Wood Science and Technology最新文献

Natural bamboo (NB) has inherent limitations, such as low thermal conductivity, tendency of hygroscopic expansion, and susceptibility to mold and mildew attack, which hampers its high value-added applications. This study developed high-performance bamboo-based polymer composites (BPC) by a delignification process combined with impregnation of AlN/BN-Epoxy resin. The thermal conductivity of BPC increased by 155.7% to 0.358 W/(m·K), as compared with NB, whereas hydrophobic modification of the surface reduced the hygroscopic volume expansion to below 3%. Application of pressure optimized the distribution of resin and interfacial bonding that could achieve a tensile strength of 115.61 MPa (10.2% increase compared to NB). Further, BPC showed improved thermal stability with peak pyrolysis temperature of 367.3 °C. Micromorphological analysis confirmed that continuous thermally conductive networks were formed by the alignment of AlN/BN filler in the epoxy matrix. Meanwhile, X-ray photoelectron spectroscopy (XPS) showed the presence of hydrophobic C-F bonds on the modified surfaces. This multi-scale approach could successfully overcome the limitations of bamboo’s performance, endowing BPC with combined thermal capabilities, mechanical strength, and environmental durability. These advancements make BPC a sustainable alternative to conventional underfloor heating substrates and heat dissipation components.

The increasing demand for sustainable high-performance materials has necessitated the development of alternatives to conventional glass- and petroleum-based plastics, particularly for transparent and mechanically robust applications. Transparent wood composites (TWCs) have gained attention as eco-friendly structural materials. However, existing studies have primarily focused on stem wood (SW) and epoxy-based polymers, which limit material flexibility, environmental sustainability, and diversified biomass utilization. To address this limitation, this study introduces a novel approach utilizing delignified biomass from branch (BH) and bark (BK) along with SW in combination with polyvinyl alcohol (PVA), a biodegradable and eco-friendly polymer matrix. The delignification process effectively removed the lignin, leading to enhanced cellulose crystallinity, increased optical transmittance, and improved polymer infiltration. Fourier-transform infrared spectroscopy (FTIR) confirmed substantial lignin removal, whereas X-ray diffraction (XRD) revealed differences in crystallinity across the biomass sources, with SW exhibiting the highest structural order. Optical analyses demonstrated that transparent composites made from branches with a smaller particle size (< 200 μm) and a wood powder ratio of 40% (TBH < 200 − 40) achieved the highest transmittance (85% at 600 nm) and superior light diffusion, making them suitable for optical and photonic applications. In contrast, transparent composites made from stem wood (TSWs) exhibited the highest mechanical strength, which was attributed to their densely packed fiber structure and high cellulose content, making them more suitable for load-bearing applications. BK-based composites demonstrated inferior mechanical and optical performance due to poor polymer adhesion and residual lignin content. These findings highlight the potential of alternative biomass sources for the development of high-performance TWCs, thereby enhancing their applicability in sustainable architecture, advanced optics, and flexible electronics.

In this study, the natural biomineralization process was simulated using NaClO₂ to remove lignin, thereby exposing the cellulose skeleton of poplar. The biocompatibility was enhanced through gelatin gel impregnation, which provided nucleation sites for subsequent SiO₂ mineralization. The in-situ mineralization of SiO₂ within the cell wall and cell cavity of poplar was achieved via the sol-gel method, utilizing tetraethyl orthosilicate as the silicon source, in conjunction with pH adjustment and a low-voltage electrostatic field. Consequently, SiO₂ mineralized delignification and hydrogel treated poplar wood composites (SDP) were prepared, featuring SiO₂ mineralized delignification and hydrogel treatment. The detection and analysis of the physical performance indicators of SDP revealed a weight% gain of 12.56%, an increase in absolute dry density, and significantly reduced radial and chordwise saturated water swelling rates and water absorption rates. Surface color and glossiness analyses indicated that the color of SDP darkened and its glossiness decreased. The water contact angle test demonstrated an enhancement in the hydrophilicity of the SDP surface. Fourier transform infrared spectroscopy analysis confirmed the formation of organic-inorganic hybrid structures between SiO₂ and poplar wood. Thermogravimetric analysis indicated that SDP exhibited improved thermal stability and increased activation energy, suggesting a more stable chemical structure and a more challenging pyrolysis reaction. Scanning electron microscopy and X-ray energy dispersive spectrometry revealed a uniform distribution of SiO₂ within SDP, resulting in a dense SiO₂ film layer and filler. This study presented a novel method for enhancing the performance and added value of fast-growing poplar wood, offering a new strategy for the development of high-performance biomass composite materials.

The use of light-harvesting substances to enhance natural photosynthesis has become a central theme in the field of materials and botanical studies. However, most light-harvesting substances are derived from sources that are not eco-friendly. Moreover, the limited range of light harvesting contributes to low efficiency. Herein, we report a novel large-size hydrophobic transparent wood decorated with near-infrared carbon dots (NIR-CDs) for harvesting sunlight. Residual oxidants were eliminated from dignified wood using ascorbic acid, and a hydrophobic coating Polydimethylsiloxane (PDMS) was applied to the surface of the transparent wood. Near-infrared carbon dots (NIR-CDs), derived from bamboo foliage within a schoolyard, were integrated into the transparent wood. The resultant LHW@NIR-CDs, with a recorded thickness of 1 mm and a light transmittance of approximately 90%, not only exhibit superior mechanical properties, but they also efficiently absorb and transform ultraviolet and near-infrared radiation into visible light, showcasing a prolonged excited state. The LHW@NIR-CDs enhance the natural photosynthesis of separated chloroplasts and live vegetation. Our engineered composite light-harvesting material, LHW@NIR-CDs, boosts the photosynthetic rate of isolated chloroplasts by 27.51%. When applied to practical agricultural cultivation, the use of LHW@NIR-CDs increased the dry weight and chlorophyll content of green pea shoots by 22.70% and 12.82%, respectively.

Natural woods are increasingly recognized as promising green candidates for high areal capacity wood-based hard carbon thick electrodes (WHCTEs). Their unique 3-D transport network features abundant straight, open channels aligned along the longitudinal direction, which has attracted significant attention in recent years. However, direct carbonization yields underdeveloped pore structures, restricting electrochemical active surfaces and lithium storage performance. To address this issue, calcium acetate (Ca(AC)₂) was employed as a templating agent to engineer hierarchical porous architectures. Systematic studies reveal adjustable Ca(AC)₂ dosage effectively modulates pore structures, with BET analysis confirming meso-/macropore distributions (2–130 nm) in all samples. This optimized porosity reduces electrode impedance and enhances lithium storage, delivering record areal capacities of 6.81/3.89 mAh cm^-2 at 0.1/1.0 mA cm^-2, which is 190%/110% higher than commercial graphite electrode (3.5–3.6 mAh cm^-2. Kinetic analysis further identifies an “adsorption-insertion” dual lithium storage mechanism. The widely distributed porosity significantly contributes to performance improvements, demonstrating a viable strategy for developing sustainable WHCTEs. These findings provide critical insights for designing thick carbon electrodes in alkali-metal-ion batteries.

This study investigates the radial densification of spruce wood using explicit finite element method simulations, focusing on the effects of various densification protocols. These protocols include quasi-static mechanical densification, transverse vibration-assisted mechanical densification, and self-densification through shrinking hydrogel fillings and their impact on the morphogenesis of folding patterns across different tissue types. The simulations incorporate the anisotropic mechanical behavior of wood tracheid walls and account for moisture and delignification effects using a hierarchical approach. Our results reveal the technological potential of targeted densification in creating tailored density profiles that enhance stiffness and strength. These insights offer valuable guidance for optimizing densification processes in practical applications.

Concerns about environmental deterioration, resource depletion and climate change have fueled a surge in worldwide interest in sustainable materials these recent years. This interest is especially strong in businesses that rely on non-renewable resources, such as building, transportation and packaging. In this paper, there has been a process toward investigating alternative materials, which have both environmental advantages and functional capabilities equivalent to, or even superior to, traditional counterparts. This review and meta-analysis aims to assess the present status of technical research on “transparent” wood manufacture, by utilizing even recyclable polymers. This study evaluates the methods used, the attributes gained, obstacles encountered and possible uses of such new materials. A technical literature search was undertaken utilizing several databases, such as PubMed and Web of Science and pertinent scholarly journals. The inclusion criteria included peer-reviewed studies on alternative wood production utilizing various polymers. The data extraction includes polymer types, production procedures, optical and mechanical properties and limitations described in the research. Several technologies, including impregnation and hot pressing, have been used to create novel composites. “Transparent” wood composites demonstrated promising optical transparency, mechanical strength and thermal stability when compared to standard approaches. Scalability, durability and cost-effectiveness have been referred as major problems in the manufacture of “transparent” wood composites, so to the moment their market impact is low. Despite limitations, the accurate research revealed potential uses in design, renewable energy and the sustainable packaging industries.

Gabon is a tropical country with vast forested areas, covering more than 80% of its territory. These forested areas contain a wide diversity of tree species that are still little studied, particularly in terms of the ecological profile of species in relation to their technological properties. This study aimed to highlight the differences among three ecological temperaments by analyzing fifteen properties from CIRAD physical-mechanical database. The species studied were forty-eight tropical hardwoods from Gabon. The results showed differences in ecological temperaments for two of the fifteen properties selected. Shade-tolerant species had better resistance to shear than hemi-heliophilous and light-demanding species. They were also relatively more resistant to fractionation than species in the other two groups. Statistically, there was no difference between the hemi-heliophilous and pioneer groups. Most of the properties studied were positively correlated with each other, particularly the mechanical properties with density. The linear relationships between wood density, on one hand, and shear, splitting, perpendicular tension and hardness, on the other hand, were found to be dependent on ecological temperament.

This study explores how flattening transforms transverse mechanical properties of bamboo through the redistribution of vascular bundles and residual stresses. Using dual-scale characterization and mechanical testing, we reveal that: (1) Flattening enhances transverse strength, with non-notched flattened bamboo achieving peak compression strength (23.3 MPa) and tension strength (9.4 MPa), while notched flattened bamboo excels in the small-size tension test (10.8 MPa); (2) Size effects arise from structural reorganization rather than stochastic defects; (3) Specific strength analysis demonstrates the lightweight advantage of notched flattened bamboo, confirming flattening improves the intrinsic mechanical efficiency beyond densification. These mechanistic insights address critical gaps in engineered bamboo design, enabling tailored applications.

The heartwood of Wenge (Millettia laurentii) has been used as decorative fine furniture owing to its luxurious color and regular fine grain. However, over time, heartwood turns from purple-brown to dark brown and eventually fades, reducing its wood value. The structures of the pigment compounds in wood and the mechanism underlying this discoloration are unclear. Using nuclear magnetic resonance (NMR) spectroscopy and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), fourteen compounds (1–14), including nine new dye compounds (2–5, 8, 11–14), were identified in the methanol extract of Wenge heartwood. Among them, 2, 4, and 5 are orange isoflavane quinones; 8 and 11 are yellow flavonols; 12 is a brown pterocarpan; and 14 is a purple benzofuran quinone, which are considered characteristic of Wenge. The absolute stereoconfigurations of 2, 3, 5, and 12 were identified by comparing the calculated electronic circular dichroism (ECD) spectra with the measured values. To investigate the color-change mechanism of Wenge, the structural changes under room fluorescent light of 2, the main dye compound, was determined using NMR and MALDI-TOF-MS analysis. These results indicate the formation of dark colored pterocarpane ortho-quinone, which causes the darkening of the wood surface.