作者机构：
[李中昊; 张晓萌; 周川玲; Lü J.; 李贤军] College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China;Zhejiang Academy of Forestry, Hangzhou, 310023, China;[徐康] College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China, Zhejiang Academy of Forestry, Hangzhou, 310023, China
通讯机构：
[Xu, K.] C;College of Material Science and Engineering, China
期刊：
Industrial Crops and Products,2020年145:112100 ISSN：0926-6690
通讯作者：
Li, Xianjun
作者机构：
[Yang, Xi; Li, Xianjun; Cao, Min] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;[Liu, Xinge; Kong, Lingyu] Int Ctr Bamboo & Rattan, Dept Biomat, Key Lab Bamboo & Rattan Sci & Technol, Beijing 100102, Peoples R China.
通讯机构：
[Li, Xianjun] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.
关键词：
Capacitive behavior;Porous carbon nanosheets;Rattan-based carbon aerogel;Supercapacitors;Wide-range of miro-mesopores
摘要：
Porous carbon materials with well distributed micro-mesopores from biomass resources for supercapacitors application have attracted considerable attention because of both the environmental issues caused by fossil and its great depletion. A novel porous nanposheets-based carbon aerogel was synthesized by a combined process of complete delignification, carbonization and chemical activation of a sustainable source of rattan. The biomass supramolecular structure changes and carbon formation were technically monitored by spectroscopy and thermochemistry. Based on the metabolic channels and preparation resulted pores, the nanposheets-based carbon aerogel shows a large number of and a wide range of miro-mesopores together with a large specific surface area (2436 m2 g−1). When used as an active material for supercapacitor, such rattan derived hierarchical porous carbon aerogel reveals an inspiring specific capacitance of 221 F g−1 at 0.5 A g−1 and an excellent rate capability of owing 80% capacitance retention at a current density of 20 A g−1. These promising characteristics provide a high-value solution for developing renewable rattan source into an active material for high-performance supercapacitors.
Porous carbon materials with well distributed micro-mesopores from biomass resources for supercapacitors application have attracted considerable attention because of both the environmental issues caused by fossil and its great depletion. A novel porous nanposheets-based carbon aerogel was synthesized by a combined process of complete delignification, carbonization and chemical activation of a sustainable source of rattan. The biomass supramolecular structure changes and carbon formation were technically monitored by spectroscopy and thermochemistry. Based on the metabolic channels and preparation resulted pores, the nanposheets-based carbon aerogel shows a large number of and a wide range of miro-mesopores together with a large specific surface area (2436 m2 g−1). When used as an active material for supercapacitor, such rattan derived hierarchical porous carbon aerogel reveals an inspiring specific capacitance of 221 F g−1 at 0.5 A g−1 and an excellent rate capability of owing 80% capacitance retention at a current density of 20 A g−1. These promising characteristics provide a high-value solution for developing renewable rattan source into an active material for high-performance supercapacitors.
摘要：
The Box-Behnken Design (BBD) and Response Surface Methodology (RSM) was extended to study the impregnation process on optimized furfurylated bamboo. The effect of furfuryl alcohol (FA) concentration, impregnation pressure and impregnation time on weight percentage gain (WPG) and chromatic aberration (CA) of bamboo were investigated. The regression model for impregnation process was significant (p < 0.01), and the FA concentration had a significant effect on WPG, meanwhile FA concentration and impregnation time had significant effects on CA. The experimental results indicated that the optimal conditions were 18.89%, 0.41 MPa and 44.89 min for FA concentration, impregnation pressure and impregnation time, respectively. Under this condition, the WPG and CA were found to be 16.52% and 57.13 NBS respectively, which were in agreement with the predicted value (15.81% and 56.71 NBS). At optimized conditions of impregnation process, the analysis of Fourier transform infrared (FTIR) spectrometry revealed that FA could polymerized inside the bamboo or underwent a substitution reaction with the hydroxyl group within the cell wall.
作者：
He Xia;Wang Yong;Li Yunyan;Wei Yanqiang;Quan Peng;...
期刊：
Science of Advanced Materials,2020年12(8):1236-1241 ISSN：1947-2935
通讯作者：
Li Xianjun
作者机构：
[Li Yunyan; He Xia; Li Xianjun; Quan Peng; Wei Yanqiang; Wang Yong] Cent South Univ Forestry & Technol, Mat Sci & Engn Coll, Changsha 410004, Hunan, Peoples R China.;[Wang Yong] Hunan Acad Forestry, Inst Forest Prod & Ind, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Li Xianjun] C;Cent South Univ Forestry & Technol, Mat Sci & Engn Coll, Changsha 410004, Hunan, Peoples R China.
关键词：
Eucalyptus urophylla;Dielectric Properties;Moisture Content;Grain Direction;Temperature;Radio Frequency
摘要：
<jats:p>Dielectric properties of <jats:italic>Eucalyptus urophylla</jats:italic> wood were measured by using a network analyzer over an ultrawide frequency range between 0.2 GHz and 20 GHz. The effects of moisture content (MC), temperature and frequency on the dielectric permittivity and the dielectric loss factor
of <jats:italic>Eucalyptus urophylla</jats:italic> were investigated along different grain directions. The results showed that the dielectric permittivity along with the dielectric loss factor increased significantly with the elevation in MC. At the frequency of 2380 MHz with the MC increasing from 0% to 100%,
the dielectric permittivity along different grain directions (including longitudinal, radial and tangential directions) increased by 180%, 110% and 112%, respectively, while the loss factor along these three directions increased by 1642%, 3703% and 5058%, respectively. In addition, the increase
in dielectric properties of <jats:italic>Eucalyptus urophylla</jats:italic> wood was determined with the temperature elevating. When the temperature elevated from 20 °C to 140 °C, the dielectric permittivity at 2380 MHz along the longitudinal, radial and tangential directions, increased by 19%, 14% and
15%, respectively, while the loss factor increased by 133% at most. As the radio frequency increased, the dielectric permittivity of wood decreased. Regression equations satisfactorily described the dielectric properties of wood along different grain directions with different moisture contents.</jats:p>
期刊：
Chemical Communications,2020年56(3):340-343 ISSN：1359-7345
通讯作者：
Wan, Caichao;Wu, Yiqiang
作者机构：
[Wei, Song; Wu, Yiqiang; Wan, CC; Wan, Caichao; Li, Xianjun] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Jiao, Yue; Li, Jian] Northeast Forestry Univ, Mat Sci & Engn Coll, Harbin 150040, Heilongjiang, Peoples R China.
通讯机构：
[Wan, CC; Wu, YQ] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
摘要：
A novel anode material with a delicate composite structure, which is assembled by growing 3D MoSe2 nanoflowers onto the hierarchically anisotropic carbon architecture, is designed for the first time. The structural superiority and synergistic effects from EDLC and pseudocapacitance endow the free-standing anode with an ultra-high areal capacitance of 1043 mF cm-2 at 1 mA cm-2 and high cycling stability. Moreover, an asymmetric supercapacitor device consisting of this anode and a common MnO2-based cathode yields a quite large energy density of 147 muW h cm-2 at the power density of 2 mW cm-2, which is higher than or comparable to that of some Li-ion batteries. These results verify the huge application potential of this new anode for supercapacitors.
摘要：
To improve the hydrophobicity and thermoplastic processability of starch, lactic acid esterified starch (LA-e-starch) was prepared by in-situ solid phase esterification with corn starch as the raw material and LA as the esterifying agent. Fourier transform infrared spectroscopy confirmed that the esterification reaction was successful. The optimal esterification efficiency of LA-e-starch was obtained when the LA proportion was 20% by mass, catalyst ratio at 3%, reaction temperature 80 degrees C and reaction time 2.5 h. LA-e-starch was characterized by scanning electron microscopy (SEM), contact angle (CA) analysis, X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) as well as its water absorption rate evaluated. Results showed that in-situ solid phase esterification mainly occurred on starch granule surfaces and did not destroy the starch granularity. LA-e-starch surfaces were covered with a layer of polylactic acid resin, which caused starch granules to stick together. The initial contact angle of LA-e-starch was clearly larger than that of native starch and the water absorption rate lower than native starch in a 168 h test time, which showed that esterification effectively improved the hydrophobicity of starch. This esterification destroyed the crystalline structure of starch to some extent, resulting in a crystallinity reduction to 25.16%. In addition, the gelatinization temperature and enthalpy were lower than those of native starch. XRD and DSC analyses indicated that esterification modification increased starch thermoplasticity. Also, LA-e-starch exhibited better thermal stability than native starch, from which it was inferred that this application of esterification could improve the thermoplastic processability of starch modify the interfacial compatibility between starch and polymer resins.
摘要：
The synthesis and electrical double-layer capacitor (EDLC) application of hierarchical porous bio-carbons with micropores to macropores have attracted considerable attention due to the limited fuels and environmental issues. The dependence of EDLC performance on the microstructure, pore texture, electrical conductivity and surface functionality of porous carbon aerogels (PCAs) originating from bamboo cellulose, were investigated. The result demonstrates that the highest stability EDLC has excellent cycle life with 100% capacitance retention at 30,000th cycle, which is mainly attributed to a hierarchically porous structure of owning a large micropore volume and a small mean pore size instead of the highest specific surface area. The superior capacitance and rate capability are highly dependent on the surface area and pore volume of PCAs, which are improved by increasing both activation temperature and KOH mass. These results provide another view for developing renewable and high-stable supercapacitors based on porous carbon aerogels with a large micropore volume.
摘要：
The objective of this paper was to develop a novel cross-linking agent to improve the water resistance of soy-based adhesive. The cross-linking agent was synthesized by polypropylenglycol diglycidyl ether (PPDGDE) and triethylene tetramine (TETA), and characterized by Fourier transform infrared spectroscopy (FTIR) to investigate the reaction between PPDGDE and TETA. The adhesive samples were analyzed by FTIR and X-ray photoelectron spectrometer (XPS). Also, three-plywood panels were prepared to examine the shear strength. The water-insoluble content and thermal behavior of all adhesive samples were also investigated in detail. The results showed that the wet shear strength of the plywood bonded by the resulting adhesive increased by 161.3% to 0.81 MPa with 65% water-insoluble content compared to the unmodified soy-based adhesive, which met the requirements of type-II applications (Chinese Standard GB/T 9846.3). Through FTIR and XPS analyses, it was found that the cross-linking degree and hydrophobic groups of the resulting adhesive were both increasing. Because PPDGDE and TETA established a network structure with epoxy groups after the synthesis reaction, which afterward formed an interpenetrating network structure with soy protein molecules, and thus enhanced water resistance of the resulting adhesive. Moreover, TG analysis demonstrated that thermal stability of the modified adhesive was much better than the pristine adhesive, also verifying the formation of network structure.
