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25 April 2021, Volume 41 Issue 2 Previous Issue    Next Issue

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Preparation and CO2 Adsorption Performance of Larch-based N-doped Carbon Foam Yuhang ZHANG, Hao YING, Wei LI, Chunhui MA, Sha LUO, Shouxin LIU 2021, 41 (2):  1-9.  doi: 10.3969/j.issn.0253-2417.2021.02.001 Abstract ( 315 )   HTML ( 27624 )   PDF (2703KB) ( 551 )   Save Larch-based N-doped carbon foam was prepared with larch sawdust as carbon source and urea as nitrogen source via phenol liquefaction-physical foaming-activation method. Morphology, surface chemical properties and pore structure of the prepared carbon foams were analyzed by SEM, XRD, XPS, TG and N2 adsorption-desorption isotherm. CO2 adsorption capacity and CO2/N2 adsorption selectivity of the materials were tested as well. Effects of nitrogen doping and activation temperature on CO2 adsorption performance were investigated. The results showed that carbon foam had the crystal structure of disordered stacking of graphene layers, and its disorder increased with the rise of activation temperature. Nitrogen doping reduces the size of cell and thermal stability. Nitrogen-doped carbon foam exhibited typical microporous structure with the maximum micropore content of 95.83%. The microporous pore size of nitrogen-doped carbon foams(NCF-4-900, NCF-6-900 and NCF-8-900) which were prepared under the conditions of activation temperature of 900 ℃ and urea doping amounts of 4, 6 and 8 g were mainly concentrated at 0.50, 0.81 and 1.26 nm, and the mesoporous pore size was concentrated in about 3.85 nm.The materials contained 3 types of nitrogen and they were mainly pyridine nitrogen(N-6) and pyrrole nitrogen(N-5) when the activation temperatures were 700 and 800 ℃. With the activation temperature reaching 900 ℃, some N-5 and N-6 were transformed into quaternary nitrogen(N-Q) with better thermal stability, and pyrrolic N was dominant. CO2 adsorption capacity increased with the rise of activation temperature. NCF-8-900 had the highest adsorption capacity(up to 3.19 mmol/g at 25 ℃ and 100 kPa) and excellent CO2/N2 adsorption selectivity of 118.63. Figures and Tables | References | Related Articles | Metrics

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Preparation of Nitrogen-doped Activated Carbon from Alkali/Urea Dissolution System and Its Electrochemical Properties Xuan YANG, Xinyu ZHENG, Jianhua LYU, Hao YING, Biao HUANG, Guanfeng LIN 2021, 41 (2):  10-16.  doi: 10.3969/j.issn.0253-2417.2021.02.002 Abstract ( 459 )   HTML ( 2884045 )   PDF (734KB) ( 660 )   Save Nitrogen-doped activated carbon was fabricated by one-step pyrolysis with Chinese fir sawdust as raw material, melamine solid waste(oxhydryl and amino triazine, OAT) as nitrogen-rich source, alkali/urea system as solvent. The effects of activation temperatures and melamine solid waste dosage on adsorption performance and electrochemistry performance of activated carbon were investigated. X-ray photoelectron spectroscopy(XPS) and specific surface area analyzer were used to study the surface structure and pore structure of the material. Cyclicvoltammetry(CV) curves, galvanostatical charge/discharge(GCD) and electrochemical impedance spectroscopy(EIS) were used to test the electrochemical performance of samples. The results showed that with the increase of melamine solid waste content, the yield and adsorption performance of activated carbon samples increased first and then decreased; the addition of melamine solid waste was beneficial to increase the yield, nitrogen content, adsorption performance and electrochemical performance of nitrogen-doped activated carbon. The specific surface area and pore structure of carbon materials affected the electrochemical performance of activated carbon samples. When the activation temperature was 900 ℃ and the melamine solid waste content was 15%, the yield of nitrogen-doped activated carbon was 34.2%, the iodine adsorption value was 1 116 mg/g, and the methylene blue adsorption value was 165 mg/g, specific surface area was 1 324 m2/g, nitrogen content was 3.5%. In the 6 mol/L KOH electrolyte, the specific capacitance could reach 193 F/g when the current density was 1 A/g. Figures and Tables | References | Related Articles | Metrics

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Forming Properties of Boxwood/Thermoplastic Polyurethane Fabricated by Selective Laser Sintering Hui ZHANG, Dakun LIU, Yanling GUO, Jian LI 2021, 41 (2):  17-23.  doi: 10.3969/j.issn.0253-2417.2021.02.003 Abstract ( 306 )   HTML ( 1455 )   PDF (6021KB) ( 572 )   Save A new type of wood-plastic mixtures that were used for selective laser sintering(SLS) was proposed with the advantages of low cost and good flexibility. Boxwood/thermoplastic polyurenthane(B/TPU) mixtures containing with the boxwood powder mass fraction of 2%, 5%, 10%, and 15% were prepared by mechanical mixing method, respectively. The thermal properties, mechanical properties, dimensional accuracy and microstructures of the mixtures and laser-sintered parts were tested and characterized. The effects of material ratio and process parameter on formability of laser sintering were investigated. Fractional factorial design method was applied to study the effects of process parameters on the forming properties of the laser-sintered parts. The results showed that laser-sintered boxwood/thermoplastic part with 10% boxwood powder had the best mechanical property when the preheating temperature was 48 ℃, laser power was 14 W, scan speed was 1 600 mm/s, scan spacing was 0.1 mm and layer thickness was 0.1 mm. The properties were summarized as that the tensile strength reached 4.86 MPa, the flexural strength was 9.19 MPa and the elongation at break reached 24.22%. Figures and Tables | References | Related Articles | Metrics

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Preparation of Lignin-based Ion-imprinted Polymer and Its Adsorption Properties on Cr(VI) Jinyu LIU, Ruixia LIU, Pingping DENG, Dexiang LIU, Meng GUO, Zhiping WU 2021, 41 (2):  24-32.  doi: 10.3969/j.issn.0253-2417.2021.02.004 Abstract ( 305 )   HTML ( 1321 )   PDF (3172KB) ( 537 )   Save Lignin-based ion-imprinted polymer(L-ⅡP) was prepared via graft copolymerization of sodium lignosulfonate(SL) and acrylamide(AM) with using Cr(VI) as template ion, acrylamide as functional monomer, N, N-methylene-bis-acrylamide as crosslinker and ammonium persulfate as initiator. Then the L-ⅡP's structure and adsorption performance on Cr(VI) were studied. The preparation conditions of L-ⅡP were optimized by single factor experiment and orthogonal experiment. The structure of L-ⅡP was characterized by FT-IR, SEM-EDS and pore size analysis. The adsorption experimental data were fitted by quasi-first-order kinetic equation, quasi-second-order kinetic equation, Langmuir and Freundlich isothermal adsorption equation, and the reuse of L-ⅡP was discussed. FT-IR analysis showed that the grafting copolymerization of sodium lignosulfonate and AM was successful. SEM images showed that L-ⅡP had more porous structure than lignin non-ionic imprinted polymer(L-NIP). L-ⅡP was a kind of mesoporous material with pore size of 3-5 nm and 10-20 nm. When the mass of template ion, functional monomer, sodium lignosulfonate and crosslinker were 10 mg, 0.2 g, 100 mg and 0.6 g, respectively, and the reaction was performed at 60 ℃ for 24 h, the obtained L-ⅡP exhibited the best adsorption performance of Cr(VI). The optimum adsorption conditions at room temperature were pH value of 2 and initial concentration of Cr(VI) of 800 mg/L.The adsorption of Cr(VI) was described well with the pseudo-second-order model with R2 of 0.980 1, when L-ⅡP was used as absorbent. And the adsorption isotherm was consistent with the Langmuir model with qmof 24.94 mg/g and R2 of 0.992. The results indicated that the adsorption of Cr(VI) by L-ⅡP was a monolayer adsorption dominated by chemical adsorption. The selectivity coefficients of L-ⅡP for Cr(VI) of Cu(Ⅱ) and Cr(Ⅲ) were 5.925 and 7 respectively, indicating of its excellent selective adsorption properties. L-ⅡP had good reusability, after 5 times of adsorption/desorption, the adsorption capacity could still retain more than 80% of the maximum adsorption capacity. Figures and Tables | References | Related Articles | Metrics

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Effect of Temperature on Curing Performance of Lignin-based Phenolic Resin Fibers Xin LI, Yu REN, Jianxiang LIU, Zhengjun SHI, Zhifeng ZHENG, Can LIU 2021, 41 (2):  33-38.  doi: 10.3969/j.issn.0253-2417.2021.02.005 Abstract ( 416 )   HTML ( 2621695 )   PDF (4688KB) ( 501 )   Save In order to study the influence of temperature factors on the properties of lignin phenolic resin fiber, different heating rates and curing reaction temperatures were set under the curing bath condition with the hydrochloric acid/formaldehyde mass ratio of 1:1. The properties of the cured materials were characterized by FT-IR, TG, DSC, and mechanical property test. The effects of different temperatures on the mechanical properties, thermal properties and surface morphology of the fibers were investigated, and the curing behavior of lignin phenolic fibers was studied. The results showed that the internal materials continued to cross-link and the diameter of the cured fibers was thicker than that of the raw fibers after curing. The degree of curing reaction and the thermal stability increased with the increase of heating rate. Too fast heating rate led to the decrease of mechanical properties. The higher the curing temperature was, the smoother the surface of lignin phenolic fiber was. The mechanical properties of the fibers decreased with the increase of curing temperature. The most suitable curing temperature factors were the curing heating rate of 20 ℃/h and curing temperature of 170 ℃. Under these conditions, the tensile strength of the cured fiber was 178.24 MPa, and the elongation at break was 1.49%. Figures and Tables | References | Related Articles | Metrics

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Synthesis of Methyl Levulinate by Glucose Alcoholysis Catalyzed by Mixed Acid in Alcohol/Water System Yuan WU, Zihua WANG, Chun CHANG, Pan LI, Guizhuan XU 2021, 41 (2):  39-46.  doi: 10.3969/j.issn.0253-2417.2021.02.006 Abstract ( 299 )   HTML ( 11 )   PDF (778KB) ( 464 )   Save Methyl levulinate(ML) was prepared by the alcoholysis of glucose in a methanol/water system over mixed acid catalysts comprising extremely low acid and metal sulfates. Al2(SO4)3with ultralow sulfuric acid showed the highest catalytic performance among the studied metal sulfates(Al2(SO4)3, CuSO4, Fe2(SO4)3, Ti(SO4)2, SnSO4, ZnSO4, NiSO4, and Cr2(SO4)3). Moreover, the effects of initial mass concentration of glucose(10-40 g/L), Al2(SO4)3mass in mixed acid catalyst(0.12-0.48 g), reaction temperature(160-200 ℃), and reaction time(2-6 h) on product formation were investigated. The highest yield (46.68%) of ML was obtained in methyl/water(50/50) solvent system with a raw material mass concentration of 20 g/L, 0.02 mL H2SO4(0.01 mol/L), and 0.24 g Al2(SO4)3at 170 ℃ after 4 h; under these conditions, the yield of levulinic acid(LA) was 24.20%. During the alcoholysis process, glucose was first converted to methyl glucoside(MLG), then methoxymethylfurfural(MMF), and ultimately to ML. Al2(SO4)3could be reused at least five times with a slight decrease in catalytic activity(45.92% yield of ML and 20.58% yield of LA). Figures and Tables | References | Related Articles | Metrics

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Preparation, Characterization and Adsorption Properties of Kapok-based Carbon Aerogels Haoqiang HOU, Wenye SUN, Shuangbin LI, Xiangsen MIAO, Shouxin LIU 2021, 41 (2):  47-54.  doi: 10.3969/j.issn.0253-2417.2021.02.007 Abstract ( 336 )   HTML ( 303 )   PDF (5366KB) ( 516 )   Save A kapok fiber carbon aerogel(KFCA) with hollow tubular structure was synthesized through the homogenous treatment, ambient pressure drying and carbonization. The surface morphology, pore structure, crystal structure and chemical composition of KFCA were characterized by scanning electron microscopy(SEM), N2 adsorption/desorption isotherms, X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared(FT-IR) spectroscopy, X-ray photoelectron spectroscopy(XPS) and water contact angle(WCA). The adsorption properties of KFCA were studied with the commonly used organic reagents and oils as adsorbate. The results indicated that KFCA had an unique hollow tubular structure with low density, hydrophobic surface, large specific surface area and developed pores. The water contact angle of KFCA-800(which was carbonized at 800 ℃) was 134.0°, specific surface area was up to 170.22 m2/g, the average pore diameter was 4.022 nm and the pore volume was 0.22 cm3/g. KFCA-800 was composed of C, H and O. C=O and C=C functional groups were detected on the surface of KFCA-800. Carbonization temperature had a certain effect on the adsorption performance of KFCA, among which KFCA-800 had the best adsorption performance. Its adsorption capacities of pump oil, soybean oil, N, N-dimethylformamide(DMF), ethanol, acetone, n-hexane, benzene and xylene were reach up to 52.3, 34.15, 75.21, 72.26, 54.16, 52.79, 62.06 and 38.95 g/g. In addition, KFCA could be regenerated by the methods of direct drying and extraction-drying. The adsorption capacities of KFCA-800 for ethanol and soybean oil were 69.54 g/g (more than 90% of the initial adsorption capacity) and 26.16 g/g (about 75% of the initial adsorption capacity) respectively after five adsorption-regeneration cycles. Figures and Tables | References | Related Articles | Metrics

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Characteristics of UV Curing Reaction of Allyl Cardanol Monomers Jian CHEN, Guomin WU, Shuping HUO, Zhenwu KONG 2021, 41 (2):  55-64.  doi: 10.3969/j.issn.0253-2417.2021.02.008 Abstract ( 403 )   HTML ( 7 )   PDF (1065KB) ( 530 )   Save The hydrogenated cardanol(HC) was prepared from cardanol, and then reacted with allyl glycidyl ether(AGE) to synthesize allyl ether type hydrogenated cardanol(AGE-HC). The AGE-HC reacted with methacrylic anhydride(MAA) to form allyl hydrogenated cardanol with ether bond and ester bond(MAA-AGE-HC).The characteristics of UV curing reaction of allyl cardanol monomers were studied by Fourier transform infrared spectroscopy(FT-IR) and gel permeation chromatography(GPC), with allyl ether type cardanol(AGE-C) and allyl cardanol with ether bond and ester bond(MAA-AGE-C) as contrast.The results showed that the optimal UV curing reaction conditions of allyl cardanol monomers were as follows: electrodeless lamp (iron lamp, main wavelength 365 nm) as UV source, power 1 500 W, irradiation distance 40 mm, irradiation time 60 s, 2-hydroxy-2-methyl-1-phenyl-1-acetone(1173) as initiator with the dosage of 3% of the monomer by weight. The UV curing activities of allyl cardanols were MAA-AGE-C > MAA-AGE-HC > AGE-C > AGE-HC≈cardanol. Cardanol could be cured by UV light under the condition of oxygen or photoinitiator. The curing reaction rate could be accelerated by the combination of UV and high temperature. Furthermore, the allyl ester, allyl ether and allyl alkyl were gradually cured according to the activity of functional groupsby the photoinitiated radical polymerization and thermal initiated oxygen radical polymerization. Figures and Tables | References | Related Articles | Metrics

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Investigation of RuPMoV Polyoxometalates in Preparation of γ-Valerolactone Xueting SHAO, Zhong SUN, Junyou SHI, Xixin DUAN 2021, 41 (2):  65-72.  doi: 10.3969/j.issn.0253-2417.2021.02.009 Abstract ( 367 )   HTML ( 32 )   PDF (1865KB) ( 398 )   Save A series of polyoxometalates(HPMoV) catalysts, H4PMo11VO40(V1), H5PMo10V2O40(V2) and H6PMo9V3O40(V3), with different oxidizability were synthesized. Then Ru3+ was combined with HPMoV as Lewis acid cites. As a result, RuPMoV catalysts including Ru4/3PMo11VO40(4-V1), Ru5/3PMo10V2O40(5-V2) and Ru2PMo9V3O40(6-V3) were prepared, which had both acidity and strong oxidizability. XRD, FT-IR, SEM, XPS and NH3-TPD were used to characterize the structure of the catalysts. The catalytic performance, reaction factors and kinetics were investigated during the reaction of converting levulinic acid(LA) into γ-valerolactone(GVL) in formic acid/water(FA/H2O) system, where FA was performed as hydrogen source. The results indicated that Ru3+ was introduced into the frame of polyoxometalates and the replacement of H+ in HPMoV by Ru3+, which did not change the structure of polyacid anions. The RuPMoV catalysts had the strong acidity and oxidizability. 5-V2 had the highest catalytic performance; at the condition of 0.1 g 5-V2, 6 mmol FA, 2.5 mmol LA, 5 mL H2O, 160 ℃ and 8 h, the LA conversion was 98.1% and the GVL yield and selectivity were 97.1% and 99.0%, respectively. The yield of GVL could be up to 87.5% when the 5-V2 catalyst was reused for 5 times.The reaction kinetics exhibited a first-order reaction with the activation energy of 49.59 kJ/mol and the pre-exponential factor of 2.89×105. Figures and Tables | References | Related Articles | Metrics

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Synthesis and Light-controlled Activity of Ginkgo biloba Leaves Polyprenols Metal Complex Changwei ZHANG, Ran TAO, Zhiwen QI, Hong SHEN, Xingying XUE, Chengzhang WANG 2021, 41 (2):  73-78.  doi: 10.3969/j.issn.0253-2417.2021.02.010 Abstract ( 297 )   HTML ( 79 )   PDF (790KB) ( 398 )   Save Ginkgo biloba leaves polyprenols(GBP) was used as raw material, and its terminal hydroxyl group was replaced with cyano group by chemical modification method. On this basis, cyano-GBP and ruthenium polypyridine complex were utilized as raw materials, the GBP-ruthenium polypyridine metal complex was synthesized and characterized by complex reaction. The lipid-water partition coefficient, photo-induced ligand dissociation ability and light-controlled antitumor activity of the complex were investigated. NMR results showed that the cyano-GBP and GBP-ruthenium polypyridine metal complex were successfully synthesized. The synthesized complex has good lipid-water partition coefficient(1.35), which was conducive to its penetration of cell membranes. In addition, cyano-GBP ligand of the synthesized complex gradually dissociated under light and exhibited better antitumor activity with the half inhibitory concentration(IC50) against A549 tumor cell of 29.3 μmol/L than GBP(IC50=45.8 μmol/L). Moreover, The light-controlled antitumor activity of the complex may be related to its DNA binding ability. Figures and Tables | References | Related Articles | Metrics

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Preparation and Analysis of Biomass-based N-doped Carbon Dots with Green Fluorescence Yifan LIU, Yu JIANG, Youqi HAN, Shujun LI, Guiquan JIANG, Shiyan HAN 2021, 41 (2):  79-85.  doi: 10.3969/j.issn.0253-2417.2021.02.011 Abstract ( 373 )   HTML ( 18 )   PDF (5585KB) ( 516 )   Save The extract solution was obtained by ultrasonic crushing with using larch bark as raw material and 40% ethanol aqueous solution as solvent, and ethylenediamine was then added to prepare N-doped carbon dots(NCDs) by hydrothermal synthesis method. FT-IR, XPS, TEM, XRD and UV were applied to characterize and analyze the structure of NCDs. The results showed that the prepared NCDs mainly contained three elements of C, N and O, and the surface bear benzene ring, amino, hydroxyl and carbonyl groups. The NCDs were spherical particles with an average particle size of 4.8 nm, and had (002) lattice plane of graphitized carbon core. The existences of ultraviolet absorption caused by π-π* and n-π* electron transitions was in the region of ≤300 nm and 300-600 nm. These results confirmed that NCDs were mainly composed of graphitized carbon core and surface functional groups. In addition, fluorescence analysis showed that NCDs had excitation dependence and stability against photobleaching, and the fluorescence intensity decreased with increasing temperature. The analysis of the effect of different metal ions on the fluorescence intensity of NCDs showed that Fe3+ had selective fluorescence static quenching effect on NCDs with the limit of detection(LOD) of 9.07 μmol/L. Additionally, the yellow-green phosphor NCDs/SiO2 was also prepared by the composite method and was used as the color conversion layer. The white light-emitting diodes(WLEDs) with CIE color coordinates of (0.318 2, 0.303 0), correlation color temperature of 6 381 K and color rendering index of 84.1, were obtained by using blue emission(450 nm) semiconductor chip encapsulation. Figures and Tables | References | Related Articles | Metrics

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Preparation and Electrochemical Property of Degraded Wood-based Porous Carbon Weiting ZHONG, Zunqiang HAN, Chang LIU, Kun WANG 2021, 41 (2):  86-92.  doi: 10.3969/j.issn.0253-2417.2021.02.012 Abstract ( 318 )   HTML ( 56 )   PDF (4531KB) ( 504 )   Save Three dimensional porous carbon materials(PC-1, PC-2 and PC-3) were prepared by hydrothermal carbonization with high activation temperature at different mass ratios of carbon to KOH(1:1, 1:2 and 1:3) using mushroom culture medium waste degraded wood as carbon source and KOH as activator. The samples were characterized by SEM, TEM, N2 adsorption-desorption, XPS, XRD and Raman spectroscopy, and the results showed that the material had larger specific surface area and more micropores, which was conducive to ion transport and charge accumulation. The results of galvanostatic charge discharge(GCD), cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS) tests showed that when the mass ratio of carbon to KOH was 1:1, the specific capacitance of PC-1 could reach 221 F/g at the current density of 1 A/g, with rapid ion response, excellent capacitance performance, good cycle stability(after charge and discharge for 5 000 times, the coulomb efficiency was always over 99.5%) and excellent electrochemical performance. Figures and Tables | References | Related Articles | Metrics

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Wood and Fiber Properties, and Pulping Performance of Four Taxodium Hybrid 'Zhongshanshan' Shan XU, Shanqi WAN, Shufang WU, Chaoguang YU, Yunlong YIN 2021, 41 (2):  93-102.  doi: 10.3969/j.issn.0253-2417.2021.02.013 Abstract ( 375 )   HTML ( 9 )   PDF (12251KB) ( 332 )   Save The wood densities, crystallinities, chemical compositions, macrostructure, fiber morphological characteristics and pulping performance of four 11-year-old Taxodium 'Zhongshanshan' (T. 'Zhongshanshan'405, T. 'Zhongshanshan'406, T. 'Zhongshanshan'407, T. 'Zhongshanshan'502) and their parents, Taxodium distichum and Taxodium mucronatum were studied. The results showed that the basic densities of four T. 'Zhongshanshan' woods arranged from 0.24 to 0.33 g/cm3, which were slightly lower than those of T. mucronatum (0.33 g/cm3) and T. distichum (0.34 g/cm3). The arithmetic average and weighted average length of T. 'Zhongshanshan' wood fiber were 1.09-1.31 mm and 1.52-1.73 mm, respectively, which were between that of T. mucronatum and T. distichum. The ratios of length to diameter of wood fiber of T. 'Zhongshanshan' were close to that of T. mucronatum, which were lower than that of T. distichum. The total polysaccharide mass fraction of T. 'Zhongshanshan' wood was similar to that of their parents, which accounted for about 60% of the dry weigh of wood. Also, lignin mass fraction was about 31.0%-33.2% of the dry weight of wood, which were slightly lower than that of parents. The ash mass fraction of T. 'Zhongshanshan' wood was higher than that of parents and all were less than 1%. Typical coniferous tracheids could be seen on the cross section of T. 'Zhongshanshan' wood. The parenchyma cells were scattered and a large number of traumatic resin canals could be seen at the junction of early and late wood. The tangential section presented an uniserial wood ray, consisting of 2-22 cells. Additionally, the pulping performance of T. 'Zhongshanshan' 406 and T. 'Zhongshanshan' 407 were investigated. The kappa number of the pulp was around 38 when the cooking yield achieved 45%-46%. The investigation on oxygen delignification of kraft pulp found that the delignification rate was about 64%, good and the delignification selectivity was good. The brightness of the pulps achieved 75%-78%(ISO) after DED bleaching. Figures and Tables | References | Related Articles | Metrics

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Synthesis, Structurally Characterization and Alga Inhibiting Activity of ω-Isothiocyanomethyl Longifolene Mengzhu WANG, Hongyun LAN, Daozhan HUANG, Maomao ZHU, Hong ZOU 2021, 41 (2):  103-109.  doi: 10.3969/j.issn.0253-2417.2021.02.014 Abstract ( 403 )   HTML ( 2560 )   PDF (716KB) ( 371 )   Save ω-Isothiocyanomethyl longifolene(Ib) with low irritating odor was selectively synthesized by substitution reaction of lead thiocyanate and ω-chloromethyl longifolene(Ia) under reflux heating with hexane as solvent. The final product was characterized through HRMS, FT-IR, UV, 1H NMR and 13C NMR. The molecular formula of C17H25NS was determined by HRMS, and the presence of N=C=S structure and long-leaf alkene structure was confirmed by FT-IR, UV spectroscopy and 1H NMR and 13C NMR spectroscopy, respectively. Compound Ib could be regarded as an allyl isothiocyanate compound, containing longifolene and methyl isothiocyanate molecule structure moiety. The algae inhibitory activity of compound Ib was evaluated by 96-well plate two-fold dilution assay. It was obtained that compound Ib was able to inhibit the growth of Scenedesmus obliquus and Skeletonema sp. with the MIC of about 62.5 and 31.2 mg/L, respectively, and the algae inhibitory activity was significantly better than that of compound Ia, longleafene and methyl isothiocyanate. Figures and Tables | References | Related Articles | Metrics

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A Review of Torrefaction Pretreatment for Preparation Biomass Clean Briquette Fuels Tingzhou LEI, Xiaofei XIN, Zaifeng LI, Jinping LI, Liya ZHANG 2021, 41 (2):  110-118.  doi: 10.3969/j.issn.0253-2417.2021.02.015 Abstract ( 467 )   HTML ( 17293 )   PDF (658KB) ( 655 )   Save As an important part of renewable energy, biomass resources have a wide range of sources. However, large-scale application is limited due to the properties of biomass, such as dispersion, low bulk density, low calorific value, and high hygroscopicity. Solid briquette fuel is one of the important ways to promote the large-scale application of biomass, which can replace coal and other fossil fuels. As one of the pretreatment methods to improve the physical and chemical properties of briquette fuel, torrefaction can improve the hydrophobicity of biomass briquette fuel and optimize its physical and chemical properties, which is a research hot topic at home and abroad. In this paper, the factors of torrefaction pretreatment and characteristics of torrefaction products were summarized, the factors and the lignin bonding mechanism of the pelletization process were analyzed, the influence of torrefaction pretreatment on the preparation of clean solid fuel was described, and the application of torrefaction and upgrading solid fuel process was prospected. This paper provides reference for promoting the development and application of biomass briquette fuel in China. Figures and Tables | References | Related Articles | Metrics

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Review of Solvent System for Electrospinning of Cellulose/Chitosan Nanofibers Kaimeng XU, Zhihui WANG, Zhengjun SHI, Jiaxi WU, Yulu ZHANG, Guanben DU 2021, 41 (2):  119-129.  doi: 10.3969/j.issn.0253-2417.2021.02.016 Abstract ( 546 )   HTML ( 9437208 )   PDF (5660KB) ( 847 )   Save Cellulose and chitosan are the two most abundant natural biomass polymers on the earth. The novel, green and functional composite nanofibers derived from cellulose and chitosan were expected to be obtained by electrospinning, which can further expand their applications. The selection and development of the optimum solvent system is a crucial prerequisite and guarantee for the preparation of high-quality nanofibers by electrospinning. The characteristics, dissolution effects, mechanisms and spinning performance of the main solvent systems(including organic solvents, aqueous solvents and ionic liquid solvents) for electrospun cellulose, chitosan single and composite nanofibers were reviewed, which could provide a theoretical reference for the high value-added nano-utilization of cellulose and chitosan as well as the development of functional biocomposite nanofibers. Figures and Tables | References | Related Articles | Metrics

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Research Progress of Hydrodeoxygenation Catalysts for Bio-oil Model Compounds Le TONG, Le ZHANG, Hui PAN, Huimin ZHU, Junfeng FENG 2021, 41 (2):  130-140.  doi: 10.3969/j.issn.0253-2417.2021.02.017 Abstract ( 479 )   HTML ( 72709 )   PDF (735KB) ( 621 )   Save Hydrodeoxygenation(HDO) process of phenolic compound is an important process for upgrading and refining bio-oil to high value-added chemicals and high-quality liquid fuel, in which the catalyst plays a vital role. Research on the catalytic process of hydrodeoxygenation of bio-oil model compound phenols has important reference significance for bio-oil upgrading and refining. Phenolic compound hydrodeoxygenation catalysts mainly include precious metal catalysts, non-precious metal catalysts and bimetallic catalysts. This paper summarized the advantages and disadvantages of various catalysts, and briefly described the mechanism of various catalysts in the process of phenol hydrodeoxygenation. And the catalyst was evaluated for substrate conversion, product selectivity, and catalyst stability. Figures and Tables | References | Related Articles | Metrics