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In this study, environmentally friendly and low-cost biomass materials were selected as wood flame retardants. Three polyelectrolyte flame-retardant coatings made from chitosan (CS), tea polyphenols (TP), soybean isolate protein (SPI), and banana peel powder (BBP) were constructed on wood surfaces by layer-by-layer (LBL) self-assembly. The results of SEM-EDS and FT-IR analyses confirmed the successful deposition of CS-TP, CS-SPI, and CS-BPP on the wood surface, and the content of N element increased. The TG results showed that the initial decomposition temperature and the maximum thermal decomposition temperature of the coated wood specimens decreased, while the char residue increased significantly. This is due to the earlier pyrolysis of CS-TP, CS-SPI, and CS-BBP. This shows that the three polyelectrolyte flame-retardant coatings can improve the thermal stability of wood. The combustion behavior of the wood specimen was observed by exposure to combustion; the coated wood could self-extinguish within a certain period of time after ignition, and the flame-retardant performance was improved to a certain extent. SEM and EDS characterization analyses of the carbon residue after combustion showed that the coated wood charcoal layer was denser, which could effectively block heat and combustible gas. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) is generally unavoidable during the production of fuel gases such as hydrogen (H2) from steam reformation and syngas composed of carbon monoxide (CO) and hydrogen (H2). Efficient separation of CO2 from these gases is highly important to improve the energetic utilization efficiency and prevent poisoning during specific applications. Metal–organic frameworks (MOFs), featuring ordered porous frameworks, high surface areas and tunable pore structures, are emerging porous materials utilized as solid adsorbents for efficient CO2 capture and separation. Furthermore, the construction of hierarchical MOFs with micropores and mesopores could further promote the dynamic separation processes, accelerating the diffusion of gas flow and exposing more adsorptive pore surface. Herein, we report a simple, efficient, one-pot template-mediated strategy to fabricate a hierarchically porous CuBTC (CuBTC-Water, BTC = 1,3,5-benzenetricarboxylate) for CO2 separation, which demonstrates abundant mesopores and the superb dynamic separation ability of CO2/N2. Therefore, CuBTC-Water demonstrated a CO2 uptake of 180.529 cm3 g−1 at 273 K and 1 bar, and 94.147 cm3 g−1 at 298 K and 1 bar, with selectivity for CO2/N2 mixtures as high as 56.547 at 273 K, much higher than microporous CuBTC. This work opens up a novel avenue to facilely fabricate hierarchically porous MOFs through one-pot synthesis for efficient dynamic CO2 separation. [ABSTRACT FROM AUTHOR]

Biorefinery is an excellent strategy to deal with the energy crisis and environmental pollution in the new age. Based on biorefinery, low-value biomass resources can be converted into various value-added products. Furfural is one value-added platform chemical from biomass resources, which has important applications in energy, medicine, chemical, and other fields. The industrial production of furfural has come out for nearly one century and is relatively mature nowadays. However, there are still some issues remain to be solved in the industrial production. In order to solve these problems, efforts have been paid on exploring new technologies and progresses. In this paper, the characteristics of furfural were introduced firstly, and the present situation and problems of furfural industrial production technology are summarized, including corrosion of equipment caused by acid catalysts, difficulty in catalyst recycling, water pollution and so on. Then, the research status and problems of furfural preparation by hydrolysis and pyrolysis and the characteristic of the microwave-assisted technology were carefully reviewed. Finally, the future development direction of furfural preparation technology was prospected. [ABSTRACT FROM AUTHOR]

ZnO nanorod array coatings were successfully synthesized on wood surfaces using a conventional hydrothermal (CHT) and a microwave-assisted hydrothermal (MWHT) method. The reaction time of the MWHT method at high temperature was only 1/12th that of the CHT method. The MWHT-ZnO nanorods exhibited better crystallinity than those produced by the CHT method. The ZnO nanorod had a wurtzite crystal structure oriented along the c-axis. The MWHT nanorods with their higher (002)/(101) ratio were more conducive and improved the orientation degree of the ZnO nanorods. Field emission scanning electron microscopy (FE-SEM) images showed that the MWHT-ZnO nanorods had smaller diameters and narrower size distributions than those produced by the CHT method. However, both methods formed well-aligned array coatings that covered the wood surfaces, and the two coatings had similar UV protecting effects and inhibited discoloration. [ABSTRACT FROM AUTHOR]

In special applications, such as hospitals and rehabilitation centers, hygienic wood surface with antimicrobial performance is recommendable. In the present study, the antimicrobial property of wood was increased by grafting with 2-(dimethylamino)ethyl methacrylate (DMAEMA). The reaction proceeds via radical polymerization, and analysis via Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and thermogravimetric analysis confirmed the successful grafting of DMAEMA to wood. The tertiary amino groups of the immobilized P(DMAEMA) were then quaternized by an alkyl halide, and the quaternary ammonium groups at the surface in high concentration proved to be antibacterial. The test against Escherichia coli by means of the optical density method revealed that the bactericidal effect of the modified surface is higher than that of wood and the monomeric precursors of grafting. [ABSTRACT FROM AUTHOR]

Abstract: In this work, wood materials with UV-resistant ability were successfully fabricated by depositing submicrometer-sized rutile TiO2 spheres on wood surface using a facile and one-pot hydrothermal method. The prepared samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and attenuated total reflectance-Fourier transformation infrared (ATR-FTIR) techniques. ATR-FTIR spectra demonstrated that chemical bonds were formed at the interfaces between rutile TiO2 and wood owing to the presence of hydroxyl groups. Accelerated aging was used to measure the UV resistance of the original wood (OW), anatase TiO2/wood (ATW) and rutile TiO2/wood (RTW). Comparison with OW and ATW samples, RTW exhibited more UV-resistant ability due to high UV light absorption capability, superior light scattering property and high recombination of the photogenerated electron and hole of the submicrometer-sized rutile TiO2 spheres on the wood surface. [Copyright &y& Elsevier]

The development of biomaterials-based adhesives is one of the main research directions for the wood-based material industry. In previous research, tannin and sucrose were used as adhesive to manufacture particleboard. However, the reaction conditions need to be optimized. In this study, sulfuric acid was added to the tannin⁻sucrose adhesive as a catalyst to improve the curing process. Thermal analysis, insoluble mass proportion, FT-IR, and solid state 13 C NMR were used to investigate the effects of sulfuric acid on the curing behavior of tannin and sucrose. Thermal analysis showed weight loss and endotherm temperature reduced from 205 and 215 to 136 and 138 °C, respectively, by adding sulfuric acid. In case of the adhesive with pH = 1.0, the insoluble mass proportion achieved 81% at 160 °C, which was higher than the reference at 220 °C. FT-IR analysis of the uncured adhesives showed that adding sulfuric acid leads to hydrolysis of sucrose; then, glucose and fructose converted to 5-hydroxymehthylfurfural (HMF) and levulinic acid. Dimethylene ether bridges were observed by FT-IR analysis of the cured adhesives. The results of solid state 13 C NMR spectrum indicated that 5-HMF participated in the curing process and formed methylene bridges with the C8 position of the resorcinol A-rings of tannin, whereas dimethylene ether bridges were detected as a major chemical chain of the polymer. Lab particleboards were produced using 20 wt % resin content at 180 °C and 10 min press time; the tannin⁻sucrose adhesive modified with sulfuric acid to pH = 1.0 exhibited better performance than the unmodified tannin⁻sucrose adhesive; the properties of the boards fulfilled the requirement of Japanese Industrial Standard (JIS) A5908 type 15.