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The deposition of lignin and carbohydrates in different cells and morphologically distinct cell wall layers during the development of Calamus simplicifolius was investigated by combined microscopic techniques. Lignin autofluorescence images showed that protoxylem vessels were the first to differentiate among vascular elements. At the subcellular level, high spatial resolution Raman images revealed that the deposition of carbohydrates in fibers preceded that of lignin. Additionally, the lignin and carbohydrates concentration in the secondary wall (SW) varied among different cell types. The carbohydrates concentration in SW of fibers presented the highest level, which was much higher than that in vessels and parenchyma. High concentrations of lignin were most visible in the SW of vessels, followed by fibers, with the lowest amount visible in parenchyma. Within the morphologically distinct cell wall layers, the carbohydrates and lignin in fibers SW and cell corners deposited rapidly at the early stage from the 7th to the 10th internode, while the deposition rate decreased from the 10th to the 50th internode. The findings have substantial theoretical significance to understand the biosynthesis of rattan cell walls.

The sol–gel method was used to prepare rattan-based silicon carbide (R–SiC) composite ceramics under different pyrolysis parameters through adjustment of the temperature and retention time of the one-step pyrolysis process. The crystalline phases, microscopic morphology, element distribution and specific surface area of the silicon carbide (SiC) were characterized by X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), X-ray fluorescence spectrometer (XRF), field-emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), and N2 physisorption. The results showed that the R–SiC prepared at different pyrolysis parameters was able to retain the porous structure of pristine rattan stem. The R–SiC prepared at 1500 ℃ for 120 min possessed the lowest density (0.25 g/cm3), the largest specific surface area (43.38 m2/g) and the highest SiC yield (44.24%). The SiC whisker was the major SiC morphology on the cross section of the R–SiC. Furthermore, the pyrolysis parameters were optimized with the SiC preparation process reaction mechanism, and material transformation methods were also discussed. This one-step pyrolysis process simplified the preparation of biogenic SiC ceramics and thus provided a potential route for the value-added utilization of rattan.

Moso bamboo (Phyllostachys edulis), an apt example of an anisotropic, functionally graded composite material, is the most important commercial bamboo species of China. This species has excellent mechanical properties due to its unique vascular bundle structure. This article examines the variation in mechanical properties of single vascular bundles with respect to their location within a bamboo culm. The mechanical exfoliation method was used to prepare the single vascular bundle. This study found that moso bamboo has superior stiffness and strength. Additionally, the variation in properties was large in the radial direction but minimal in longitudinal direction. The large variation in mechanical properties of vascular bundles can be ascribed to the synergistic effect of the fibrous sheath and parenchyma rather than to changes in fibrous sheath properties. This study provides a basis for the structure application for moso bamboo.

The application of cellulose fibers with varieties of allomorphs is of much interest. However, the crystal structural changes of certain allomorphs during the wet chemistry process are often ignored. In this work, the recrystallization behavior of softwood pulp cellulose IIII back to cellulose Iβ with tg conformation by hydrothermal treatment at different temperatures is carefully evaluated and calculated. The treatment contributed to the distortion of crystallites and lower crystallinity including the formation of intermediate amorphous phase at 60 °C. Higher hydrothermal temperature (100 °C) resulted in the reversion to cellulose I (59.7%) as well as retention of 12.5% of cellulose III, suggesting the uncompleted recrystallization during the process. With the loosened fibril structure and more amorphous regions, the thermal stability of recrystallized cellulose I is significantly dropped, far below that of original cellulose I/III materials. This study may provide new thoughts on the industrial processing and application of the polymorphic cellulose materials.

The cell wall mechanical properties are an important indicator for evaluating the overall mechanical properties of natural bamboo fibers. Using the nanoindentation technique, the variation of the mechanical properties of the fiber cell wall of Bambusa pervariabilis culms with different ages and different positions (both radial and longitudinal) was studied. Moreover, x-ray diffraction (XRD) was employed to measure the microfibril angle (MFA), and the correlation between the MFA and the mechanical properties of the fiber cell wall. The results showed that there was a remarkable difference in the fiber cell wall mechanical properties at different ages and at different radial and longitudinal positions. However, at different ages and at different positions, the absolute value of variation of MFA was less than 1° and was very minor. Furthermore, there was no significant correlation between the fiber cell wall mechanics and MFA, indicating that the mechanical property of the fiber cell walls might be synergistically affected by many factors.

Water exists in lignocellulosic materials throughout the whole process from the plant growth to raw materials processing and utilization. The fiber saturation point (FSP) is the inflection point of the physical and mechanical properties of lignocellulosic materials and has an important influence on their physical and mechanical properties. This paper investigates the FSP of Calamus simplicifolius by the low-field nuclear magnetic resonance (LF-NMR) method and two conventional methods including the saturated salt solution method and dynamic vapor sorption (DVS) method. The average FSP values determined by the LF-NMR method, the saturated salt solution method and the DVS method are 38.15%, 32.54% and 28.96%, respectively. The study showed that the FSP values determined by the LF-NMR method were higher than those determined by the two conventional methods. The two conventional methods are simple and cost-effective and are able to directly measure whether the rattan properties are changing with moisture content. From the thermodynamics standpoint, even within the ideal solution limit, free water is present at relative humidity (RH) of less than 100%. Therefore, extrapolation to 100% RH was not strictly correct. The amount of water in rattan in different states could be quantified by the LF-NMR method, and the FSP value was determined by the ratio of the measurements above and below the water melting point. Furthermore, the LF-NMR method is faster and non-destructive compared to the two conventional methods.

Density (D) and moisture content (MC) are two important physical properties of wood and bamboo, which are highly correlated with many other physical and mechanical properties. In this study, the X-ray computed tomography (CT) technique was used to determine the D and MC of poplar (Populus xiangchengensis) and bamboo (Phyllostachys edulis). There was a statistically significant difference in the CT-measured numbers for D and MC between these species. The D-CT and MC-CT linear models for both species were independently established: Dpoplar = 0.00098 × H + 1.02603, Dbamboo = 0.00118 × H + 0.98684, MCpoplar = 0.00309 × H + 1.89982, and MCbamboo = 0.00131 × H + 0.31488, where H is the CT number. The determination coefficients, R2, of the models were all higher than 0.97. Additionally, the R2 values obtained for model validation were also all higher than 0.97. These results indicated that it is feasible to reliably determine D and MC of wood and bamboo using the X-ray CT technique. This study aims to provide reference data for CT detection of the D and MC of wood and bamboo.

This research aimed to investigate the compressive fracture behavior and the compressive strength parallel to the grain in relation to moisture contents (MC) below and above the fiber saturation point (FSP) in Calamus simplicifolius cane. FSP of the rattan was investigated using a dynamic vapor sorption (DVS) apparatus, and the fracture behaviors of compression parallel to grain were analyzed by three-dimensional X-ray microcomputed tomography. The study indicated that the value of FSP derived from the DVS method was 25 percent. The average compressive strength parallel to the grain was found to be 39 MPa at 3 percent MC, 30 MPa at 10 percent MC, 17 MPa at 12 percent MC, 12 MPa at 27 percent MC, and 10 MPa at 45 percent MC. The strains of the yield and densification stage were prolonged with increasing MC, whereas the stress in the linear elastic stage decreased with increasing MC. The cracks of the rattan core and the deflection angle at higher MC were larger than that of low MC. Below the FSP, the compressive failure of the rattan showed a shear band oriented around 45° to the loading axis, and the surface was rough. Above the FSP, the rattan samples showed brooming failure. The interface among fiber bundles was delaminated and the fiber surface in the failure area was smooth. The fracture toughness of the rattan was higher than that of wood, which suggests that the rattan might be more suitable for modeling and curved materials.

The anatomical characteristics of culms in Bambusa pervariabilis bamboo at different ages and heights were investigated by microscopy and image analysis. Among the two vascular bundle types found in culms, the broken-waist type was considered typical, with the following measurements: average proportion of fibrous tissue, 41.53 percent; length, 1.75 mm; slenderness ratio, 117; and Runkel ratio, 4.00. These values were close to those of the moso bamboo (Phyllostachys edulis), which is commercially relevant in China. Age and height significantly influenced the anatomical characteristics of B. pervariabilis: with an increase in age, both the length and double-wall thickness of the fiber gradually increased, whereas its lumen diameter decreased. The width of vascular bundles and the length, width, double-wall thickness, and lumen diameter of fiber markedly decreased from the bottom to the top. Therefore, B. pervariabilis is an ideal raw material for pulping and papermaking, and its performance is close to that of moso bamboo.

Density and moisture content (MC) are two of the most important wood performance indexes, which are highly correlated with many other physical and mechanical properties of wood. X-ray computed tomography (X-CT) technology was used to analyze the difference in the CT number of the heartwood and sapwood of Chinese white poplar (Populus tomentosa) and Masson pine (Pinus massoniana) under different MC. Additionally, the fitted models of CT number-density and CT number-MC were established and validated for the heartwood and sapwood of P. tomentosa and P. massoniana. The methodological improvement has been described in detail regarding the established models, which are contrasted and discussed with previous models. The results showed that the CT number-density fitted models of the heartwood and sapwood of P. tomentosa and P. massoniana adopted the linear model: $$ D = k \times H + b $$, where D is the density, H is the CT number, k is the slope, and b is the intercept. R2 values obtained in the validation models were all higher than 0.98, indicating that the CT number-density fitted models can reliably predict wood density. The CT number-MC fitted models for the heartwood and sapwood of P. tomentosa and P. massoniana adopted the logarithmic model: $$ M = \ln ((a + b \times H)^{100} ) $$, where M is the MC, H is the CT number, and a and b are the correlation coefficients in the model. R2 values obtained in the validation models were all higher than 0.95, indicating that this model is valid for the accurate prediction of wood MC. The fitted model parameters of heartwood and sapwood indicated that the X-CT technology was effective for identifying the difference in density and MC of heartwood and sapwood. Therefore, it is feasible to use non-destructive testing technology when studying density and MC of heartwood and sapwood based on X-CT technology. The study results provide reference data for the non-destructive testing of wood properties and reasonable utilization.

Magnetic bamboo charcoal was one-pot synthesized and employed in the removal of methylene blue. The data indicated that three different oxidation states of iron (Fe3O4, FeO, and zero-valent iron) were generated under different pyrolytic temperatures, and the maximum specific surface area was 484.6 m2/g. Both physical adsorption and catalytic degradation of MBC with zero-valent iron exhibited more effective capability to decontaminate organic pollution, as the zero-valent iron acted as a Fenton-like catalyst under aerobic conditions. In addition, the obtained magnetic bamboo charcoal manifested the maximum absorption-degradation capacity of methylene blue which was 73.6 mg/g under the weakly acidic (pH=5) and high temperature (60 °C) conditions, which broadened the applications as compared with the classic Fenton catalyst.

Acidified sodium chlorite (NaClO2) and sodium hydroxide (NaOH) solutions were successfully used to eliminate lignin and hemicellulose, respectively, from isolated bamboo fibers to investigate their microstructures, composition and micro-tensile properties in individual cellulose fibers. The results demonstrated that isolated fibers and chemically treated fibers clearly displayed different wrinkles, pores and microfibril aggregations on the cell wall surface. Field emission environmental scanning electron microscope images together with confocal scanning laser microscope measurements revealed that chemical treatments have a reduction effect on micro-tensile strength and modulus. Two methods of freeze-drying and air-drying produced varying interfaces and pores in microfibril aggregations and resulted in different tensile behavior. Notably, the reductions of Young’s modulus and tensile strength in freeze-drying (52.99 and 13.32%) fibers are larger than that (18.21 and 10.93%) in air-drying samples. These results suggest that most fractures occur in the weak interspaces or pores that are caused by the loss of matrix materials during chemical treatments.

We explored the discoloration of rattan cane using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). XPS analysis showed that after the cane was stained by Lasiodiplodia theobromae, carbon and oxygen elements and the ratio of oxygen to carbon decreased. Considering atomic binding, C1 and C4 contents increased, while C2 and C3 contents decreased, and the ratio of O2 to O1 decreased sharply. The relative contents of lignin, cellulose and polysaccharides increased and new substances with low O2/O1 ratio occurred. FTIR analysis showed that the absorption peaks of O–H at 3346 cm−1, aliphatic C–H at 2921, 2853 and 1464 cm−1, and C=O at 1723 cm−1, were characteristic peaks of fungal melanin intensified, indicating that cane discoloration was primarily caused by fungal melanin. The absorption peaks characterizing cellulose and lignin like polysaccharides at 800 cm−1, C–H at 1374 cm−1, C–O at 1058 and 1038 cm−1, phenolic hydroxyl at 1245 cm−1, aromatic ether bonds at 1270 cm−1, carbon skeleton at 1608 cm−1 and benzene ring at 1500 cm−1 were enhanced since the fungus mainly consumed the extractives in cane cell lumens and the main composition content increased relatively. Regardless of the discoloration caused by natural fungi or inoculated fungi, the discoloring feature and composition changes were identical except that the fungus-inoculated cane had more melanin.

How to design a simple and scalable procedure for manufacturing multifunctional carbon-based nanoparticles using lignocellulosic biomass directly is a challenging task. Based on the green chemistry concept, we developed a novel one-pot solution-phase reaction to prepare carbon-encapsulated magnetic nano-Fe3O4 particles (Fe3O4@C) with a tunable structure and composition through the hydrothermal carbonization (HTC) of Fe2+/Fe3+ loaded rattan holocelluloses pretreated with ionic liquids (EmimAc and AmimCl). The detailed characterization results indicated that the Fe3O4@C synthesized from the holocelluloses pretreated with ionic liquids (ILs) under alkaline conditions tends to have a higher saturation magnetization, probably due to the increased iron ions loading. Moreover, increasing the HTC temperature led to an increased abundance of hydroxyl groups on the surface of the synthesized particles and an elevated saturation magnetization. When EmimAc-treated holocelluloses were used as the carbon precursors, well-encapsulated Fe3O4@C nanoparticles were obtained with a maximum saturation magnetization of 42.6 emu/g. This synthetic strategy, coupled with the structure of the iron carbide-based composite and the proposed mechanism, may open a new avenue for the development of carbon-encapsulated iron oxide-based magnetic nanoparticles.

With no effective treatments available for most pancreatic cancer patients, pancreatic cancer continues to be one of the most difficult malignancies to treat. Oncolytic virus mediated-gene therapy has exhibited ubiquitous antitumor potential. In this study, we constructed a novel oncolytic vaccinia virus harboring the inhibitor of growth family member 4 gene (VV-ING4) to investigate its therapeutic efficacy alone or in combination with gemcitabine against pancreatic cancer cells in vitro and in vivo. ING4 expression was determined via quantitative real-time polymerase chain reaction (qPCR) and western blot. The cytotoxicity of VV-ING4 was measured using a cell proliferation assay. Both flow cytometry and western blot were applied to analyze the cell cycle and apoptosis. Furthermore, the combination inhibitory effect of VV-ING4 and gemcitabine was assessed using Chou-Talalay analysis in vitro and a BLAB/c mice model in vivo. We found that VV-ING4 significantly increases ING4 expression, displayed greater cytotoxic efficiency, and induced pancreatic cancer cell apoptosis and G2/M phase arrest. Additionally, the combination of VV-ING4 and gemcitabine synergistically effect in vitro and in vivo. Taken together, our data implicate VV-ING4 as a conceivable pancreatic cancer therapeutic candidate alone or in combination with gemcitabine.

The core-shell structure of carbon encapsulated magnetic nanoparticles (CEMNs) displays unique properties. Enhancing the magnetization of iron core, in parallel, improving the encapsulation of carbon shell are the two major challenges in the synthesis of CEMNs. Inspired by efficient cellulose-dissolving system, carbon encapsulated magnetic nano-Fe3O4 particles (Fe3O4@C) with ∼10.0nm Fe3O4 cores and 1.9-3.3nm carbon shell, were successfully one-pot synthesized via a novel hydrothermal carbonization (HTC) process. The dissolving process in ionic liquids ([Emim]Ac and [Amim]Cl) completely cleaved the intra- and intermolecular H-bonds in cellulose, and favored the incorporation of Fe3O4 nanoparticles into the cellulose H-bonds systems during the regeneration process. Some stable linkages were formed in Fe3O4@C, taking Fe3O4 nanoparticles as a structure guiding agent. The morphology and properties of Fe3O4@C depended strongly on the type of carbon precursors and pyrolysis temperature. Well encapsulated nanostructure was obtained at HTC temperature 280°C, when [Emim]Ac-treated holocellulose was used as the carbon source. Meanwhile, the thickness of the amorphous shell and magnetization increased with HTC temperature. More importantly, a novel elements for understanding the growth mechanism for the Fe3O4@C composite under HTC conditions was proposed.

Rattan-based silicon carbide (R-SiC) ceramics, R-SiCSiO2 and R-SiCSi, were successfully prepared from silica (SiO2) sol and silicon (Si) powder, respectively. The rattan powder was impregnated, respectively, with SiO2 sol at ambient temperature and liquid melt-Si at high temperature. This was followed by one-step direct pyrolysis at 1500 °C under an argon (Ar) atmosphere. The final SiC samples were analyzed using mass analysis, X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), energy dispersive X-ray analysis (EDAX), and nitrogen (N2) physisorption techniques. Experimental results showed that the mass residual of R-SiCSi (42.56 wt%) was almost equal to R-SiCSiO2 (42.45 wt%). However, R-SiCSiO2 had a higher yield of SiC, a higher specific surface area and a more intact porous morphology preserved from the rattan biomass. In addition, some rod-like SiC whiskers and tablet-like SiC particles were found in R-SiCSiO2. By comparison, R-SiCSi had a large amount of unreacted Si, as well as certain amount of SiC and unreacted C. Thus, it can be concluded that SiO2 sols are more appropriate for use in preparation of SiC from rattan, whatever the porous microstructure, yield, and purity of SiC.

The effects of chemical treatments (H2O2 + CH3COOH, acidified NaClO2, and NaOH) and freeze-drying on bamboo fibers were studied at a submicron level, to characterize chemical and mechanical changes to the secondary cell wall. Specifically, a field emission environmental scanning electron microscope (FE-ESEM) and imaging fourier transform infrared spectroscopy (FTIR) were used to demonstrate degradation in morphology and molecular structure, and nanoindentation was used to track changes in micromechanical properties. The results showed that cellular structures after chemical treatments clearly displayed wrinkles, pores, and microfibrils. The decreased bands at 1508 cm-1 and 1426 cm−1 showed that lignin was degraded on treatment of H2O2 + CH3COOH and acidified NaClO2, which directly resulted in a decrease in hardness (H) in the secondary cell wall for treated fibers. In addition, a diminishing peak at 1733 cm−1 caused by NaOH solution indicated that hemicellulose was seriously degraded. It resulted in a decreased modulus (E r) by 13.71 % in bamboo fibers, while no obvious reduction was observed in the first two steps.

To the best of our knowledge, there is the lack of sufficient information concerning bamboo pellets. In the preliminary research, bamboo pellets showed a low bulk density which could not meet requirement of Pellet Fuels Institute Standard Specification for Residential/Commercial Densified (PFI). To improve its bulk density, pellets were manufactured using mixtures of bamboo and pine particles and the properties were investigated. It was found that adding pine particles to bamboo particles was an effective way to improve bulk density of bamboo pellets. When adding 40% pine particles to bamboo particles, bulk density of pellets increased from 0.54 g/cm3 to 0.60 g/cm3, meeting grade requirement of PFI utility. Furthermore, length, diameter and inorganic ash of pellets were also improved. Fine contents of pellets decreased from premium grade to utility grade according to PFI standard. Net calorific value also slightly decreased but it could meet the requirement of DIN 51731 (>17,500 J/g). The effect of this interaction on bulk density, inorganic ash, Net calorific value, combustion rate and heat release rate were significant. The results from this research will be very helpful to develop bamboo pellets and provide guidelines for further research.

This study aims to evaluate the mechanical properties of rattan/polymer composites prepared by polymerization with methyl methacrylate (MMA). The P. kerrana rattan samples were impregnated in a vacuum system and polymerized in an oven at 60 °C for 8 h, using 0.5 wt.% of azobisisobutyronitrile as a catalyst. The macro-mechanical properties of the treated and untreated samples were analyzed. The bending modulus and strength of the treated rattan increased by 206% and 215%, respectively. Additionally, the compressive modulus and strength increased by 109% and 107%, compared to untreated rattan. Scanning electron microscopy (SEM) images showed that MMA penetrated the cell lumen. Furthermore, Fourier transform infrared spectroscopy (FTIR) analysis revealed that MMA diffused into the parenchyma and vessels, but it was not found in the fiber wall. Thus, it can be inferred that the improvement in the mechanical properties of treated rattan was mainly caused by the strengthened parenchyma and vessels. Modification with MMA was shown to be an effective way to enhance the macro-mechanical properties of P. kerrana.

This study was carried out to investigate combustion characteristics of moso bamboo, including outer layer (OB), middle layer (MB) and inner layer (IB) and bamboo leaves (BL), respectively. The results showed that combustion characteristics of moso bamboo were similar to other biomass materials. There were two separate peaks in the combustion process; the first peak corresponding to combustion of volatile matters and the second peak corresponding to combustion of biochar. Compared to OB, MB and IB, BL had a worse fuel quality with higher H/C and O/C value, N and S content, ash content and lower combustion efficiency. Furthermore, BL had a higher slagging index and MB had a higher fouling index. These combustion characteristics of bamboo should be taken into consideration to efficiently design and operate the combustion systems when directly used for fuel production.

Bamboo is a composite material reinforced axially by fibers called vascular bundles. In this paper, the mechanical stripping method was used to isolate vascular bundles from moso bamboo (Phyllostachys edulis), China’s most important commercial bamboo species. The paper focuses on analyzing the suitability of this method for measuring the mechanical properties of single vascular bundles with respect to their location within a bamboo culm. Using a confocal laser scanning microscope (CLSM) and video extensometry testing technique, we found that the tensile mechanical properties of vascular bundle can be determined with great accuracy. The method relies on mechanical stripping to prepare samples at a length scale from individual bamboo, which traditionally increases the difficulty of conducting tests. Therefore, to determine the elastic modulus of vascular bundle material, video extensometry was used for efficient strain detection in tensile experiments. This type of sample preparation minimizes the usual problems encountered when mounting samples. The cross-sectional area of the vascular bundle was determined by CLSM measurement using an ultramicrotome as a cutting tool. Applying this method, the elastic modulus and tensile strength of the vascular bundle of moso bamboo were measured to be ~44.67 GPa and ~709.96 MPa, respectively. It is noteworthy that the tensile mechanical properties of the fibrous sheath areas are higher than those observed over the whole area.

Structural organization of the plant cell wall is a key parameter for understanding anisotropic plant growth and mechanical behavior. Four imaging platforms were used to investigate the cell wall architecture ofMiscanthus sinensiscv. internode tissue. Using transmission electron microscopy with potassium permanganate, we found a great degree of inhomogeneity in the layering structure (4–9 layers) of the sclerenchymatic fiber (Sf). However, the xylem vessel showed a single layer. Atomic force microscopy images revealed that the cellulose microfibrils (Mfs) deposited in the primary wall of the protoxylem vessel (Pxv) were disordered, while the secondary wall was composed of Mfs oriented in parallel in the cross and longitudinal section. Furthermore, Raman spectroscopy images indicated no variation in the Mf orientation of Pxv and the Mfs in Pxv were oriented more perpendicular to the cell axis than that of Sfs. Based on the integrated results, we have proposed an architectural model of Pxv composed of two layers: an outermost primary wall composed of a meshwork of Mfs and inner secondary wall containing parallel Mfs. This proposed model will support future ultrastructural analysis of plant cell walls in heterogeneous tissues, an area of increasing scientific interest particularly for liquid biofuel processing.

Bamboo is a type of biomass material and has great potential as a bio-energy resource of the future in China. Some properties of bamboo pellets, length, diameter, moisture content (MC), particle density, bulk density, durability, fine content, ash, gross calorific value, combustion rate and heat release rate, were determined and the effects of MC and particle size (PS) on these properties were investigated in this research. The results showed that bamboo pellets will be the proposed new biomass solid fuel and have the potential to be developed as commercial pellets. All properties of bamboo pellets met the requirement of Pellet Fuels Institute Standard Specification for Residential/Commercial Densified Fuel. The gross calorific value of bamboo pellets also met the minimum requirement for making commercial pellets according to DIN 51731 (>17,500 J/g). The effects of MC on length, diameter, MC, particle density and bulk density were significant at p = 0.05. There were no significant differences between PS and all properties of bamboo pellets. Due to higher MC and larger PS, bamboo pellets exhibited higher combustion rates and heat release rates. This research represents an initial stage in the study of bamboo pellets, and its objectives provide guidelines for further research.

Rice straw pellets are the main type of biomass solid fuel and have great potential as a bioenergy resource of the future in China. But it also showed important problems because of its high content of ashes and its low gross calorific value, reducing the possibility to be used in domestic heating. It was certified that mixing different types of biomass materials was helpful to improve the properties of pellets. To improve properties of rice straw pellets and investigate the effect of mixing bamboo and rice straw on the pellet properties, some properties of pellets, manufactured using different mixing ratio of bamboo and rice straw particles, were determined in this research. It can be concluded from this research that physical properties of all pellets meet the requirements of Pellet Fuels Institute Standard Specification for Residential/Commercial Densified except for bulk density of pellets, manufactured using mixing ratio (≤3:2) of bamboo and rice straw. The inorganic ash and gross calorific value of rice straw pellets cannot meet the requirement of Pellet Fuels Institute Standard Specification for Residential/Commercial Densified (8.0%) and the minimum requirement for making commercial pellets of DIN 51731 (>17,500 J/g) . Both properties are improved through mixing bamboo particles and rice straw particles. It is significant that inorganic ash content and gross calorific value of pellets, manufactured using mixing ratio (≥3:2) of bamboo and rice straw, were lower than 8.0% and higher than 17,500 J/g, respectively. This also shows that mixing different biomass materials is an effective way to optimize properties of biomass solid fuel. All pellets after improvement are proposed as biomass solid fuel and have the potential to be developed as commercial pellets on an industrial scale in China.

Bamboo is a biomass material and has great potential as a bio-energy resource of the future in China. Bamboo pellets were successfully manufactured using a laboratory pellet mill in preliminary work. This study was therefore carried out to investigate the effect of carbonization conditions (temperature and time) on properties of bamboo pellets and to evaluate product properties. It was concluded that carbonization conditions affected the properties of bamboo pellets. The effects of carbonization temperature on some properties such as unit mass loss, pellet absorption, bulk density, unit density, gross calorific value and combustion rate, were significant at p = 0.05. But there were not significant differences between carbonization time and all properties of bamboo pellets. After being carbonized, the properties of bamboo pellets, such as pellet absorption, durability, fine, gross calorific value, combustion rate and heat release rate, were improved. All properties of carbonized pellets meet the requirement of the Pellet Fuels Institute Standard Specification for Residential/Commercial Densified and the gross calorific value also meets the minimum requirement for making commercial pellets of DIN 51731 (>17,500 J/g) even though the properties of carbonized pellets, such as bulk density, unit density and inorganic ash, had poor quality compared with untreated pellets. Carbonized bamboo pellets are the proposed new biomass solid fuel and have the potential to be developed as commercial pellets.

A novel bamboo bundle laminated composite with a corrugated structure, denoted BCLC, was developed. The objective of this work was to investigate how the three-dimensional shrinkage and swelling properties are affected by the shape of the composites. Three types of stacking sequences were designed and their shrinkage and swelling performances were compared. A shape parameter, K, was used to quantify the corrugated effect on the shrinkage or swelling in three directions. The dimensional stability of the BCLC was significantly different among the three directions of the composites, and it was affected by the stacking sequence of the bamboo bundles. Shrinkage ratio, swelling ratio, and drying coefficient were significantly greater in the thickness direction compared with those in the length or width directions. Corrugated effect in response to width and thickness direction was positive, vs. negative to length. The absolute value of shape parameter was largest in the length direction and smallest in the thick...

Bamboo is a potential major bio-energy resource. Tests were carried out to compare and evaluate the property of bamboo and rice straw pellets, rice straw being the other main source of biomass solid fuel in China. All physical properties of untreated bamboo pellets (UBP), untreated rice straw pellets (URP), carbonized bamboo pellets (CBP), and carbonized rice straw pellets (CRP) met the requirements of Pellet Fuels Institute Standard Specification for Residential/Commercial Densified including dimension, density, and strength. The inorganic ash (15.94 %) and gross heat value (15375 J/g) of rice straw pellets could not meet the requirement of Pellet Fuels Institute Standard Specification for Residential/Commercial Densified (≤6.0% for PFI Utility) and the minimum requirement for making commercial pellets of DIN 51731 (>17500 J/g), respectively. Rice straw pellets have been a main type of biomass solid fuel and widely used. Bamboo pellets have better combustion properties compared with rice straw pellets. It is confirmed that bamboo pellets have great potential as biomass solid fuel, especially with respect to development of commercial pellets on an industrial scale in China. The information provided by this research is useful for development and utilization of bamboo resource and pellets.

On the concept of biorefinery, hemicellulosic and lignin fractions were isolated from white-rot fungal Trametes velutina D10149 biodegraded poplar, and the structural modification was elucidated in detail according to the different incubation duration. Transversal-section Raman images showed that the fiber secondary walls were preferentially degraded, whereas the compound middle lamellae, including the cell corner regions, were mainly intact after 16 weeks incubation. More importantly, lignin and carbohydrates were simultaneously removed within the fiber secondary wall. From wet chemistry analysis, the yields and structural properties for both hemicellulosic and lignin fractions were not significantly altered. The synergistic effect of ligninolytic system finally obviously appeared after 16 weeks incubation, evidenced by the remarkable decrement of hemicellulose and lignin molecular weights. Additionally, the preferential degradation of S units in lignin biomacromolecule was further confirmed by composition analysis of cell wall phenolics and the integration of 2D NMR correlations in the aromatic region.

The moisture dependence of different mechanical properties of bamboo has not been fully understood. In this work, the longitudinal tensile modulus, bending modulus, and compressive and shearing strength parallel to the grain were determined for bamboo of ages 0.5, 1.5, 2.5, and 4.5 years under different moisture contents (MC) to elucidate the sensitivity of different mechanical properties of bamboo to MC change. The results showed that the four mechanical properties of bamboo respond differently to MC changes. Compressive and shearing strength parallel to the grain were most sensitive to MC changes, followed by longitudinal tensile modulus, then bending modulus. This can be partially explained by the different responses of the three main components in the plant cell wall to MC change. For tensile modulus and bending modulus, the effect of bamboo age on the sensitivity to MC change was insignificant, while young bamboo (0.5 years old) was more sensitive to MC changes for shear strength and less sensitive for compression strength than older bamboo.

Moso bamboo (Phyllostachys pubescens) and sinocalamus affinis (Phyllostachys heterocycla) were used in the research. Thermogravimetry (TG), a combination of TG and Fourier transform infrared spectrometer (TG–FTIR), X-ray diffraction (XRD), and differential thermal analysis (DTA) were used to investigate thermal decomposition of bamboo. The calorific value and smoke release process of both bamboos were also tested, respectively. The results from TG indicated that degradation process of sinocalamus affinis and moso bamboo was similar, but their degradation temperatures were different. The main decomposition occurred in the second step and about 68.70 and 64.63% masses degraded for sinocalamus affinis and moso bamboo, whose temperature of maximum mass loss was 319 and 339 °C, respectively. DTA curve showed that the thermal decomposition of both bamboos was an absorbance heat process. TG–FTIR analysis showed that the main pyrolysis products of both bamboos were similar, including absorbed water (H2O), methane gas (CH4), carbon dioxide (CO2), acids and aldehydes, ammonia gas (NH3). The calorific value of moso bamboo (19,291 J g−1 K−1) was higher than that of sinocalamus affinis (18,082 J g−1 K−1). The initial time of smoke release process of moso bamboo was later, and its maximum smoke density was higher than that of sinocalamus affinis. The difference was probably attributed to different compositions and structure of sinocalamus affinis and moso bamboo. The results from this research are very helpful to better design manufacturing process of bio-energy, made from bamboo, by gasification and pyrolysis methods.