Volume 11 Issue 1

A multifunctional fluorescent polymer based on coumarin (MFPC) was synthesized using a four-step synthetic route. To obtain the target compound, 7-amino-4-methylcoumarin, coumarin fluorescent monomer (CFM), and ultraviolet absorber monomer (UVAM) were prepared. By the reaction of CFM, UVAM, trimethyl-2-methacroyloxyethylammonium chloride (DMC), and acrylamide (AM) as a linker, a new multifunctional fluorescent polymer was synthesized. The structure of the MFPC was characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H-NMR) spectroscopies. The optical properties of MFPC were measured by ultraviolet-visible (UV-vis) and fluorescence spectroscopies, in aqueous solution. The integration effect between MFPC and paper was tested by scanning electron microscopy. The application performance of MFPC on paper was evaluated by measuring the surface strength, smoothness, and whiteness using the printability tester and the UV accelerated aging test. Results indicated that the MFPC had good solubility in water. It also exhibited a positive effect on the light stability and surface strength of paper as a light stabilizer, fluorescent brightener, and surface sizing agent.

The unique physico-chemical properties of silver nanoparticles (Ag NPs) have opened up the opportunity for their use in many promising physico-chemical and biomedical applications. In this study, an economically feasible approach to green synthesis of silver nanoparticles (Ag NPs) is described using hemicellulose from bamboo. Simultaneously, glucose was used as the reducing agent, and distilled water was used as the reaction medium. UV-vis spectroscopy and transmission electron microscopy were used to investigate the surface plasmon behavior, morphology, and particle size of the Ag NPs. Hemicellulose alone could not reduce Ag+ to Ag0. The formation rate of the nanoparticles was accelerated when high amounts of glucose were added. Small particle sizes were obtained when high concentrations of hemicellulose were used. The stability of the Ag NPs synthesized using different concentrations of hemicellulose from 0.5 mg/mL to 8.0 mg/mL was also evaluated. Higher initial hemicellulose concentrations produced more stable Ag NPs. The average particle sizes of the NPs after storing for 160 days at 4 °C were still smaller than 10 nm when the initial hemicellulose concentrations were 6.0 and 8.0 mg/mL.

A new approach for micronutrient fertilizer biocomponent production based on blackcurrant seeds is presented. Blackcurrant seeds constitute a by-product from the production of jellies, jams, and juices. New environmental-friendly fertilizers with micronutrients were produced in the pilot plant as alternative sustainable fertilizers to conventional options. Post-extraction residues, obtained after supercritical CO2 extraction was conducted on blackcurrant seeds, were used. In each process, 15 kg of biosorbent was used. Good sorption capacity was achieved (6.48 mg/g for Zn(II), 13.9 mg/g for Cu(II) and 5.88 mg/g for Mn (II)). The adsorption kinetics was described using different kinetic models; the most suitable were the Nelson-Yoon and Thomas models. The new preparation has application-friendly form (micro-granules) and is nontoxic. For a dose of 2.5 kg of zinc, 1 kg of manganese, and 0.5 kg of copper per hectare (often used in vegetable fertilization), approximately 600 kg of mixed end product is required. The cost of fertilization with current scale technology will be about four times higher than that of conventional technology (including depreciation of equipment), but with process scale-up, it is possible to reduce costs even twice over.

Bamboo, among other natural plants, has a special structure, with different characterization along the culms and between species. In this study, the thermal stabilities of four bamboo species, named Dendrocalamus pendulus (DP), Dendrocalamus asper (DA), Gigantochloa levis (GL), and Gigantochloa scortechinii (GS), were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) under a nitrogen atmosphere. Each species was divided into three different portions: bottom, middle, and top, and fibres were manually extracted from the specified sections of each species. The thermal analysis of extracted bamboo fibres indicated that the thermal degradation behaviour of each bamboo species varied from bottom to top and between species. However, these variations were lower in DA species compared to GS, GL, and DP, because of minor differences between lignocellulosic components of its three portions. The top and middle portions of the four species degraded at a higher temperature range (314 to 379 °C) than the bottom portions. The results of this study suggest that DA and GS species, according to their thermal stabilities, are most suitable for use as reinforcement in composite materials.

Merbau wood has been widely used in outdoor applications. However, it has a disadvantage in that its water-soluble extractives readily leach out and stain adjacent materials. Heat treatment is an efficient technique to solve this problem. In this study, the effects of heat treatment on the durability of merbau heartwood were investigated. Merbau heartwood blocks with and without heat treatment were exposed to subterranean termites (Coptotermes formosanus) according to ASTM D3345 (2008), and to brown-rot fungus (Gloeophyllum trabeum) and white-rot fungus (Trametes versicolor) according to ASTM D1413 (2007). The effect of heat treatment on the chemical changes in merbau heartwood and its extracts were investigated by means of Fourier transform infrared spectroscopy (FTIR) and gas chromatography – mass spectrometer (GC/MS). The results show that the extraction yields of merbau heartwood with heat treatment using various solvents significantly decreased. However, termite resistance and fungal resistance of merbau heartwood with and without heat treatment showed no obvious difference. FTIR spectra in the fingerprint region of merbau heartwood and its ethanol-benzene extracts did not show any significant difference between heat-treated and untreated samples. More constituents were identified from the ethanol-benzene extracts of merbau heartwood with heat treatment by means of GC/MS compared to those identified from the ethanol-benzene extracts of untreated merbau heartwood.

This paper investigates the financial aspects of small and medium enterprises (SMEs) in the Slovak wood-processing industry. The aim of the survey was to determine the level of understanding and implementation of financial controlling, and to identify its potential for future implementation. The survey revealed a low level of understanding and implementation of this tool in Slovak wood-processing SMEs, because the use of all analyzed instruments of financial controlling was in small enterprises in a range of 15% and in medium-sized enterprises up to 40%. However, medium-sized enterprises were substantially more equipped than small enterprises at applying and recognizing the benefits of financial controlling. Based on the results of this research, the framework for a standardized model of financial controlling for Slovak wood-processing SMEs was proposed, as a practical way of improving company performance models.

The effectiveness of sludge inocula from a municipal carrousel oxidation ditch wastewater treatment plant was studied for both batch and semi-continuous anaerobic digestion (AD) of cassava pulp. In 1.25-L batch experiments, the following sludge inocula were used: I1 sludge from the hydrolysis acidification tank pre-acclimated with cassava pulp; I2, predigested sludge from the hydrolysis acidification tank; and I3, predigested sludge from the gravity thickening tank. In 1.0-L semi-continuous tests, mesophilic AD of cassava pulp inoculated with I3 was carried out at organic matter loading rates (OLRs) of 1.5 to 12.5 kg volatile solids (VS)/(m3 d), whereas 1.5 to 18.0 kgVS/(m3 d) was used for thermophilic AD. For batch operations, all sludge types could be used as the inoculum for the mesophilic AD of cassava pulp, whereas only I1 was used for thermophilic AD. The maximum specific methane yields were 0.333 and 0.395 m3/kgVSadded, respectively, for mesophilic and thermophilic batch digestion with I1. During semi-continuous AD of cassava pulp inoculated with I3, high specific methane yields of 0.334 to 0.336 m3/kgVSadded were obtained under both mesophilic and thermophilic conditions. For thermophilic AD of cassava pulp with sludge inocula, the range of optimum OLR was 2.5 to 15.0 kgVS/(m3 d), and that was 2.5 to 8.7 kgVS/(m3 d) for mesophilic AD.

The dyeing properties of basswood veneer treated by dichlorotriazine reactive dye in a dip dyeing method were evaluated. The effects of dye concentration, dyeing temperature and time, volume ratio, and dyeing agent were observed relative to the dye-uptake and K/S, using gray correlation analysis. Results showed that various dip dyeing factors had remarkable influences on dye-uptake and K/S, especially dyeing temperature and volume ratio. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) results indicated that reactive dyes were successfully combined with basswood and diffused into the wood fiber lumens and ray cells. Furthermore, thermogravimetric analysis (TGA) demonstrated that the residue of dyed veneer was higher than undyed, and the temperature at maximum degradation rate of dyed and undyed veneer was different.

As an immerging lignocellulose pretreatment strategy, cellulose solvent-based pretreatment can break down inter- and intra-molecular hydrogen bonds and disrupt the rigid structure of cellulose. Two cellulose solvent pretreatments were examined and compared in this study: NaOH/urea and concentrated phosphoric acid. Pretreated corn stover substrates were characterized by optical microscopy, confocal laser scanning microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and chemical analyses. It was found that both alkaline- and acid-based cellulose solvent pretreatments can disrupt cell wall structures and cause partial dissolution of the cell wall components. The results indicated that the alkaline-based cellulose solvent was more effective at removing lignin as compared with the phosphoric acid-based cellulose solvent. The initial enzymatic saccharification rate of corn stover pretreated by alkaline-based cellulose solvent was greatly enhanced; complete saccharification of the glucans was achieved within 24 h at an enzyme loading of 15 filter paper units (FPU)/g substrate. The enzymatic digestibility of corn stover pretreated by phosphoric acid was lower than that of the alkaline-based system; this was probably caused by the presence of a high concentration of lignin.

The aim of this study was to understand the microscopic characteristics of the bamboo bonding interface with phenol formaldehyde resin modified with larch thanaka and urea (PTUF) and its effect on the shear strength of two-ply bamboo laminated lumber. Bleached and carbonized bamboo strips were used, and two assembly patterns (outer-to-outer and inner-to-inner) were adopted to make two-ply bamboo laminated lumber with PTUF. The microstructure of the bonding interface and the bond-line thickness were investigated using a scanning electron microscope. The average depth and effective depth of PTUF on bamboo surfaces were evaluated by fluorescent microscopy characterization. The shear strength of two-ply bamboo laminated lumber was also examined. The results revealed a shallow depth of penetration of PTUF into the bamboo surface that was distributed primarily in the broken cell cavities formed during preparation, as well as between the cell walls. When the assembly pattern was inner-to-inner, the depth of penetration and bond-line thickness were higher, but the shear strength was lower than that of the outer-to-outer pattern. The carbonized bamboo laminated lumber provided a greater resin penetration and bond-line thickness, but lower shear strength, than the bleached bamboo laminated lumber.