Bilayer Wood Membrane with Aligned Ion Nanochannels for Spontaneous Moist-Electric Generation.

Water-enabled electricity generation (WEG) technologies are considered to be an attractive and renewable approach to meet energy crisis and environmental pollution globally. However, the existing WEG technologies still face tremendous challenges including high material cost, harmful components, and specific environmental requirements. Herein, a high-performance wood-based moisture-enabled electric generator (WMEG) is fabricated. Natural wood is cut perpendicular to the tree growth direction and engineered by simple chemical modification. The obtained bilayer wood membrane has robust mechanical framework with aligned ion nanochannels, abundant dissociated functional groups, and spontaneous water adsorption in the air. At the relative humidity of 85%, one WMEG can generate a voltage of 0.57 V. The device can also effectively sense biological water information as a self-powered sensor. The biophile design contributes a practical moist-electric generation strategy that offers clean energy, especially for undeveloped and disaster-relief regions where electricity is limited by high cost or crippled power facilities.

Natural Compounds for Wood Protection against Fungi-A Review.

Wood is a renewable, versatile material with multiple applications and the largest terrestrial pool of sequestered carbon. However, it is susceptible to degradation, mainly caused by wood-decaying fungi. Since several traditional wood preservatives have been banned owing to their detrimental effects on humans and the environment, extending the lifespan of wood products using new generation natural preservatives is an imperative from the perspectives of human health and environmental protection. Several natural compounds of plant and animal origin have been tested for their fungicidal properties, including essential oils, tannins, wood extractives, alkaloids, propolis or chitosan; and their enormous potential in wood protection has been shown. Although they are not free of limitations, the potential methods to overcome their drawbacks and enhance their bioactivity already exist, such as co-impregnation with different polymers, cross-linkers, metal chelators or antioxidants. The presence of the discrepancies between laboratory tests and the field performance, as well as legislation-related problems resulting from the lack of standards defining the quality and performance of natural protective formulations, however, create an urgent need for further thorough research and arrangements. The collaboration with other industries interested in the utilisation of natural active compounds will reduce the associated costs, thus, will facilitate the successful implementation of alternative antifungal agents.

Mismatched Refractive Index Strategy for Fabricating Laser-Driven Wood Diffusers from Bulk Wood for Illumination Applications.

Laser-diode-based solid-state lighting is primarily used in state-of-the-art illumination systems. However, these systems rely on light-converting inorganic phosphors, which have low quantum efficiencies and complex manufacturing conditions. In this study, a mismatched refractive index strategy is proposed to directly convert natural bulk wood into a laser-driven wood diffuser using a simple delignification and polymer infiltration method. The resulting material has the potential to be used in laser-driven diffuse illumination applications. The optical performance of the laser-driven wood diffuser is optimized by changing the density of natural wood. The optimal coefficient of illuminance variation of the wood diffuser is as low as 17.7%, which is significantly lower than that of commercial diffusers. The illuminance uniformity is larger than 0.9, which is significantly higher than the ISO requirements for indoor workplace lighting. The laser damage threshold is 7.9 J cm-2, which is considerably higher than those of the substrates of commercially available phosphors. Furthermore, the optimized wood diffuser exhibits outstanding mechanical properties, excellent thermal stability, tolerance to harsh environmental conditions, and low speckle contrast. These results show that the laser-driven wood diffuser is a promising laser-color converter that is suitable for indoor, long-distance outdoor, undersea, and other high-luminance laser lighting applications.

Zirconium Component Modified Porous Nanowood for Efficient Removal of Phosphate from Aqueous Solutions.

Rapid urban industrialization and agricultural production have led to the discharge of excessive phosphate into aquatic systems, resulting in a rise in water pollution. Therefore, there is an urgent need to explore efficient phosphate removal technologies. Herein, a novel phosphate capture nanocomposite (PEI-PW@Zr) with mild preparation conditions, environmental friendliness, recyclability, and high efficiency has been developed by modifying aminated nanowood with a zirconium (Zr) component. The Zr component imparts the ability to capture phosphate to the PEI-PW@Zr, while the porous structure provides a mass transfer channel, resulting in excellent adsorption efficiency. Additionally, the nanocomposite maintains more than 80% phosphate adsorption efficiency even after ten adsorption-desorption cycles, indicating its recyclability and potential for repeated use. This compressible nanocomposite provides novel insights into the design of efficient phosphate removal cleaners and offers potential approaches for the functionalization of biomass-based composites.

Ni-doped MoS2 embedded in natural wood containing porous cellulose for piezo-catalytic degradation of tetracycline.

Wood is a natural material with low cost and easy recovery, which porous, layered, excellent structure and mechanical properties make it possible to apply in wastewater treatment. We have successfully grown MoS2 on natural wood containing porous cellulose and introduced the high conductivity circuit path provided by Ni nanoparticles to construct a new piezoelectric three-dimensional wood block for the efficient degradation of tetracycline. Ni/MoS2/Wood exhibited excellent piezo-catalytic degradation performance, and the degradation rate of tetracycline reached 95.96 % (k = 0.0411 min-1) under ultrasonic vibration. After 5 cycles, the degradation rate still reached 90.20 %. In addition, Ni/MoS2/Wood was used as the reactor filler to degrade tetracycline through piezoelectric response triggered by hydrodynamic force, and the degradation rate reached 90.27 % after 60 min. Further, the mechanism and the possible degradation pathways of tetracycline degradation were proposed. This low-cost, recyclable and stable three-dimensional wood block piezoelectric material provides a new idea for the practical application of wastewater treatment.

Natural Wood-Derived Macroporous Cellulose for Highly Efficient and Ultrafast Elimination of Double-Stranded RNA from In Vitro-Transcribed mRNA.

Double-stranded RNA (dsRNA) is a major impurity that can induce innate immune responses and cause adverse drug reactions. Removing dsRNA is an essential and non-trivial process in manufacturing mRNA. Current methods for dsRNA elimination use either high-performance liquid chromatography or microcrystalline cellulose, rendering the process complex, expensive, toxic, and/or time-consuming. This study introduces a highly efficient and ultrafast method for dsRNA elimination using natural wood-derived macroporous cellulose (WMC). With a naturally formed large total pore area and low tortuosity, WMC removes up to 98% dsRNA within 5 min. This significantly shortens the time for mRNA purification and improves purification efficiency. WMC can also be filled into chromatographic columns of different sizes and integrates with fast-protein liquid chromatography for large-scale mRNA purification to meet the requirements of mRNA manufacture. This study further shows that WMC purification improves the enhanced green fluorescent protein mRNA expression efficiency by over 28% and significantly reduces cytokine secretion and innate immune responses in the cells. Successfully applying WMC provides an ultrafast and efficient platform for mRNA purification, enabling large-scale production with significant cost reduction.

High-Performance Joule Heating and Electromagnetic Shielding Properties of Anisotropic Carbon Scaffolds.

Highly efficient electrical heaters along with excellent electromagnetic interference (EMI) shielding properties are urgently required for the progress of miniaturization electronics, artificial intelligence, and smart heating management setups. Herein, lignin removal, which comprises two efficient and versatile steps, followed by carbonization produces multifunctional carbon monoliths derived from natural wood. The obtained carbonized wood exhibits a high specific surface area (655.14 m2/g) and electrical (17.5 S/cm) and thermal conductivity (0.58 W/m·K), superhydrophilicity (contact angle of ∼0°), and excellent EMI shielding ability and Joule heating performance. The high electrical conductivity renders a low-voltage-actuated Joule heating performance and fascinating EMI shielding effectiveness of 55 dB, primarily resulting from the absorption mechanism. Moreover, regulation of the carbonized woods derived from the longitudinal to the radial direction enables transformation of hydrophilicity, strong thermal conductivity, and absorption-dominated EMI shielding to hydrophobicity, thermal insulation, and reflection-dominated EMI shielding. This is attributed to the unique anisotropic microstructure of carbon scaffolds. It is believed that these multifunctional carbon scaffolds can be used for intelligent electronics, EMI shielding, and thermal heating instruments.

Harvesting Electricity from Water Evaporation through Microchannels of Natural Wood.

When external pressure drives an electrolyte solution in a capillary tube with a charged inner surface, we obtain a streaming potential/current. This effect is also manifested when water flows through the microchannels of a tree, which is driven by capillary pressure and natural evaporation. Thus, by making use of natural evaporation, we took advantage of the anisotropic three-dimensional wood structures to fabricate nanogenerators drawing electricity from the streaming potential/current. As a result, direct current can be harvested continuously, simply through a piece of wood. A 300 mV open-circuit voltage and a 10 µA short-circuit current (ISC) were recorded from a single device, which surpassed the ISC values of most previous works by an order. By connecting five wood nanogenerators in series, a calculator can be completely functional, as a demonstration for practical application.

Bond Structures between Wood Components and Citric Acid in Wood-Based Molding.

Citric acid-based wood adhesive is considered a chemical-bonding wood adhesive. However, the detailed structures of the bonds between wood components and citric acid remain unknown. Here, we examine the chemical bonding structures between citric acid and wood by heteronuclear single quantum coherence-nuclear magnetic resonance (HSQC-NMR) analysis of wood-based molding using Japanese cedar (Cryptomeria japonica) and citric acid. In the HSQC-NMR spectrum of the wood molding, some esterified C/H correlation peaks appeared. The primary hydroxyl groups of polysaccharides, such as cellulose and galactoglucomannan, and the primary hydroxyl groups of the ß-O-4 and ß-5 substructures in lignin were found to be esterified with citric acid. In contrast, the secondary hydroxyl groups, except for xylan, barely reacted because of the steric hindrance. Additionally, the C/H correlation peak volumes of the reducing ends of mannan and xylan in the anomeric region increased after molding. It was clarified that the glycosidic bonds in the hemicelluloses were cleaved under the acidic molding condition with citric acid. The HSQC-NMR analysis revealed that the esterification of hemicellulose and lignin, and degradation of hemicellulose, proceeded under the molding condition. These results will promote understanding of the adhesive mechanism of citric acid-based wood adhesive and of the properties of the molding.

Bio-based Preservative using Methyl-ß-cyclodextrin-Essential Oil Complexes for Wood Protection.

Developing natural preservatives for wood protection is of great interest in sustainable construction and green building industries. This study was designed to determine the feasibility of using methyl-ß-cyclodextrin-essential oils (MßCD-EOs) complexes as potential bio-based preservatives for wood protection. Four essential oils (EOs) with proven antifungal properties, eugenol (EG), trans-cinnamaldehyde (CN), thymol (TM) and carvacrol (CV), were complexed with methyl-ß-cyclodextrin (MßCD) by a co-precipitation method. The inclusion of EOs in MßCD and the corresponding inclusion yield of the MßCD-EOs complexes were determined by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and ultraviolet-visible spectroscopy (UV/Vis), respectively. The maximum inclusion yields in MßCD-EG, MßCD-CN, MßCD-CV, and MßCD-TM were estimated to be almost 100%. MßCD-EOs complexes were impregnated into southern pine wood blocks and exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta, following procedures described in AWPA Standard E22 and E10. The penetration of MßCD-EOs complexes in wood was confirmed by fluorescence microscopic analysis after the selective dyeing of EOs encapsulated in MßCD. In comparison to the control wood samples, MßCD-EOs complexes treated wood exhibited a significant reduction in the mass loss from 16-36% to 2-18%, accompanied by improvement in radial compression strength loss from 81-92% to 29-67% after four-week fungi exposure.