Volume 10 Issue 1

The chemical composition of the wax layer and green epidermis at the surface of giant bamboo (Dendrocalamus giganteus Munro) culms were conveniently analyzed through the diffuse reflectance infrared Fourier transform (DRIFT) with Si-Carb sampling technique. Results from the radial lignin content profiling of giant bamboo showed that the lignin content in the middle layer was lower than the layers either from the inner or outer culms. As for the longitudinal depth profiling, the lignin contents of bamboo culms increased gradually from the top toward base portion. The distribution of growth strains in the radial direction of giant bamboo culm was investigated by the kerf method with strain gauges. The longitudinal tensile strains in various positions of giant bamboo culm were found to decrease in the order of the middle layer, the outer layer, and the inner layer. The tensile strains of different layers in the radial direction of giant bamboo culm correlate with their lignin content. The highest tensile strain on the middle layer of the bamboo culm was associated with the lowest lignin content. These results provided experimental evidence in the relationship between longitudinal tensile strain and lignin content of bamboo culm.

Mesoporous nanocrystalline tetragonal zirconias were successfully synthesized through a hydrothermal method using a novel bioresource-derived quaternary ammonium salt, dehydroabietyltrimethyl ammonium bromine (DTAB), as a templating agent. The templating agent provides a surface area (242.02 m2/g), high pore volume (0.53 cm3/g), and large average pore diameter (7.65 nm), which suggests that DTAB is a good candidate for mesostructure synthesis. The hydrothermal treatments give the materials improved thermal stabilities because of the generation of tetragonal nanocrystallites that are more stable than the bulk amorphous ones in the hydrothermal process. However, because of the absence of stabilizers, the sizes of the crystallites of the as-synthesized sample increase gradually with increasing calcination temperature. As the crystalline size of the sample rises to 25 nm, the nanocrystallites become too large to integrate well together, causing the well-organized mesostructure to collapse.

Spruce chemithermomechanical pulp was treated with a laccase mediator system (LMS) and alkaline H2O2, and the whiteness and dye removal index of the long fibres fraction and fines fraction were compared. The long fibres fraction and fines fraction were treated separately with a LMS, and their whitenesses and strengths were tested. The results indicated that the lignin and extractives contents of the fines fraction were higher than that of the long fibres. Because of the strong adsorption capacity and higher reactive efficiency, the optimal laccase dosage of the fines fraction was lower than that of the long fibres. In the process of treatment using a LMS and alkaline H2O2, at the same laccase dosage, separate treatment of the long fibres fraction and fines fraction could improve pulp whiteness and pulp strength.

This study investigated the pull off strengths of various laminated medium density fiberboards (MDFs). The surface roughness of the MDF, adhesive type, and veneer type were all studied. Polyvinylacetate (PVAc), urea formaldehyde (UF), and gluten were used as the adhesives for beech, pine, and oak veneers. There were a total of 216 experimental specimens that were tested according to the principles specified in the TS 5339 (1987) standard. According to the statistical analyses of the data obtained from the tests, surface roughness, veneer species, and adhesive type all affected the pull-off strength of the laminated MDF. The highest pull-off strength (2.88 N/mm2) was obtained with the MDF unsanded with 120-grit abrasive and laminated with PVAc adhesive and pine veneer. The lowest pull-off strength (1.60 N/mm2) was obtained with the unsanded MDF laminated with PVAc adhesive and oak veneer.

After programmed cell death (PCD), heartwood formation, storage, and processing, wood DNA degradation occurs to varying degrees. The concentration and distribution of nuclei and plastids in xylem cells of Cunninghamia lanceolata and Aquilaria sinensis, treated under different conditions of processing and storing, were studied by analyzing the distribution frequency, area, and signal intensity, in specimens that had been stained with aceto-carmine, DAPI, and I2-KI. Most of the nuclei and plastids were present in the ray cells, and a small quantity of nuclei and plastids were present in the axial parenchyma cells. There was an indication that the concentration of the remaining nuclei and plastids in the xylem cells was mainly affected by the xylem heartwood formation, storage time, and temperature. The nuclei and plastids content of the sapwood was greater than that of the heartwood. However, the nuclei and plastids content of the fresh wood was greater than that of the processed and stored wood. An estimation of the quantity of nuclei and plastids using staining methods could provide a direct basis for the appropriate selection of a procedure for DNA extraction.

A safe microorganism (class 1), Paenibacillus polymyxa, was used for 2,3-butanediol and acetoin production, which could make the fermentation process cheaper and less complex. It showed a broad substrate spectrum, such as mannose, galactose, cellobiose, glycerol, the mixture of glucose and xylose, and the mixture of glucose and cellobiose. In addition, the strain can utilize highly concentrated glucose that was obtained by enzymatic hydrolysis of ionic liquid-pretreated cellulose. With a 15% initial cellulose consistency, the final glucose concentration was 109.5 g/L with 65.7% glucose yield. Without any treatment, the hydrolysate was successfully used to produce 2,3-butanediol and acetoin with a yield of 81.7% and a productivity of 0.7 g/(L·h) by Paenibacillus polymyxa. Higher concentration and higher productivity with relatively high yield, compared with previous works by acid hydrolysis, of 2,3-butanediol and acetoin were achieved. All these novel improvements offer significant opportunities to further decrease the cost of large-scale 2,3-butanediol and acetoin production.

A series of laboratory incubation experiments was conducted to evaluate the effect of biochar application on the efficacy of the nitrification inhibitor (NI) dicyandiamide (DCD) in Cambisol (pH 7.14) and Latosol (pH 4.83). The feedstocks (eucalyptus wood, coconut coir, and rice straw), pyrolysis temperatures (350, 500, and 650 ˚C), and application rates (0.5, 1.0, 2.5, and 5.0% of 200 g soil) were identified as influential factors. The results showed that biochar could significantly reduce the effectiveness of DCD on nitrification inhibition. Biochar produced from eucalyptus wood with a large surface area (426.4 m2 g−1) had the strongest ability to reduce the inhibitory effect of DCD in nearly neutral Cambisol, while biochar from rice straw with a high pH had the greatest influence on acidic Latosol. Increasing pyrolysis temperature and application rates can strengthen the ability of biochar to reduce the inhibitory effect of DCD. Generally, the decrease of the DCD nitrification inhibitory effect on nearly neutral soil was controlled by the surface area of the applied biochar; meanwhile, the rise of soil pH caused by biochar application was also an important influencing factor in acid soil.

Four organic Lewis acids, samarium(III), aluminum(III), yttrium(III), and indium(III) trifluoromethanesulfonates were combined with four organic Brønsted acids, benzenesulfonic, toluene-p-sulfonic, trichloroacetic, and oxalic acids to synergistically catalyze the decomposition of glucose to produce levulinic acid (LA). The combination of aluminum trifluoro-methanesulfonate (Al(CF3SO3)3) and oxalic acid (H2C2O4) exhibited a strong synergic activity for the decomposition of glucose to LA. The effects of the mole fraction of Al(CF3SO3)3 in the Al(CF3SO3)3-H2C2O4 system on the decompositions of glucose, fructose, and 5-hydroxymethylfurfural (5-HMF) were investigated. The mixed-acid system showed the strongest synergic catalytic activity for glucose, fructose, and 5-HMF decompositions at the Al(CF3SO3)3 mole fraction of 0.33. The effect of temperature on the decomposition of glucose in the Al(CF3SO3)3-H2C2O4 system was also investigated. Based on the results obtained in this contribution and previous work, synergy in catalytic systems was demonstrated.

In this research, sugarcane bagasse cellulose, an abundant non-wood plant fibrous raw material from Guangxi, was the substrate, stearyl methacrylate was the monomer, and ammonium persulfate was the initiator used to prepare an economical environmental oil biosorbent named sugarcane bagasse cellulose-graft-polystearylmethacrylate (SBC-g-PSMA), which can be obtained through homogeneous graft copolymerization in the ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl). Confirmation of successful synthesis was rendered using various analytical tools, including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-Ray Diffraction (XRD). Furthermore, the effects of various reaction parameters on the sorption capacity were all evaluated. Optimum conditions for the synthesis process were obtained as follows: the mass ratio of the monomer to sugarcane bagasse cellulose was 4:1, and the initiator to sugarcane bagasse cellulose ratio was 1:10, with a reaction time of 2 h. Under the optimum conditions, the maximum sorption capacities of the SBC-g-PSMA for 0.2 wt% hydrocarbon (benzene, kerosene, and diesel) were 10.24 g/g, 9.76 g/g, and 9.74 g/g, respectively. The SBC-g-PSMA was light and hydrophobic. It is a selective oil absorption material, so it holds promise to be applied in the treatment of low concentration oily wastewater.

A water-soluble fraction of bamboo ranging from 9.2 to 23.5 wt% was obtained by hot-compressed water (HCW) treatment as the temperature increased from 140 to 180 °C. Both untreated and HCW-treated bamboo fibers (BF) were then compounded with polypropylene (PP), either with or without the addition of 5 phr maleic anhydride-grafted PP (MAPP), to net a total BF content of 50, 30, or 10%. It was found that both the HCW treatment and the MAPP addition effectively improved the tensile properties of the composite. Furthermore, the re-compounding of 70/30 and 90/10 composites from a 50/50 master batch proved to be more effective in improving the tensile properties than the direct compounding of PP and non- or HCW-treated BF to the same composition.