractive content significantly affect the industrial quality of Q. infectoria wood. This study demonstrates that L. europaeus infestation has profound impacts on both the structural integrity and industrial quality of Q. infectoria wood, providing key insights for sustainable forest management and utilization.

The structural complexity and inconsistent antioxidant performance of industrial lignin have long limited its high-value applications. In this study, we first clarified the central role of phenolic hydroxyl groups in antioxidant activity via targeted acetylation of tannin and lignin. Building on this insight, a green ethanol–water stepwise fractionation strategy (100%, 20%, 0%) was developed to deconstruct industrial lignin (KP) into three well-defined fractions (KE100, KE20, KE0) with tunable molecular properties. This solvent-gradient process enabled the orderly separation of high-molecular-weight hydrophobic components to low-molecular-weight hydrophilic ones. KE0, featuring the lowest molecular weight (M_w = 1000 g/mol) and highest phenolic hydroxyl content (4.23 mmol/g), exhibited markedly enhanced antioxidant performance (DPPH: 62%; FRAP: 2.97 µmol/mg). These findings establish a clear structure–activity relationship and demonstrate that ethanol-based fractionation not only improves lignin homogeneity but also unlocks its potential as a sustainable antioxidant platform. This work offers a scalable, eco-friendly pathway for advancing lignin valorization toward functional material applications.