Table of Content

28 April 2023, Volume 43 Issue 2 Previous Issue    Next Issue

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Research Progress in Preparation of Biomass Based 2, 5-Furan Dicarboxylic Acid from Furoic Acid Chun CHANG, Jinsheng WU, Zhiyong CHEN 2023, 43 (2):  1-11.  doi: 10.3969/j.issn.0253-2417.2023.02.001 Abstract ( 495 )   HTML ( 17 )   PDF (741KB) ( 448 )   Save As a green bio-based platform chemical, 2, 5-furan dicarboxylic acid(FDCA) was widely used in polyester, plasticizer, fire protection, medicine, etc. At present, according to the distinction of raw materials for the synthesis of FDCA, the synthetic routes of FDCA could be divided into 5-hydroxymethylfurfural(HMF) route, furoic acid route and other raw material routes. Among them, furfural acid could be prepared from the oxidation of bulk bio-based chemical furfural, and the industrial production of furfural made the preparation of FDCA from furfural acid had the potential advantages of green and economical. Based on this, this paper reviews the research status of four methods for preparing FDCA from furoic acid, including: disproportionation, carbonylation, carboxylation and biocatalysis methods. The paper also summarizes a comparative analysis of the advantages and disadvantages of each method and highlights the progress made in their respective research fields. A comparative analysis indicates that the C-H carboxylation method is a gentle and environmentally friendly process, demonstrating significant potential for large-scale production. Figures and Tables | References | Related Articles | Metrics

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Optimization of Ultrasonic-assisted Extraction Technology of Saponins from Gleditsia sinensis Thorn by RSM and Its Hypoglycemic Activity Yong LIU, Caihong ZHANG, Pujun XIE, Yejun DENG, Lixin HUANG 2023, 43 (2):  12-18.  doi: 10.3969/j.issn.0253-2417.2023.02.002 Abstract ( 346 )   HTML ( 18 )   PDF (1750KB) ( 313 )   Save On the basis of single factor experiment, response surface methodology(RSM) was used to optimize the ultrasonic-assisted extraction optimum process of saponins from Gleditsia sinensis Thorn(GST), and the inhibitory activities of the extracts on α-glucosidase and α-amylase were investigated under the optimal extraction conditions. The results showed that the optimal ultrasonic-assisted extraction conditions were solid-liquid ratio of 16:1(mL: g), ethanol volume fraction of 60%, ultrasonic time of 80 min and extraction temperature of 50℃. Under these conditions, the yield of total saponins was 13.28%±0.25%, and the IC50 value of α-glucosidase was (0.146±0.019) g/L, which was stronger than that of positive control acarbose with the median inhibitory concentration(IC50) value of (0.48±0.18) g/L. When the mass concentration of the extract was 2 g/L, the inhibition rate of α-amylase could reach 35.13%±0.58%, indicating that GST had the potential development into a drug for type II diabetes. Figures and Tables | References | Related Articles | Metrics

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Preparation of Rhododendron×pulchrum Sweet Flowers Anthocyanins Microcapsule and Its Stability Mei ZHANG, Yanjie ZHANG, Weijian CHEN, Huafang JING, Benyong LOU 2023, 43 (2):  19-26.  doi: 10.3969/j.issn.0253-2417.2023.02.003 Abstract ( 147 )   HTML ( 8 )   PDF (2930KB) ( 318 )   Save In order to improve the stability of anthocyanins and broaden their application in functional products, the preparation process of Rhododendron pulchrum flowers anthocyanin microcapsules was optimized by response surface methodology, which was made using gum acacia and whey protein as wall materials and anthocyanin as core material. The anthocyanin microcapsules were characterized by scanning electron microscope(SEM), Fourier infrared spectroscopy(FT-IR) and thermogravimetry(TG). The results showed that the optimal microencapsulation conditions for the preparation of anthocyanin microcapsules by spray drying were as follows: wall-core ratio of 4:1, inlet air temperature of 165℃, and feed flow of 500 mL/h. Under these conditions, the embedding rate of anthocyanin microcapsules was(89.28±1.05)%. SEM showed that anthocyanin microcapsules were uniform spherical particles with a diameter of about 4.0 μm, compact structure, no cracks and non-sticking. FT-IR analysis showed that R. pulchium anthocyanins was embedded in the film formed by gum acacia and whey protein. TG analysis showed that the quality of anthocyanins decreased significantly at 197.7℃. Comparatively, the significant mass loss of anthocyanin microcapsules could be found only at 237.5℃. The storage stability analysis showed that the retention rate of R. pulchium flowers anthocyanin microcapsules was significantly higher than that of unembedded anthocyanins owing to the influence of light and temperature. Figures and Tables | References | Related Articles | Metrics

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Improving the Quality of Biofuel by Torrefaction Yunhong SU, Jurong REN, Yunjuan SUN, Jianchun JIANG, Le XU 2023, 43 (2):  27-35.  doi: 10.3969/j.issn.0253-2417.2023.02.004 Abstract ( 168 )   HTML ( 3 )   PDF (3729KB) ( 309 )   Save The effect of torrefaction on the quality of biofuel was investigated through a small torrefaction experimental equipment with rice husk(RH) and pine sawdust(PS) as the raw materials. The results showed that torrefied rice husk and sawdust exhibited an increase in fixed carbon content by 7.18% and 11.76%, compared with the raw materials. And the C element content with the largest increased of 3.50% and 5.80% for rice husk and sawdust, respectively. The contents of volatile matter and O element decreased significantly, and the content of H element also decreased slightly. The calorific value increased by 11.1%(RH) and 15.9%(PS), respectively. The hemicellulose contents in the torrefied rice husk and sawdust after reaching 300℃ were only 2.41% and 1.06%, respectively. The hemicellulose was decomposed both more than 90%. The relative content of lignin increased significantly, with the largest increases of 119%(RH) and 208%(PS), respectively. After biomass torrefaction, the internal fiber structure was destroyed and the grindability was improved. With the deepening of the torrefaction degree, the particles with the size below 0.15 mm increased significantly after torrefied rice husk being ground. The study found that oxygen-containing functional groups such as -OH and C-O were reduced, and the hydrophobicity of torrefied rice husk and sawdust increased by 28.08% and 25.66%, respectively, when torrefied at 250℃ for 30 min. Figures and Tables | References | Related Articles | Metrics

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Preparation of Antifreezing Soybean Protein-based Gel Electrolytes and Application in Electrochemical Capacitors Fusheng YANG, Dingkun WANG, Fapeng WANG, Meihong LIU, Jingya NAN, Chunpeng WANG 2023, 43 (2):  36-42.  doi: 10.3969/j.issn.0253-2417.2023.02.005 Abstract ( 162 )   HTML ( 13 )   PDF (3316KB) ( 269 )   Save An antifreezing soybean protein-based gel electrolyte was prepared by thermally induced polymerization using soybean protein(SPI), acrylamide(AAm) and ZnCl2 as raw materials. The effect of temperature on its ionic conductivity and mechanical property was investigated, and the mechanism was then analyzed. The results showed that the gel electrolyte had excellent frost resistance, and the introduction of ZnCl2 leaded to the formation of numerous Zn2+ solvation structures, which broke the hydrogen bonds among water molecules and reduced the freezing point of gel electrolyte. The synergistic effect of gel matrix and salt ions gave the gel electrolyte high compression resilience and fatigue resistance. The analysis of low-temperature ionic conductivity showed that when the ZnCl2 concentration exceeded 5 mol/kg, the ionic conductivity of gel electrolyte was still 3.65×10-3 S/cm at -30℃. The analysis of mechanical properties at low temperatures showed that the gel electrolyte could keep structural integrity after 100 compression cycles of 80% strain at -30℃, the stress retention remained more than 85% and the plastic deformation maintained 15%. At the same time, the gel electrolyte-based electrochemical capacitors assembled by gel electrolyte exhibited satisfied low-temperature resistance, which could work normally at -30℃ and maintain capacitance retention of 83.2%. The capacitance retention reached 92% after 10 000 cycles of charge and discharge at -30℃. Figures and Tables | References | Related Articles | Metrics

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Effect of Acetic Acid on Ethanol Pulping and Pulp Properties of Bambusa pervariabilis Hongshuang BAI, Qingwei PING, Xueru SHENG, Jian ZHANG, Na LI, Haiqiang SHI 2023, 43 (2):  43-48.  doi: 10.3969/j.issn.0253-2417.2023.02.006 Abstract ( 186 )   HTML ( 3 )   PDF (518KB) ( 281 )   Save Using Bambusa pervariabilis as the raw materials the effects of acetic acid on the pulp yield, hardness, fiber crystallinity, fiber morphology and paper performance in ethanol pulping were studied. The results showed that the pH value of the solution decreased significantly from 7.3 to 4.1 after 2.0% acetic acid was added. The yield of coarse pulp decreased from 46.64% to 43.14%, which accelerated the degradation of carbohydrates. The Kappa number of pulp decreased from 52.31 to 48.90, which promoted the lignin removal during cooking. The relative molecular weight of lignin increased when the dosage of acetic acid was lower than 6%, while the relative molecular weight of lignin reduced when the dosage of acetic acid was higher than 6%. The addition of acetic acid made the coexistence of lignin degradation or condensation. The average length of the double mass(Lw) decreased from 1.72 to 1.58 mm, and the average width of the doublemass(Ww) decreased from 25.27 to 19.37 μm, which could make the fiber shrink and hard. The loose thickness and tear index of the finished paper were improved after adding acetic acid. The loose thickness increased from 2.16 to 2.30 cm3/g, and the tear index increased from 130.67 to 133.33(mN·m2)/g. The tensile index, flexability and break resistance decreased significantly. The tensile index decreased from 19.06 to 14.37(N·m)/g, the flexability decreased from 6 times to 3 times, and the break index decreased from 1.0 to 0.7 (kPa·m2)/g. The fiber crystallinity decreased from 54.67% to 48.71%. Acetic acid would destroy the fiber crystal zone, and the fiber crystallinity gradually decreased with the increase of acetic acid dosage, while the crystal zones of natural cellulose did not change. Figures and Tables | References | Related Articles | Metrics

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Preparation and Properties of Pressure Sensitive Adhesives Derived from Rosin Bio-based Acrylate Simai QI, Tong LUO, Meihong LIU, Chunpeng WANG, Fuxiang CHU, Jifu WANG 2023, 43 (2):  49-55.  doi: 10.3969/j.issn.0253-2417.2023.02.007 Abstract ( 294 )   HTML ( 6 )   PDF (1706KB) ( 404 )   Save In this work, furfural-based monomer tetrahydrofurfuryl methacrylate(THFMA), disproportionated rosin-based monomer(DRM), and oil-based monomer lauryl methacrylate(LMA) were used as raw materials to prepare a series of bio-based pressure-sensitive adhesives(PSA) based on THFMA/DRM/LMA by solution polymerization method. The effects of hard monomer and soft monomer composition ratio and the monomer molecular structure on the performance of PSA were investigated in detail. The results showed that the adhesion increased from 0.48 to 72 h with the increase of hard monomer THFMA in PSA from 10% to 50%. When the content of THFMA was 30%, the comprehensive performance of PSA was the best. The tack of THFMA30-LMA was 2.28 N, the 180° peel strength was 143.6 N/m, and the shear resistance reached 21.25 h. In addition, compared with THFMA, using DRM as hard monomer could enhance the mechanical properties of PSA and improve the thermal stability of PSA. Figures and Tables | References | Related Articles | Metrics

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Synthesis and Electrochemical Properties of Biomass Mesoporous Carbon Doped with Nitrogen and Phosphorus Bo ZHANG, Xiang LI, Wei LIU, Xiaoli LI 2023, 43 (2):  56-62.  doi: 10.3969/j.issn.0253-2417.2023.02.008 Abstract ( 150 )   HTML ( 11 )   PDF (2391KB) ( 272 )   Save Nitrogen and phosphorus doped mesoporous carbon(NPC) materials were prepared by carbonization activation at different temperatures, using lignocellulose as raw material, hexa p-carboxylphenoxy cyclotriphosphazene(HCPCP) as nitrogen and phosphorus dopant with NaOH as coactivator, and were characterized by SEM, XRD, XPS and Raman spectra. The sample activated at 650℃(NPC-650) exhibited a rich reticular pore structure, with the average pore size of 5.18 nm, and the mesopore volume ratioreached 89%. A new zinc ion hybrid capacitor was assembled using NPC-650 as cathode material. Electrochemical performance tests showed the specific capacitance was 194 F/g at 0.2 A/gcurrent density, the energy density was 87.3(W·h)/kg, and the power density was 179.5 W/kg. The capacitance retention rate was 98.9% after 5 000 charging and discharging cycles under the current density of 10 A/g. Figures and Tables | References | Related Articles | Metrics

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Catalytic Conversion of Aromatic Hydrocarbon-based Hydrogen Carriers to Produce Hydrogen Wenxuan CHEN, Xueqin LI, Peng LIU, Tingzhou LEI, Yanling LI, Youqing WU 2023, 43 (2):  63-72.  doi: 10.3969/j.issn.0253-2417.2023.02.009 Abstract ( 144 )   HTML ( 8 )   PDF (2768KB) ( 214 )   Save Nickel-based supported molecular sieve catalysts were prepared by excessive impregnation with different auxiliary methods using molecular sieve as the carrier. The catalytic pyrolysis performance of the nickel-based molecular sieve catalysts on the hydrogen carrier of biomass tar aromatic hydrocarbon-toluene to produce hydrogen was studied in a fixed-bed reactor. The effects of different molecular sieves, auxiliary methods and process conditions were investigated, and the service life of the catalyst was studied. The catalysts were characterized by XRD, SEM and BET. The results showed that the Ni/HZSM-5 molecular sieve catalyst using HZSM-5(the ratio of silicon to aluminum was 25) zeolite as the carrier had the highest catalytic activity, through the ultrasonic-assisted impregnation method, and the ultrasonic time was 20 min, the ultrasonic power was 80 W, and the Ni loading was 8%. At 700℃ and 40 min, the yields of H2 and CH4 were 76.6 mL/g and 27.6 mL/g, respectirely, and the total gas yield reached 108.9 mL/g. The toluene conversion rate was 76.8%, and the carbon deposition was 238.2 mg/g. The specificsurface area, the total pore volume and the average pore size of the catalyst were 241.8 m2/g, 0.19 cm3/g and 3.16 nm, respectively. The Ni loading did not affect the crystal structure of HZSM-5 obviously, while it exhibited an excellent catalytic activity. The stability of Ni/HZSM-5 catalyst was improved, and the service life was also extended. The catalytic hydrogen production performance of toluene was better than that of tetralin, phenol and acetic acid. Figures and Tables | References | Related Articles | Metrics

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Preparation and Properties of Menthane Diamine Vitrimer Based on Dynamic Ester Bonds Songlin DAI, Yazhou XU, Haibo ZHANG, Zhendong ZHAO, Jing WANG, Yuxiang CHEN 2023, 43 (2):  73-79.  doi: 10.3969/j.issn.0253-2417.2023.02.010 Abstract ( 154 )   HTML ( 8 )   PDF (866KB) ( 201 )   Save Bio-based glass-like polymer(vitrimers) materials based on dynamic transesterification mechanism were prepared by the adduct of eleostearic acid and maleic anhydride(EMA) and epoxidizing menthane diamine(EMDA) derived from menthane diamine(MDA). The obtained materials were characterized and tested by Fourier transform infrared spectroscopy(FT-IR), dynamic thermomechanical analysis(DMA), thermogravimetric(TG) analysis, universal testing machine and other testing methods. The experimental results showed that the tensile strength of the materials was up to 35 MPa, the elongation at break was up to 12%, the 5% weight loss temperature was up to 264℃, and the glass transition temperature(Tg) was up to 119℃. The crossliking density increased first and then decreased with the increasing content of epoxidized menthane diamine. The materials had Tg-based shape memory ability and under went topological rearrangement of cross-linked structure at 180℃.The degradation of the material was achieved by the reaction of ethanolamine with the ester bond in the materials, and it was proved by gel permeation chromatography(GPC) that the materials could be degraded into oligomers with Mn of 2 594 and PDI of 1.09 at 130℃ for 8 h. Figures and Tables | References | Related Articles | Metrics

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Preparation of Dispersant and Water Absorption Resin by Staged Conversion from Furfural Residue Gang GUI, Xiaoru WANG, Lu ZHANG, Chaojun DU, Wei CHEN, Chun CHANG 2023, 43 (2):  80-88.  doi: 10.3969/j.issn.0253-2417.2023.02.011 Abstract ( 154 )   HTML ( 1 )   PDF (2495KB) ( 247 )   Save Using the staged conversion strategy, the lignin component in furfural residue(FR) was first prepared into lignin-based dispersant(LS). When the mass of FR was 100 g, the mass of the deionized water was 1 000 g, the reaction temperature was 70℃, the reaction time was 3 h, the dosage of sodium hydroxide was 6.5 g, sodium sulfite dosage was 1.6 g, and formaldehyde dosage was 0.2 g, the dispersing force of LS was 105%. Subsequently, water absorption resin was further prepared from the separated cellulose residue. The effects of the reaction temperature, the amount of initiator ammonium sulfate(APS), crosslinking agent N, N'-methylene bisacrylamide(MBA) and the total amount of complex monomer acrylic acid(AA) and acrylamide(AM) on the water absorption of the water-absorbing resin were investigated. Under the optimum conditions of the neutralization degree of acrylic acid of 60%, the initiation time of 0.5 h, the amount of complex monomer of 9 g, the amount of initiator of 1.3 g, crosslinking agent dosage of 0.05 g, the reaction temperature of 52℃, and the graft copolymerization reaction time of 3 h, the water absorption of the water absorbent resin reached 64.6 g/g. FT-IR analysis showed that the grafting reaction of AM, AA and cellulose residue occurred. SEM images showed that theproduct with cross-linked network structure was formed in the reaction; thermogravimetric analysis showed that the introduction of AA and AM improved the thermal stability of the water absorbent resin; XRD revealed that the grafting reaction of AA and AM took place on the skeleton of cellulose residue. Figures and Tables | References | Related Articles | Metrics

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Change Law of Pigments Content of Ginkgo biloba Leaves in the Different Months and Dry Modes Analyzed by HPLC-DAD Method Hong SHEN, Changwei ZHANG, Hongxia CHEN, Hua YUAN, Jianxin JIANG, Chengzhang WANG 2023, 43 (2):  89-97.  doi: 10.3969/j.issn.0253-2417.2023.02.012 Abstract ( 169 )   HTML ( 5 )   PDF (742KB) ( 198 )   Save HPLC-DAD method was used to study the change law of content of Ginkgo biloba leaves pigments in different months, and the effects of various drying methods on the content of G.biloba leaves pigments were evaluated by cluster analysis and technique for order preference by similarity to an ideal solution(TOPSIS). The results showed that the established HPLC-DAD method was simple, accurate, sensitive and reproducible. G. biloba leaves pigments content was significantly different from April to November. The contents of chlorophylide a, pheophorbidel a and β-carotene reached the highest values in April, which were (1 762±121), (628±32) and (482±45) μg/g, respectively. The contents of chlorophyll a and b arrived at the highest values in May, which were (8 701±571) and(3 140±274) μg/g, respectively. The content of lutein could get to the highest value in July, which was (2 057±104) μg/g. Cluster analysis results demonstrated that 12 kinds of drying methods could be divided into four categories. Freeze drying, vacuum drying at 40℃, and atmospheric drying at 40℃ were clustered as A category. Shade drying was clustered as B category. vacuum drying at 100℃ and atmospheric drying at 100℃ were clustered as D category. The left 6 kinds of drying methods were clustered as C category. Through the analysis of TOPSIS method, it was found that the top five drying methods of G. biloba leaves were freeze drying, vacuum drying at 40℃, atmospheric drying at 40℃, shade drying and atmospheric drying at 60℃. Considering comprehensively, vacuum drying at 40℃ was the most suitable drying method for industrial production, with fast drying speed and effective protection of pigments. Figures and Tables | References | Related Articles | Metrics

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Ultrasound-assisted Fenton-like Pretreatment of Eucalyptus for Enhancing Enzymolysis Mengjie CHEN, Zhinan WANG, Shujie WANG, Yingshi HUANG, Xianfeng HOU, Zhenzhong GAO 2023, 43 (2):  98-104, 126.  doi: 10.3969/j.issn.0253-2417.2023.02.013 Abstract ( 125 )   HTML ( 4 )   PDF (3102KB) ( 190 )   Save To overcome problems in traditional Fenton pretreatment, an ultrasonic-assisted iron-loaded zeolite Fenton-like(UZF) system was constructed, and single factor method was used to determine optimal conditions for UZF pretreatment of eucalyptus, i.e., H2O2 concentration of 4%, ultrasonic power of 240 W, and treatment time of 90 min. Under these conditions, the reducing sugar produced by enzymatic enzymolysis of eucalyptus powder was as high as (435.12±7.69) mg/g. The mechanism of UZF pretreatment to enhance enzymolysis efficiency of eucalyptus was investigated by means of composition, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy(SEM). The changes of main components and groups, crystalline properties, and surface microstructure of eucalyptus samples before and after UZF pretreatment were analyzed. The results showed that pretreatment removed more lignin and hemicellulose, which increased destruction of amorphous area of cellulose, and surface holes of wood powder became more and surface was more rough. The experimental results of recycling showed that the iron-loaded zeolite had certain recycling ability. After four times of recycling, reducing sugar yield could still reach 1.87 times than that of untreated eucalyptus powder. Figures and Tables | References | Related Articles | Metrics

 

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Anatomical Structure of Gelsemium elegans Benth and the Antibacterial Action of Alkaloids Meng ZHAO, Meiling LU, Yating ZHAO, Yunxia WANG, Qiongqiong XUE, Xueqin WANG 2023, 43 (2):  105-115.  doi: 10.3969/j.issn.0253-2417.2023.02.014 Abstract ( 166 )   HTML ( 8 )   PDF (15336KB) ( 254 )   Save In the present study, the microstructure of Gelsemium elegans vegetative organs was observed, and the alkaloids in plants were localized. Also, the antibacterial activity of the alkaloids was explored, and the antibacterial mechanism of the alkaloids was analyzed. The anatomical study of the structural characteristics of G. elegans vegetative organs was carried out with anatomical methods, and through histochemical staining, the alkaloids in the plant were localized. Microscopic observation results showed that the structure of G. elegans performed the typical characteristics of the dicotyledonous plants; the leaf of G. elegans was dorsiventral, and there were starch granules deposited in stem pith. The histochemical results showed that the vegetative organs of G. elegans contained alkaloids. Alkaloids were mainly distributed in the mesophyll tissue of leaves. In the stem, alkaloids were mainly distributed in stem epidermis, cortex cells and phloem parenchyma cells. Also, alkaloids were distributed in parenchyma cells of pith and ray cells. Yellow-brown sedimentation also could be observed in the cork cambium, the inner layer, the cortex, phloem parenchyma and ray cells of the rhizome. The antibacterial activity results showed that the G. elegans alkaloid had antibacterial activity against Listeria monocytogenes ATCC19115, Staphylococcus aureus ATCC25923, Staphylococcus aureus CMCC26003, Escherichia coli ATCC25922, Escherichia coli O157, Pseudomonas aeruginosa ATCC27853, and Pseudomonas aeruginosa CMCC10104. With the increase of alkaloid concentration, the antibacterial effect was also enhanced. The inhibitory effect on Listeria monocytogenes was the most obvious. After treatment with its minimum inhibitory and lethal concentrations, the morphology and internal structure of Staphylococcus aureus ATCC25923 and Escherichia coli O157 showed that both two kinds of bacteria changed in different degrees, such as rough surface, depression, rupture of the cell membrane and cell wall, overflow of internal substance and even cell lysis. The morphology of S. aureus changed at the minimum inhibitory concentration and the cell wall of E. coli was stratified. This indicated that G. elegans alkaloid destroyed the permeability of the cell membrane, impeded the formation of the cell wall, and lysed the bacteria. The cell death at the minimum lethal concentration might be caused by the loss and cleavage of the mechanical strength and permeability of the wall. Figures and Tables | References | Related Articles | Metrics

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Preparation of Porous Graphite Carbon Nitride and Its Visible Light Catalytic Conversion of Lignin Chunyu REN, Xiangyu LIN, Zhuomin WANG, He LIU 2023, 43 (2):  116-126.  doi: 10.3969/j.issn.0253-2417.2023.02.015 Abstract ( 182 )   HTML ( 11 )   PDF (5398KB) ( 332 )   Save Porous graphitic carbon nitride(mpg-CN) material with large surface area(126.6 m2/g) was successfully prepared by removing silica from a graphitic carbon nitride(g-C3N4)/silica composite, where the latter was synthesized using urea and tetraethyl orthosilicate(TEOS) as precursors through thermal polycondensation. Nitrogen adsorption-desorption isotherm, SEM, TEM, XRD, ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS), photoluminescence spectroscopy(PL) and electrochemical impedance spectroscopy(EIS) were used to analyze the internal structure, physical morphology, crystalline form and photoelectrical properties of the catalyst. The results showed that the introduction of TEOS had almost no effect on the crystal structure and band gap of the catalyst, while it could increase the specific surface area, pore volume and pore size of mpg-CN, thus providing more active sites. mpg-CN had lower photogenerated carrier recombination rate, higher photogenerated carrier separation efficiency and mobility, which was beneficial to the improvement of photocatalytic activity. To test the photocatalytic activity and product selectivity of the catalyst with different atmospheres and solvents conditions, a lignin model compound 1(2-phenoxy-1-phenylethanol) was used as the substrate. The results showed that under the conditions of catalyst mpg-CN, illumination, O2 atmosphere and solvent of CH3CN for 7.5 h, the conversion rate of 2-phenoxy-1-phenylethanol can reach 98.06%, and the selectivity of C-C bond cleavage was 91.79%. The result of the capture experiment proved that the photo-generated hole(h+) was the main active substance in the induced reactions. mpg-CN also had good stability and recycling performance, and the conversion rate of model compound 1 was 93%-98% when it was recycled for 1-8 times. Furthermore, the catalyst also showed a high conversion rate of 93.18% for the photocatalytic conversion of complex dimer lignin model compound 1b(1-(3-methoxyphenyl)-2-(2-methoxyphenoxy)-propane-1-diol). Figures and Tables | References | Related Articles | Metrics

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Preparation of Bamboo Pulp Fiber Hydrothermal Carbon Microspheres with Controllable Structure Shitao WEN, Linxin DAI, Zhihui WANG, Zhenrui LI, Jiajun WANG, Xing'er LIU 2023, 43 (2):  127-134.  doi: 10.3969/j.issn.0253-2417.2023.02.016 Abstract ( 163 )   HTML ( 7 )   PDF (6586KB) ( 246 )   Save In order to realize the preparation of morphologically controllable hydrothermal carbon microspheres, the effects of hydrothermal reaction conditions(reaction temperature, reaction time and reactant addition) on the morphology and physicochemical structure of the products were systematically studied using bamboo pulp fiber as a raw material. The obtained hydrothermal carbon was investigated by SEM, XRD, FT-IR and other characterization methods. The results showed that when the reaction temperature was 220℃, the reaction time was 6 h and the amount of reactant was 6 g, the carbon microspheres were dispersed and the size distribution was relatively uniform. The highest carbon fixation rate of the sample reached 24.3%, indicating that the preparation of hydrothermal carbon had a good carbon fixation ability. XRD results showed that hydrothermal carbon was an amorphous crystal. Functional gronp analysis showed that the surface of hydrothermal carbon was rich in a series ofoxygen-containing functional groups such as hydroxyl, carbonyl, ester and ether bonds. Elemental analysis showed that hydrothermal carbon had preferably carbon fixation ability. The specific surface area of the products ranged from 23.2-83.7 m2/g, and the pores were mainly mesopores. The main distribution range was 3-8 nm, and the maximum pore volume was 0.35 cm3/g. Figures and Tables | References | Related Articles | Metrics

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Enzymatic Digestibility of Ternary Deep Eutectic Solvent Pretreated Sugarcane Bagasse Shunhui TAO, Kexuan ZHANG, Biying LI, Xiaojie ZHENG, Yao LIU, Xiaoqing LIN 2023, 43 (2):  135-142.  doi: 10.3969/j.issn.0253-2417.2023.02.017 Abstract ( 169 )   HTML ( 3 )   PDF (2476KB) ( 269 )   Save Sugarcane bagasse(SCB), a by-product of the sugar industry, was used as a lignocellulosic raw material. In the present study, a ternary deep eutectic solvent(DES) composed of triethylbenzyl ammonium chloride(TEBAC) with strong phase transfer catalytic ability, non-toxic and harmless glycerol(GL) and high-valence Lewis acid aluminum chloride hexahydrate(ACH), was used to pretreat SCB. The effects of molar ratio of ternary DES, reaction temperature, reaction time and solid-liquid mass ratio on the content of each component in SCB and cellulase enzymatic digestibility were systematically investigated. The results showed that the optimal pretreatment conditions were as follows: the molar ratio of nTEBAC: nGL: nACH was 1:2:0.05, the pretreatment time was 30 min, the pretreatment temperature was 120℃ and the solid-liquid ratio was 1:15. Under these conditions, the lignin removal rate was (86.23±2.11)%, and the cellulose retention rate was (94.51±2.03)%. The conversion of enzymatic hydrolysis cellulose was (98.21±1.02)%, which was 2 times higher than that of untreated SCB, and the yield of glucose was(81.94±1.98)%, which was increased by 1.5 times. The results of SEM, FT-IR and XRD analysisshowed that ternary DES pretreatment could effectively remove lignin and hemicellulose from SCB, and the crystallinity of celluloseincreased from 41.19% to 65.87% after pretreatment. Importantly, DES still maintained good pretreatment performance after 5cycles of recycling, and the cellulose conversion rate and glucose yield reached (92.36±1.64)% and (74.45±1.12)%, respectively. Figures and Tables | References | Related Articles | Metrics

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Preparation of Amphoteric Cellulose Based Adsorbent and Its Removal of Nitrogen and Phosphorus Pollutants from Wastewater Yingnan SUN, Suzhen LIU, Haiming LI, Jingpeng ZHOU, Fengshan ZHANG, Yanzhu GUO 2023, 43 (2):  143-152.  doi: 10.3969/j.issn.0253-2417.2023.02.018 Abstract ( 171 )   HTML ( 9 )   PDF (7407KB) ( 315 )   Save Amphoteric cellulose copolymers(CO-AC) adsorbents were prepared though free radical polymerization in one-pot process using cellulose as raw material and methacryloxyethyl trimethyl ammonium chloride(METAC), acrylamide(AM), 2-acryloamino-2-methyl-1-propane sulfonic acid(AMPS) as monomers and potassium persulfate as initiator. The structure and properties of CO-AC were characterized by elemental analyzer and fourier infrared spectrometer(FT-IR). It was found that active groups, e.g., quaternary amine, amide and sulfonic acid group were successfully introduced into the molecular chains of cellulose. Taking the removal rate and equilibrium adsorption capacity of CO-AC to NH4+ and H2PO4- as the evaluation indexes, the adsorption conditions were optimized and the influence of various factors on the adsorption capacity of CO-AC were also evaluated. The results showed that the adsorption capacity of the adsorbent, derived under the conditions of 1:2:3:3 molar ratio of cellulose glucose unit to AMPS, AM and METAC, was the best. In 50 mL of NH4+ and H2PO4- solution with a mass concentration of 150 mg/L, the maximum adsorption capacity of NH4+ was 77.4 mg/g when the addition amount of CO-AC was 100 mg and pH value was 7.0. The maximum adsorption capacity of H2PO4- was 61.2 mg/g, while the addition amount was 100 mg and the pH value was 5.0. The adsorption process of NH4+ and H2PO4- on CO-AC was well characterized by the quasi-second-order kinetic, internal diffusion of particle and Langmuir models, indicating that chemisorption and internal particle diffusion processes were the main rate-limiting steps, and the adsorption process was homogeneous monolayer adsorption. Figures and Tables | References | Related Articles | Metrics

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Research Progress of Chemical Constituents and Pharmacological Effects of Euscaphis Plants Liangjie TANG, Wei LUO, Hulan CHEN 2023, 43 (2):  153-170.  doi: 10.3969/j.issn.0253-2417.2023.02.019 Abstract ( 181 )   HTML ( 8 )   PDF (1535KB) ( 306 )   Save The main chemical constituents of Euscaphis plants are triterpenoids, phenolic acids, flavonoids, lignans, sesquiterpenoids, etc. Modern research shown that the extracts and monomeric compounds of the Euscaphis plants had anti-inflammatory, anti-bacterial, anti-tumour, anti-hepatic fibrosis and other pharmacological effects. At present, species delimitation of Euscaphis was changed and it was not very clear whether there were differences in chemical composition between the different varieties. Through the systematic search and summary of the chemical composition and pharmacological effects of Euscaphis plants, and we deeply elaborated whether differences in chemical composition was existed between different species and possible differential components, in order to provide a reference for the classification, development and use of Euscaphis plants. Figures and Tables | References | Related Articles | Metrics