Wood Cellulose Research Articles

Role of Lignin in Moisture Interactions of Cellulose Microfibril Structures in Wood

Wood is a complex, multi‐component material with a variety of applications. The properties of wood are especially sensitive to its moisture content and comprehending wood–water interactions is thus paramount. Understanding of the moisture interactions of the wood polysaccharide components, cellulose microfibrils and hemicelluloses, is improving. However, the role of lignin remains less clear. In this work, X‐ray scattering measurements were carried out on delignified spruce undergoing a desorption‐adsorption cycle, and the results were compared to previous data from untreated wood. In addition, a molecular model of the cell wall nanostructure, including the main chemical components, was used to support the experimental results. Based on the small‐angle scattering, delignification affects the arrangement of cellulose microfibrils in the cell wall by increasing their packing distance. Wide‐angle scattering shows that delignification has no substantial effect on the cellulose crystal structure and how it changes with moisture. Both the scattering results and simulations suggest that lignin is a passive, rather than an active participant in the moisture response of microfibril bundles in wood cell walls. Small‐angle scattering from fully wet delignified wood reveals a contribution that can be assigned to aligned nanometer scale pores which close during drying.

Bamboo powders effectively reinforcing the modulus of PBAT composites and creep resistance

AbstractBamboo has a short growth cycle and exists in large quantities in nature. This paper uses bamboo powders (BP) to reinforce polybutylene adipate/terephthalate (PBAT) modulus and creep resistance. The BP was surface modified by γ‐(2,3‐epoxypropoxy)propyltrimethoxysilane (KH560), and compounded with PBAT in a twin‐screw extruder. The results showed that the specific surface area and micropores of BP were considerably higher than that of common wood powders and cellulose and contributes significantly to the modulus and the creep resistance of composites. Compared with pristine PBAT, the tensile modulus, flexural modulus of K‐BP/PBAT composites increased by 225%, 608%, respectively, at a filler content of 25 wt%. In addition, the creep resistance of K‐BP25 was improved by a factor of 3.25 compared to PBAT. The enhancement mechanism of K‐BP was discussed, the large specific surface area and micropores of K‐BP provided more anchoring sites, which effectively increased the interfacial binding force between K‐BP and PBAT, and enhanced the nucleation ability of PBAT, thus improving the modulus and creep resistance of the composites. The results of this paper broadened the scope of application of PBAT.Highlights The bamboo powders effectively reinforcing the modulus of PBAT. The bamboo powders effectively reinforcing the creep resistance of PBAT. The special feature of K‐BP can provide more anchoring sites for PBAT. The K‐BP improves the nucleation ability of PBAT.

Identification of a Fomitopsis pinicola from Xiaoxing’an Mountains and Optimization of Cellulase Activity

Brown-rot fungi are large fungi that can decompose the cell walls of wood; they are notable for their secretion of diverse and complex enzymes that synergistically hydrolyze natural wood cellulose molecules. Fomitopsis pinicola (F. pinicola) is a brown-rot fungus of interest for its ability to break down the cellulose in wood efficiently. In this study, through a combination of rDNA-ITS analysis and morphological observation, the wood decay pathogen infecting Korean pine (Pinus koraiensis Siebold and Zucc.) was identified. Endoglucanase (CMCase) and β-glucosidase were quantified using the DNS (3,5-Dinitrosalicylic acid) method, and the cellulase activity was optimized using a single-factor method and orthogonal test. The results revealed that the wood-decaying fungus NE1 identified was Fomitopsis pinicola with the ITS accession number OQ880566.1. The highest cellulase activity of the strain reached 116.94 U/mL under the condition of an initial pH of 6.0, lactose 15 g·L−1, KH2PO4 0.5 g·L−1, NH4NO3 15 g·L−1, MgSO4 0.5 g·L−1, VB1 0.4 g·L−1, inoculated two 5 mm fungal cakes in 80 mL medium volume cultured 28 °C for 5 days. This laid a foundation for improving the degradation rate of cellulose and biotransformation research, as well as exploring the degradation of cellulose by brown rot fungi.

Assessment of Changes in Selected Features of Pine and Birch Wood after Impregnation with Graphene Oxide.

In this work, pine and birch wood were modified by graphene oxide using a single vacuum impregnation method. The research results indicate that the impregnation of wood with graphene oxide increases the crystallinity of cellulose in both pine and birch wood, and the increase in crystallinity observed in the case of birch was more significant than in the case of pine. FT-IR analyses of pine samples impregnated with graphene oxide showed changes in intensity in the absorption bands of 400-600, 700-1500 cm-1, and 3200-3500 cm-1 and a peak separation of 1102 cm-1, which may indicate new C-O-C connections. In the case of birch, only some differences were noticed related to the vibrations of the OH group. The proposed modification also affects changes in the color of the wood surface, with earlywood containing more graphene oxide than latewood. Analysis of scanning electron microscope images revealed that graphene oxide adheres flat to the cell wall. Considering the differences in the anatomical structure of both wood species, the research showed a statistically significant difference in water absorption and retention of graphene oxide in wood cells. Graphene oxide does not block the flow of water in the wood, as evidenced by the absorbability of the working liquid at the level of 580-602 kg/m3, which corresponds to the value of pure water absorption by wood in the impregnation method using a single negative pressure. In this case, higher graphene oxide retention values were obtained for pine wood.

Research on the preparation of cellulose nanocrystals from balsa wood using microwave-assisted synergistic deep eutectic solvent and H2O2 extraction

Utilizing natural balsa wood as the raw material, cellulose was prepared using microwave-assisted chlorocholine chloride/lactic acid deep eutectic solvents (DES) in synergy with H2O2, followed by further preparation of cellulose nanocrystals (CNCs) via ultrasound treatment. Initially, the optimal process for balsa wood cellulose preparation was explored through single-factor and response surface experiments involving microwave-assisted DES in synergy with H2O2 treatment. Subsequently, cellulose nanocrystals were prepared using ultrasound, and the resulting materials were characterized and analyzed for their chemical composition, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), nanoparticle size distribution, transmission electron microscopy (TEM) analysis, and thermogravimetric-differential scanning calorimetry (TG-DSC). The results indicate that the yield of cellulose after microwave-assisted DES in synergy with H2O2 treatment can reach 42.96%. Furthermore, the cellulose nanocrystals obtained after ultrasound treatment exhibit a particle size ranging from 10 to 20 nm, with an average length of 515.9 nm, a crystallinity of 86.72%, and demonstrate good dispersion and thermal stability.

Preparation and characterization of polymeric cellulose wood adhesive with excellent bonding properties and water resistance

Developing the most abundant cellulose resources in nature as wood adhesives is a challenging but significant work. In this study, an oxidized cellulose-hexamethylene diamine-urea (OCHU) resin adhesive, of high bonding performance, and excellent water resistance has been prepared. The cellulose was firstly enzymatically hydrolyzed to increase its solubility and expose more hydroxyl groups, then oxidized by sodium periodate (NaIO4) to generate a biological compound being rich of aldehyde groups. The OCHU adhesive was prepared by crosslinking oxidized cellulose (OC) with a synthetic reactive polyurea (HU) polymer, which was formed through the deamidation reaction between hexamethylenediamine (H) and urea (U). This adhesive exhibited a 24 h cold water soaking strength of 1.61 MPa, 3 h hot water (63 °C) strength of 1.05 MPa and a dry strength of 1.71 MPa. Compared to oxidized cellulose-hexamethylenediamine (OCH) adhesive, a significant increase of 60 % in this adhesive's wet strength. The Schiff base and addition reactions in the preparation were confirmed by XPS, solid-state NMR, and FTIR. This cellulose-based wood adhesive has great market competitiveness for mass production and application in the plywood industry, due to its excellent bonding properties.

Preparation and application of wood-supported piezocatalyst with high efficiency and stability via partial hydrolysis of wood cellulose and hemicellulose with Lewis acid

The conveniently recoverable piezocatalyst with self-floating and stable performance has drawn wide attention. Herein, MoS2 was anchored on 1-cm-square eucalyptus wood blocks via a facile hydrothermal/solvothermal process to fabricate two floating piezocatalysts, i.e., MoS2/unpretreated wood (MUW) and MoS2/pretreated wood (MPW). FeCl3 solution was used as a Lewis acid to pretreat the wood through partial hydrolyzing cellulose and hemicellulose for an purpose to creat rich micropores for MoS2 loading in the wood and to form MoFe heterojunction. The piezocatalytic properties and performance of the prepared wood were systematically studied. The scanning electron microscopy confirms MoS2 was anchored on wood surface. The macroscopic photos show that MoS2 penetrated through the MPW interior whereas it was only loaded on the wood surface layer. The X-ray photoelectron spectroscopy reveals the shift of Mo 3d and S 2p, verifying the heterojunction formation of MPW. The Fourier transform infrared spectra prove the partial hydrolysis of wood matrix. In comparison to MUW, MPW had excellent piezocatalytic property, wide pH adaptability, convenient recyclability and high stability. Sildenafil and Cr6+ ions could be completely removed in 20 and 15 min, respectively, by MPW. Contrastly, the removal efficiency of sildenafil and Cr6+ by MUW was 78.6 % and 68.3 % in 20 and 15 min, respectively. After five cycles of use, the removal ratio of sildenafil was 62.4 % by MUW and 90.5 % by MPW in 20 min. The mineralization efficiency of sildenafil reached 99.2 % in 30 min by MPW, and various types of N/S-containing intermediates were effectively degraded. The electron spin resonance characterization and active species scavenging experiments displayed that e− and •O2− were major active species responsible for Cr6+ piezoreduction by MUW and MPW, while •O2− and •OH were the dominant species accounting for sildenafil degradation by MUW and MPW, respectively. And •OH was not generated in the MUW piezocatalysis process. MPW had higher piezoelectric current and lower resistance at the electron transfer interface than MUW. Conclusively, this study paves a new pathway for preparing new floating piezocatalysts with easy recyclability and high stability from biomass for wastewater treatment.

A cellulose-binding domain specific for native crystalline cellulose in lytic polysaccharide monooxygenase from the brown-rot fungus Gloeophyllum trabeum

Cellulose-binding domains (CBDs) play a vital role in cellulose degradation by enzymes. Despite the strong ability of brown-rot fungi to degrade cellulose in wood, they have been considered to lack or have a low number of enzymes with CBD. Here, we report the C-terminal domain of a lytic polysaccharide monooxygenase from the brown-rot fungus Gloeophyllum trabeum (GtLPMO9A-2) functions as a CBD, classified as a new family of carbohydrate-binding module, CBM104. The amino acid sequence of GtCBM104 shows no similarity to any known CBDs. A BLAST search identified 84 homologous sequences at the C-terminus of some CAZymes, mainly LPMO9, in basidiomycetous genomes. Binding experiments revealed GtCBM104 binds selectively to native crystalline cellulose (cellulose I), but not to artificially modified crystalline or amorphous cellulose, while the typical fungal CBD (CBM1) bound to all cellulosic materials tested. The adsorption efficiency of GtCBM104 to cellulose I was >20-times higher than that of CBM1. Adsorption tests and microscopic observations strongly suggested that GtCBM104 binds to the hydrophilic regions of cellulose microfibrils, while CBM1 recognizes the hydrophobic surface. The discovery of GtCBM104 strongly suggests that the contribution of CBD to the cellulose enzymatic degradation mechanism of brown-rot fungi is much larger than previously thought.

Differential growth rate, water use efficiency and climate sensitivity between males and females of Ilex aquifolium in north-western Spain.

Dioecious plant species, i.e., those in which male and female functions are housed in different individuals, are particularly vulnerable to global environmental changes. For long-lived plant species, such as trees, long-term studies are imperative to understand how growth patterns and their sensitivity to climate variability differentially affect the sexes. Here, we explore long-term intersexual differences in wood traits, namely radial growth rates, water use efficiency quantified as stable carbon isotope abundance of wood cellulose, and their climate sensitivity in Ilex aquifolium trees growing in a natural population in NW Spain. We found that sex differences in secondary growth rates were variable over time, with males outperforming females in both radial growth rates and water use efficiency in recent decades. Summer water stress significantly reduced the growth of female trees in the following growing season, while the growth of male trees was primarily favoured by cloudy and rainy conditions the previous fall and winter combined with low cloud cover and warm conditions in summer. Sex-dependent lagged correlations between radial growth and water availability were found, with a strong association between tree growth and cumulative water availability in females at 30 months and in males at 10 months. Overall, our results point to greater vulnerability of female tress to increasing drought, which could lead to sex-ratio biases threatening population viability in the future.

Demystifying the tropics: FTIR characterization of pantropical woods and their α-cellulose extracts for past atmospheric 14C reconstructions

To ensure unbiased tree-ring radiocarbon (14C) results, traditional pretreatments carefully isolate wood cellulose from extractives using organic solvents, among other chemicals. The addition of solvents is laborious, time-consuming, and can increase the risk of carbon contamination. Tropical woods show a high diversity in wood-anatomical and extractive composition, but the necessity of organic-solvent extraction for the 14C dating of these diverse woods remains untested. We applied a chemical treatment that excludes the solvent step on the wood of 8 tropical tree species sampled in South-America and Africa, with different wood-anatomical and extractive properties. We analyzed the success of the extractive removal along with several steps of the α-cellulose extraction procedure using Fourier Transform Infrared (FTIR) spectroscopy and further confirmed the quality of 14C measurements after extraction. The α-cellulose extracts obtained here showed FTIR-spectra free of signals from various extractives and the 14C results on these samples showed reliable results. The chemical method evaluated reduces the technical complexity required to prepare α-cellulose samples for 14C dating, and therefore can bolster global atmospheric 14C applications, especially in the tropics.

Prediction of the dynamic pressure drop of filter media loaded with water mists based on the deposited droplet mass distributions and pore network model

Predicting the pressure drop of a filter is necessary, especially regarding the jump in the dynamic pressure drop of a filter without pre-filters when clogged by rain or fog droplets. However, the efficient prediction method for the pressure drop in cylinder filters loading with water mists in the pore network faces limitations due to the high requirements for microscopic images of materials and the need to consider for the increasing holding droplet capacity of filters. In this study, a systematic method that takes into account the distributions of the deposited droplet mass within the water-absorbed filter medium layers in the pore network model (PNM) was developed. The pore geometry and distributions were determined from 2D microstructure images, and the dynamic deposited droplet mass and water-absorbing capacity of fibers were combined with the changing saturation to optimize the PNM for calculating the dynamic pressure drop of the filter media. Specifically, the empirical equation of the self-defined equivalent single fiber filtration efficiency (ESFFE) describes the relationship between the changing single fiber filtration efficiency and the deposited droplet mass. The optimized PNM is suitable for predicting the behavior of bibulous wood cellulose fiber filter media. The dynamic pressure drop shows a slight increase before surging, following the typical “channel and jump” model. Although the calculations deviate slightly from the experimental results with 25 % deviations, this systematic method effectively predict the jump in pressure drop of the tested filter medium. Therefore, this systematic method for predicting pressure drop of filters holds promise in anticipating unsafe pressure drop jumps in filters installed in coastal areas.

Features of the formation of cohesive and adhesive strengths by non-structured and structured polyvinyl acetate films during wood gluing

The formation of a higher number of hydrogen bonds in the structured polyvinyl acetate film compared to the unstructured one was established by means of infrared spectroscopy method. It was concluded that the structured polyvinyl acetate film has a higher cohesive strength than unstructured. It was revealed that the films subjected to moisture loads (with the amount of sorbed moisture lower than the swelling limit of the adhesive film) would show greater cohesive strength compared to the films which were not subjected to moisture loads due to the formation of a higher number of hydrogen bonds. Based on the obtained results, it was predicted that the system "structured film after moisture loads/wood substrate" would exhibit the highest adhesive strength, explained by an increase in the number of hydrogen bonds between the film components and the wood cellulose. It was theoretically predicted that in order to provide high cohesive and adhesive strengths of polyvinyl acetate adhesive joints of wood ensuring, moisture saturation should be lower than the saturation limit of the wood fiber and the adhesive film simultaneously.

Wood Density and Carbon Concentration Jointly Drive Wood Carbon Density of Five Rosaceae Tree Species

Wood can store carbon and help mitigate global climate change. Carbon density (CD), the basis for measuring and analyzing C storage, is the product of wood density (WD) and C concentration, which are dependent on wood structure, cellulose concentration (CC), hemicellulose concentration (HC), and lignin concentration (LC). However, little attention has been paid to the C concentration of cellulose, hemicellulose, and lignin, which are fundamental factors in C storage and affect the credibility of accurate CD estimates. In order to disentangle the CD drives, WD, C concentration, CC, HC, and LC of the branch, stem, and root were quantified for five Rosaceae species from temperate forests in Northeastern China. The species were Sorbus alnifolia (Sieb.et Zucc.) K. Koch, Pyrus ussuriensis Maxim., Malus baccata (L.) Borkh., Crataegus pinnatifida var. major N. E. Brown, and Padus racemosa (Linn.) Gilib. The WD, CC, HC, and LC differed among species and tree organs, with the highest variability for the HC. The structural carbon concentration (SCC) was lower than the organic carbon concentration (OCC) and even the Intergovernmental Panel on Climate Change (IPCC) default value of 45%, with a maximum deviation of 2.6%. CD differed dramatically among species and tree organs. Based on SCC calculations, the highest CD was found in Sorbus alnifolia root (0.27 × 106 g/m3), while the lowest was found in Padus racemosa branch (0.22 × 106 g/m3). The results suggest that when estimating CD accurately at species level, it is important to consider not only WD but also structural carbohydrates and lignin concentration, providing important information on C fluxes and long-term C sequestration for forests. The study findings provide valuable insights into CD variations among tree species and organs and are valuable for forest management and policy development to improve carbon sequestration.

Wood cellulose films with different foldabilities triggered by dissolution and regeneration from concentrated H2SO4 and NaOH/urea aqueous solutions

Forests are a major source of wealth for Canadians, and cellulose makes up the “skeleton” of wood fibers. Concentrated H2SO4 and NaOH/urea aqueous solutions are two efficient solvents that can rapidly dissolve cellulose. Our preliminary experiment obtained regenerated wood cellulose films with different mechanical properties from these two solvents. Therefore, herein, we aim to investigate the effects of aqueous solvents on the structure and properties of wood cellulose films. Regenerated cellulose (RC) films were produced by dissolving wood cellulose in either 64 wt% H2SO4 solution (RC-H4) or NaOH/urea aqueous solution (RC-N4). RC-H4 showed the higher tensile strength (109.78 ± 2.14 MPa), better folding endurance (20–28 times), and higher torsion angle (42°) than RC-N4 (62.90 ± 2.27 MPa, un-foldable, and 12°). The increased cellulose contents in the H2SO4 solutions from 3 to 5 wt% resulted in an improved tensile strength from 102.61 ± 1.99 to 132.93 ± 5.64 MPa and did not affect the foldability. RC-H4 also exhibited better water vapor barrier property (1.52 ± 0.04 × 10−7 g m−1 h−1 Pa−1), superior transparency (~90 % transmittance at 800 nm), but lower thermal stability compared to RC-N4. This work provides special insights into the regenerated wood cellulose from two aqueous solvents and is expected to facilitate the development of high-performance RC films from abundant forestry resources.

Towards Sustainable Viscose-to-Viscose Production: Strategies for Recycling of Viscose Fibres

The potential for using discarded viscose textiles to produce high-quality viscose fibres is limited by the low molecular weight of the cellulose and its continued reduction in the recycling process. Herein, we present a straightforward approach of reprocessing discarded viscose textiles while achieving high-quality recycled viscose fibres. Discarded viscose textile was defibrated and centrifuged, and the resulting fibres were reprocessed under industrially relevant conditions. The produced viscose dope was fluid and resulted in viscose fibres with properties comparable to fibres made from commercial wood cellulose pulp (titer ~2 dtex; dry elongation ~16%, dry tenacity ~15 cN/tex). To explore the potential for a more environmentally friendly production process, the steeping step was performed twice (double-steeping), thereby producing a more homogeneous viscose dope. Through double-steeping, the consumption of carbon disulfide (CS2) could be reduced by 30.5%. The double-steeping method shows to be a suitable approach to reprocess discarded viscose textiles while reducing the environmental impact of the viscose process associated with the use of CS2. Our work demonstrates that discarded viscose textile has the potential to be part of a circular textile value chain.

Bonding Wood via Cellulose Aqueous Solution as Cell Wall Adhesive

The size of the wood plays a crucial role in determining its ultimate application. In order to break through the dimensions of natural wood, multiple pieces of wood are often bonded together with adhesives to form larger sizes. The physical and chemical properties of adhesives are different from those of natural wood, and this difference often leads to failure of the adhesive bonding interface. Herein, an aqueous solution of dissolved cellulose has been used as an adhesive to bond wood. The regenerated cellulose produced by recrystallization combines the wood fibers that originally existed on the wood surface cell wall. The resulting bonding wood interface consists of densely packed regenerated cellulose and wood cellulose fibers, which possess strong hydrogen bonds and physical entanglements. The shear strength has surpassed those of typical bio‐based adhesives and commercial adhesives. The same composition as natural wood endows this bonding interface with physical and chemical properties similar to natural wood such as weatherability. Bonding wood with this cellulose aqueous solution as an adhesive reduces the dependence on petrochemical‐based adhesives, and this facile and pressureless bonding strategy offers a promising route to manufacture sustainable wood composites with robust bonding interfaces.

Phloem Sap and Wood Carbon Isotope Abundance (δ13C) Varies with Growth and Wood Density of Eucalyptus globulus under Nutrient Deficit and Inform Supplemental Nutrient Application

Eucalyptus globulus, commonly known as blue gum or southern blue gum, is a tall, evergreen tree endemic to southeastern Australia. E. globulus is grown extensively in plantations to improve the sustainability of timber and fibre production across Australia. Sustainable forest management practices necessitate the consideration of ‘off-site’ carbon and ecological footprints. Pursuing optimal supplemental nutrient application and maximum growth rates is therefore critical to the establishment of a sustainable timber and fibre production industry. Biological indicators that can predict growth responses are therefore of extreme value. We investigated the carbon isotope abundance of wood cellulose (δ13Ccel) in E. globulus to determine potential relationships with the carbon isotope abundance of phloem sap (δ13Cphl) where the trees were subjected to different level of nutrient availability. This study also sought to determine the effect of nutrient additions on the growth of the E. globulus and to quantify the relationship between the volumetric growth of wood and δ13Ccel. Phloem sap and wood cores were collected from trees within study plots which were subjected to seven nutrient treatments over a two-year period in a monoculture E. globulus plantation in South Australia. Phloem sap was collected using the razor blade technique and wood cores were collected using a stem borer. The carbon isotope abundance (δ13C) of phloem sap and wood grown in the radial direction of the stem were determined. The basic and dry densities of wood were determined, and their relationships with phloem and wood δ13C were established. The δ13Cphl was significantly correlated with δ13Ccel. The relationship between δ13Ccel and the wood density of the respective wood sections was significant but did not consistently show the same pattern. There was no significant variation in basic density observed along the radial direction of the stem wood of the short-rotation E. globulus trees. A positive correlation was observed between δ13Ccel and the wood basic density, but the relationship was not consistent along the radial direction of the stem. However, positive correlations were observed between δ13Ccel and the air-dry density of respective wood sections. The relationship between phloem and wood δ13C and the relationship between δ13C and wood density along the radial direction of the stem needs to be considered while monitoring forest growth under nutrient- and water-limited conditions.

Wet torrefaction of biomass waste into high quality hydrochar and value-added liquid products using different zeolite catalysts

Wet torrefaction (WT) proves to be a highly efficient pretreatment method for biomass waste, resulting in the production of hydrochar and valuable liquid products. In this study, a groundbreaking chemocatalytic approach is introduced, employing various zeolite catalysts (H-ZSM-5, H-Beta, H–Y, H-USY, and H-Mordenite) in a batch reactor under a nitrogen atmosphere. This method enables the simultaneous one-pot production of levulinic acid (LA) and/or bio-ethanol during the WT process of wood cellulose pulp residue (WCPR), ultimately yielding high-quality solid fuel. The WT process involves at 220 and 260 °C, H2O/WCPR = 10, and torrefaction time at 15, 30 and 60 min. The study identifies that at 220 °C and 15 min, as the optimal temperature and time, for bio-ethanol production, achieving a selectivity of 59.0 % with the H–Y catalyst, while the highest amount of bio-ethanol (75.6 %) was detected in presence of H-USY zeolite at 260 °C after 60 min. In addition, it was found the formation of relatively high amount of LA (62.0 %) at 220 °C after 60 min but using the H-ZSM-5 catalyst. For the WT + Mordenite sample (220 °C, 60 min), the highest carbon content of 71.5 % is achieved, resulting in the higher heating value (HHV) of 27.3 MJ/kg, an enhancement factor of 1.36, and carbon enrichment of 1.48, with the sequence of element removal during WT prioritized as DO > DH > DC and the weight loss of 68 %. Finally, the reaction mechanism was proposed to elucidate the formation of liquid products after WT of WCPR with participation of zeolite catalysts. The main pathway involving the direct conversion of cellulose into hydroxyacetone, followed by the subsequent generation of ethanol through the C–C cleavage of hydroxyacetone while LA formed via well-known route which includes cellulose hydrolysis to form glucose, conversion to 5-HMF and the subsequent transformation of 5-HMF into LA.

Towards the Development of One-Step Scalable Self-Cleaning and Stain-Resistant Coating on Cellulosic Wood

Towards the Development of One-Step Scalable Self-Cleaning and Stain-Resistant Coating on Cellulosic Wood

Influence of reforestation tree species on decomposition of larch stumps and coarse roots: role of wood microbial communities and soil properties

Abstract Stumps and coarse roots are the most important coarse woody debris component in managed forests. However, their decomposition is still poorly understood, especially the influence of the characteristics of the microbial communities on wood decomposition. In this study, we investigated decaying larch (Larix olgensis Henry) stumps and coarse roots in reforestations of birch (Betula pendula Roth.), ash (Fraxinus mandshurica Rupr.), pine (Pinus sylvestris var. Mongolica), and larch in the northeast of China. We measured wood density loss, cellulose, and lignin concentrations, analyzed microbial community composition, and assessed the physical and chemical properties of woodland soils. Our findings reveal that larch stumps and coarse roots experienced the most rapid decomposition within birch reforestation areas, exhibiting significant density loss in stumps (33.84%) and coarse roots (43.68%). Bacterial diversity on larch stumps and coarse roots was highest in birch reforestation, with dominant phyla including Proteobacteria, Actinobacteriota, and Bacteroidota. Fungal diversity was also highest in birch reforestation, with Ascomycota as the dominant phylum in larch stumps and coarse roots. Furthermore, a mantel test analysis indicated that soil pH and temperature were significant factors in wood decomposition which affected microbial communities. This suggests that the choice of the reforestation tree species affects the decomposition of stumps and coarse roots by affecting soil properties and wood microbial communities. Understanding this process is vital for refining carbon balance evaluations, and enhancing ecosystem-level carbon modeling.