HOLZFORSCHUNG
·
2021
·Vol. 75
·期 12
·1150-1158
·
IF 2.393
Xiaoshuang Shen,Dengkang Guo,Pan Jiang,Gaiyun Li,Sheng Yang,Fuxiang Chu
Wood properties of furfurylation can be altered by reaction mechanisms of furfuryl alcohol polymer (PFA) and cell walls. Although chemical reactions between PFA and lignin have been studied, reaction mechanisms between PFA and cell wall components, including lignin, cellulose and hemicellulose are still not comprehensively understood. In order to elucidate chemical reactions regarding PFA with wood cell walls, model compounds of main cell wall components were used to investigate its reactions with PFA by 13 C NMR spectroscopy and differential scanning calorimetry (DSC). Results showed that there was no chemical bonding of PFA with either cellulose or hemicellulose. Condensations of uncrowded ring positions ( meta, ortho and para ) and side chains (α–C, β–C, β–OH, and γ–OH) of lignin with PFA did occur based on 13 C NMR spectra. Reaction enthalpy and activation energy also confirmed the condensation reactions between lignin and PFA. This study could provide design guidelines to control the chemical reactions of PFA in cell walls and lignin and, therefore, improve the properties of furfurylated wood.
研究领域:
材料科学
·
化学
·
木材科学与技术
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DOI
高影响因子
HOLZFORSCHUNG
·
2019
·Vol. 74
·期 5
·513-521
·
IF 2.579
Yijie Zhou,Yong Qian,Senyi Wu,Xiaowen Zhong,Jinhao Huang,Xueqing Qiu
Aiming to improve the poor miscibility between lignin and non-polar materials, alkali lignin (AL) was self-assembled into lignin reverse micelles (LRM) and blended with high-density polyethylene (HDPE) to fabricate composite films. The particle size of AL increased from 3.5 nm to 130 nm after forming LRM, showing a uniform spherical morphology. The water droplet contact angle increased from 54° to 89°. Optimal and rheological analysis revealed that composite films exhibited good transparency, ultraviolet (UV)-blocking performance and low viscoelasticity after adding the nano LRM. Under the optimal dosage of 5 wt% LRM, the composite film can screen 93% UV rays, and the apparent viscosities, complex viscosities, storage and loss modulus of the mixture were the lowest. Atomic force microscopy (AFM) was used to investigate the molecular interactions between lignin and HDPE. The average adhesion force between LRM and HDPE in dry air was 1.07 mN m −1 , while that between AL and HDPE was 0.77 mN m −1 . AFM experiments fundamentally demonstrated better compatibility between LRM and HDPE, which was beneficial for the improvement of UV-blocking, rheological properties, as well as their processability of LRM/HDPE films.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
HOLZFORSCHUNG
·
2018
·Vol. 73
·期 4
·393-399
·
IF 2.079
Yue Dong,Xiaodi Ji,Fenglong Li,Tat Thang Nguyen,Zhanhua Huang,Minghui Guo
A self-cleaning surface treatment has been developed, which is prepared by an eco-friendly and effective two-step method. First, graphitic carbon nitride (g-C 3 N 4 ) was deposited on the wood surface by vacuum impregnation, followed by heat treatment. The morphology, weight change, dimensional stability, crystal and micro structure, and elemental composition of the wood samples were determined by photography, weighting, swelling rate determination, X-ray diffraction (XRD) and scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDXA). Moreover, contact angle measurements and photocatalytic degradation experiments were carried out with Rhodamine B as the target. It was demonstrated that g-C 3 N 4 is successfully deposited on the wood surface, which lowers the heat treatment temperature and renders photocatalytic properties to the coating. The heat treatment at around 210°C strengthened the immobility of g-C 3 N 4 and increased the surface hydrophobicity. Moreover, the better photocatalytic ability of the surface is accompanied with self-cleaning effects.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
HOLZFORSCHUNG
·
2018
·Vol. 73
·期 5
·469-474
·
IF 2.079
Yaoge Huang,Gaiyun Li,Fuxiang Chu
Poplar wood samples (2×2×2 cm 3 ) were vacuum/pressure impregnated in alcoholic solution with 2-hydroxyethyl methacrylate (HEMA) and 3-(methacryloxy)propyltrimethoxysilane (MAPTES) in a mass ratio of 3/1 in the presence of catalytic amounts of azobisisobutyronitrile (AIBN). Because of their good solubility and permeability, the HEMA/MAPTES precursors evenly penetrate the poplar cell wall. The impregnated samples were heated at 75°C for 8 h, followed by a heating period at 103±2°C for 8 h, in the course of which an in situ polymerization occurred in the cell wall. The modified wood was characterized by Fourier transform infrared (FTIR) and Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Moreover, the dimensional stability of the modified wood was measured and found to be considerably improved.
研究领域:
材料科学
·
木材科学
✓ 已验证
产品关联
DOI
高影响因子
HOLZFORSCHUNG
·
2016
·Vol. 71
·期 2
·179-188
·
IF 1.711
Min Yu,Kai Liu,Shengquan Liu,Haiyan Chen,Liang Zhou,Yamei Liu
Auxins as phytohormons, responsible for coordination of growing processes, also contribute to the formation of tension wood (TW) in trees, but the mechanism of this process is still unclear. In this study, it has been tried to induce TW formation in erect hybrid poplar trees (in opposite to inclined or bended trees) by treatment with exogenous indole-3-acetic acid (IAA, as one of the auxins) or N-1-naphthylphthalamic acid (NPA) as an auxin transport inhibitor. The treatment with IAA resulted in TW formation and, as expected, NPA treatment did not. The gelatinous fiber formation and higher cellulose content in the cell wall were unambiguous indicators for TW formation. Real-time polymerase chain reaction (PCR) analysis revealed that genes of PIN1 , ABCB1, and AUX2 involved in polar auxin transport were highly expressed in trees treated with exogenous IAA. Moreover, expressions of cellulose biosynthesis related genes of UGP1 , UGP2 and CesA13 were strongly up-regulated. These observations indicate that the accelerated intercellular polar auxin transport caused by exogenous IAA is accounted for TW formation, i.e. the signal transduction of auxin is affected, which then facilitates cellulose biosynthesis. In contrast, the transcript abundances of PIN1 and all selected cellulose synthases ( CesAs ) were decreased after NPA treatment via inhibiting the cellular auxin efflux with negative effects on plant’s primary growth. These results are interpreted that TW formation is closely associated with the acceleration of intercellular polar auxin transport.
研究领域:
植物学
·
分子生物学
·
林学
✓ 已验证
产品关联
DOI
高影响因子
HOLZFORSCHUNG
·
2018
·Vol. 72
·期 11
·973-978
·
IF 2.079
Hui-Chao Hu,Tong Zeng,Shaokai Zhang,Lihui Chen,Liulian Huang,Yonghao Ni
A solvent-assisted and pyrogallol (PG)-protected headspace gas chromatography (HS-GC) method was developed to determine the pinene (α- and β-pinene) content in the kraft pulping black liquor (BL). Ethanol (EtOH) addition eliminated pinene’s micelles in BL by complete dissolution in the EtOH/BL medium. PG was applied to protect pinene from oxidation during the sample storage and measurement. The results showed that, with a 25% (v/v) of EtOH content and a 0.1 g of PG in 5-ml of sample solution, a rapid and stable pinene HS extraction can be obtained in 20 min at 80°C. The method has high precision with relative standard deviations within 4.2%. The sensitivity [limits of quantification (LOQ) are ~140 μg l −1 ] was high, and a good accuracy (recovery=96.0–104%) was typical for the pinene detection. The presented method is simple, rapid, accurate and is suitable for pinene quantification in biorefinery related processes and it leads to the preparation of high-value chemicals.
研究领域:
分析化学
·
制浆造纸工程
·
生物炼制
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产品关联
DOI
高影响因子
HOLZFORSCHUNG
·
2020
·Vol. 74
·期 8
·799-809
·
IF 1.826
Yu Wang,Zuwu Tang,Shengchang Lu,Min Zhang,Kai Liu,He Xiao,Liulian Huang,Lihui Chen,Hui Wu,Yonghao Ni
Wood is a natural, abundant, renewable resource, which is easily processed, has beautiful texture and good mechanical strength, and is widely used for furniture, flooring, decor and building construction. However, wood is vulnerable to moisture and microorganisms, resulting in deformation, cracks, mold and degradation, which causes aesthetic problems and/or shortens the service life of wood products. In this paper, superhydrophobic wood (wood-F) was fabricated by grafting poly(2-(perfluorooctyl)ethyl methacrylate) (PFOEMA) onto wood by atom transfer radical polymerization (ATRP). Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) with an energy-dispersive X-ray spectroscopy (EDS) showed that PFOEMA was successfully grafted onto wood. The resultant wood-F exhibited excellent water resistance with a contact angle (CA) of 156° and hysteresis of 4°. The modified wood also showed abrasion resistance, self-cleaning ability and anti-mold properties, all of which are desirable for various wood products.
研究领域:
材料科学
·
木材科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
HOLZFORSCHUNG
·
2015
·Vol. 70
·期 4
·361-367
·
IF 1.565
Xin Rao,Yongzhuang Liu,Yanchun Fu,Yixing Liu,Haipeng Yu
A transparent and protective multilayer coating composed of poly(allylamine hydrochloride) (PAH), poly(styrene sulfonic acid) sodium salt (PSS), and nano-TiO 2 films was fabricated on wood surfaces by layer-by-layer assembly method. The coating was formed through pre-immobilization of cationic PAH layer on wood substrate, followed by alternate soaking cycles in pH-controlled anionic PSS solution and TiO 2 colloidal solution. The structure and properties of the assembled coating were characterized through scanning electron microscopy (SEM), energy disperse X-ray analysis (EDXA), UV reflection and absorption, colorimetry, and contact angle (CA) measurement. Results revealed that the coverage uniformity and thickness were improved with increasing number of PSS/TiO 2 bilayers. The coating masked the cell wall ultrastructure while leaving the microscale features intact. The anatase TiO 2 in the assembled coating enhanced the UV stability of wood and resulted in a lowered photochromism. Furthermore, the photocatalytic capability of the nano-TiO 2 films in degrading dyes of rhodamine B and methylene blue was verified. The nano-TiO 2 film on the top surface of the coating embodied a superhydrophilicity, showing self-cleaning and anti-fog capabilities. Stearic acid modification altered the superhydrophilicity to hydrophobicity with CA of 140°.
研究领域:
材料科学
·
木材科学
✓ 已验证
产品关联
DOI
高影响因子
HOLZFORSCHUNG
·
2022
·Vol. 76
·期 8
·732-743
·
IF 2.493
Zhenju Bi,Li Yan,Zhangjing Chen,Yafang Lei,Guangbin Li
The improvement of wood decay resistance is more inclined to eco-friendly methods such as the application of natural products, but the low durability of some natural products as wood preservatives limits their applications. In this study, vanillin catalyzed by laccase was grafted into poplar wood to increase wood decay resistance and can remain in wood for longer period. The reaction system of vanillin, ABTS, laccase and phosphate buffer solution was impregnated into poplar wood using vacuum-pressure method, and reacted at 40 °C for 6 h. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR) were used to confirm the grafting reaction actually occurring during the process. The decay resistance, leaching resistance and mechanical strength of grafted wood were evaluated. Energy-dispersive X-ray (EDX) mapping was used to characterize the vanillin distribution. The results indicated that vanillin grafted poplar wood had good decay resistance, leaching resistance and higher strength. The mass loss of grafted poplar wood exposed to white-rot fungi [ Trametes versicolor (L. ex Fr.) Quél.] and brown-rot fungi [ Gloeophyllum trabeum (Pers.: Fr.) Murr.] decreased from original 46 and 13% to 9 and 4%, respectively, even after leaching. The modulus of rupture (MOR) and modulus of elasticity (MOE) of the grafted poplar were 11 and 26% stronger than original poplar wood. Vanillin was found in wood cell wall. It was actually esterified onto wood catalyzed by the laccase.
研究领域:
材料科学
·
化学
·
林业
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHARACTERIZATION
·
2024
·
IF 4.8
Wenya Li,Yongsheng Liu,Jingxin Li,Yejie Cao
(Ti 0.2 Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2 )B 2 -SiC ceramics with an open porosity of only 0.49 % were successfully fabricated in this work by the reactive melt infiltration (RMI) method. Air plasma flame ablation behavior of (Ti 0.2 Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2 )B 2 -SiC ceramics under 2300 °C temperature exhibited excellent resistance with mass and linear ablation rates of 3.66 mg/s and 0.88 μm/s, respectively. During ablation, the transition from continuous melting sublimation of Si and oxidation of SiC to oxidation of (Ti 0.2 Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2 )B 2 occurred. The uphill diffusion of Ti atoms transited (Ti,Zr,Hf,Nb,Ta)O x to Ti(Nb x Ta 1-x ) 2 O 7 while Zr 0.5 Hf 0.5 O 2 continuously precipitated. A multicomponent oxide layer of (Ti,Zr,Hf,Nb,Ta)O x along with (Zr,Hf) 6 Ta 2 O 17 , (Hf,Zr)(TiO 4 ) 2 , and (Zr,Hf) x (Ti,Ta) 1-x O embedded in SiO 2 melt was eventually formed on the ceramic surface. This oxide layer was spread above the high melting point Zr 0.5 Hf 0.5 O 2 , Ti(Nb x Ta 1-x ) 2 O, and low oxygen content (Ti,Zr,Hf,Nb,Ta)O x to form a stable, dense, and high viscosity protective layer.
研究领域:
材料科学
·
航空航天材料
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Xiumei Wu,Jianwei Teng,Yunping Li,Shu Yu
Hafnium (Hf)-modified silicon oxycarbide (SiOC) ceramics were prepared by preceramic polymer pyrolysis using dimethyldimethoxysilane and methyltrimethoxysilane as precursors and hafnium acetylacetonate as a modifier, followed by spark plasma sintering (SPS). The structural evolution of SiHfOC ceramics with various Hf/Si molar ratios (0–0.08) and the oxidation behavior of SPS-densified ceramic bulks in air at 1500 °C were systematically investigated. From C0Hf to C0.05Hf, the oxide layer evolved from a cracked SiO 2 -rich layer into a thinner and more continuous Hf-Si-O composite layer containing more uniformly distributed HfSiO 4 particles. After oxidation for 32 h, C0.05Hf exhibited the lowest mass loss of 0.195 mg/cm 2 and the smallest oxide-layer thickness of 8.1 μm. Nanoindentation results further indicated improved resistance of the oxide layer to local deformation. The increased formation and more uniform distribution of HfSiO 4 phase reduced cristobalite-related phase transformation strain and thermal-expansion mismatch while enhancing the barrier effect against inward oxygen transport. By contrast, excessive Hf content (Hf/Si molar ratio = 0.08) led to the rapid development of an HfSiO 4 -rich outer region, accompanied by bubble growth, rupture pits, and local spallation, which damaged the integrity of the oxide layer. These results indicate that the Hf-content-dependent phase constitution and oxide-layer architecture govern the oxidation behavior of SiHfOC ceramics at 1500 °C.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Jing Wang,Min Wang,Zhenjiang Lu,Jing Xie,Jianguo Huang,Jindou Hu,Yali Cao
The inefficient Ni/Fe ion utilization and poor electrical conductivity of nickel-iron layered double hydroxide (NiFe-LDH) restricts to its development in electrocatalytic oxygen evolution reaction/urea oxidation reaction (OER/UOR). Herein, self-supported Hf-doped NiFe-LDH nanosheet arrays were successfully prepared on nickel foam (Hf-NiFe-LDH/NF) via a one-step solvothermal approach for the first time, in which the introduced high-valent Hf 4+ altered the structure of electrons and chemical environment of the atoms and promoted the production of more active sites, thus realizing the fast kinetics of electron transfer on the layer. Meanwhile, the doped metal Hf ions increased the electric conduction and recycling stability of the catalyst. Astoundingly, the overpotential of Hf-NiFe-LDH/NF is barely 258 mV at a current density of 100 mA cm −2 , which is 61 mV lower than that of NiFe-LDH/NF, as well as outstanding stability for over 90 h during the OER. Similarly, the potential is only 1.37 V at 100 mA cm −2 during the UOR, 118 mV less was than at OER. Notably, Hf-NiFe-LDH/NF electrocatalyst exceeds the most previously reported electrocatalysts in terms of performance. This study highlights the benefits of Hf doping strategy in electrocatalytic OER/UOR and presents a promising new type of catalyst for future research.
研究领域:
材料科学
·
电化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）