Table of Content

28 August 2023, Volume 43 Issue 4 Previous Issue    Next Issue

Select

Preparation and Characterization of High Performance Formed Activated Carbon by Modification of By-products from Bamboo Gasification Ruting XU, Mingzhe MA, Hao YING, Hao SUN, Yanren JIN, Ting ZHAO 2023, 43 (4):  1-8.  doi: 10.3969/j.issn.0253-2417.2023.04.001 Abstract ( 301 )   HTML ( 33 )   Save Using carbon by-products produced by bamboo gasification as raw material and the polymerized modified tar as the binder, the bamboo formed activated carbon was obtained by hydro-forming, pyrolytic cross-linking and followed by water vapor activation. The forming mechanism of different binders were analyzed, and the properties of activated carbon were investigated, such as the variety of the binder, the adding amount of modified tar, the activation temperature and the activation time. The results showed that after modification by aromatization and cross-linking, the molecular weight and thermal stability of tar were improved; the blocking effect of bamboo char pore channels was reduced; the bonding and pyrolytic cross-linking between char particles were enhanced; and high-performance bamboo forming activated carbon could be prepared. Using 40g bamboo charcoal as raw material, the tar addition amount of 12 g, the carbonization temperature of 550 ℃, the carbonization time of 90 min, the activation temperature of 850 ℃ and the activation time of 80 min, the iodine adsorption value of the formed carbon was 1 232 mg/g, the methylene blue(MB) adsorption value was 240 mg/g, the strength was 91%, and the yield was 48.5%. The specific surface area and total pore volume were 1 157 m2/g and 0.478 1 cm3, respectively. The adsorption rates of toluene and carbon tetrechloride were 385 mg/g and 75.2%, respectively. And the adsorption rate of toluene and carbon tetrechloride was positively related to the micropore volume of formed activated carbon. References | Related Articles | Metrics

Select

Characterization of Choline Chloride/Urea Pretreated Rice Straw and Its Dissociative Fiber Structure and Properties Xiaodong FAN, Shanming HAN, Ping QU, Hongying HUANG, Enhui SUN, Shengcheng ZHAI 2023, 43 (4):  9-16.  doi: 10.3969/j.issn.0253-2417.2023.04.002 Abstract ( 146 )   HTML ( 11 )   PDF (8602KB) ( 218 )   Save The rice straw was pretreated by choline chloride/urea deep eutectic solvent(DES) system, and the pretreated straw fiber was dissociated by mechanical homogenization treatment. With the DES addition of 1.5%, 2.5%, 3.5% and 4.5% of the straw mass, the prepared dissociated fiber slurries were labeled as DES-1.5%, DES-2.5%, DES-3.5% and DES-4.5%, respectively, while the sample without DES treatment was used as the control(CK). The properties of the dissociated fibers were characterized by Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD), scanning electron microscopy(SEM) and fluorescence microscopy. The chemical composition of the dissociated fibers treated by different methods was analyzed by NREL method, and the mechanical energy consumption of the disc mill and the film-forming mechanical properties of the dissociated fibers were studied. The results showed that the homogenization pretreatment of DES system combined with disc grinding machine could destroy the connection of LCC through the competition of hydrogen bonds, thus promoting the dissociation of straw fibers and facilitating the fibrillation of fibers. Compared with CK, when the addition amount of DES was 3.5%, the microfibril angle and crystallinity increased from 35.84° and 41.3% to 47.61° and 50.1%, respectively, in addition to a lignin content decrease by 5.3 percentage points. Moreover, the fracture of the surface layer of rice straw fiber increased, and the energy consumption of disc milling decreased by 160 kW·h/t. The straw fiber mulch prepared under this condition had the best weighted mechanical properties. The results of fluorescence microscopy showed that DES pretreatment could accelerate the migration and dissolution of lignin to the surface of straw fiber. Figures and Tables | References | Related Articles | Metrics

Select

Effect of Acid Generated During Autohydrolysis of Acacia Wood on the Subsequent Kraft Pulping Jiahui SONG, Miaofang ZHOU, Wenchao JIA, Tianci LIU, Haiqiang SHI 2023, 43 (4):  17-24.  doi: 10.3969/j.issn.0253-2417.2023.04.003 Abstract ( 124 )   HTML ( 5 )   PDF (607KB) ( 200 )   Save In order to study the acid generation of Acacia wood during autohydrolysis and its influence on the chemical properties of sulfate pulping of hydrolyzed wood chips, the wood chips autohydrolysis was pretreated in the P severity range of 93-1 008. Then, a part of the pretreated wood chips were washed by ultrasonic wave to remove the residual acid. The pre-impregnated wood chips treated with acid removal and the control sample(i.e. without ultrasonic treatment) were sulfate pulped under the same conditions. The results showed that the content of acid in autohydrolysate(AHL) increased with the increase of pretreatment intensity, resulting in the pH value of AHL decreased. Among them, acetic acid was the main acid component. The concentration of acetic acid reached 4.21 g/L at P factor of 606, which slowly increased to 4.41 g/L at 1 008, and a small amount of formic acid was also detected. The results showed that the pulp yield of wood chips increased by 10.1% after ultrasonic washing, and the Kappa value of pulp decreased from 31.2 to 19.7 when the P factor was 1 008. The pulp viscosity did not change significantly, while the fiber length decreased from 0.76 mm to 0.64 mm at the P factor of 1 008, which may be the reason of the slight decrease in the tensile and breaking strength of wood chips after ultrasonic washing. Figures and Tables | References | Related Articles | Metrics

Select

The Antibacterial Activity and Mechanism of Hydronopyl Quaternary Ammonium Compounds Qingying DING, Jiayu CHANG, Zhuanquan XIAO, Guorong FAN, Zongde WANG, Shangxing CHEN 2023, 43 (4):  25-30.  doi: 10.3969/j.issn.0253-2417.2023.04.004 Abstract ( 137 )   HTML ( 15 )   PDF (471KB) ( 231 )   Save In this work, we adopted β-pinene, which was one of the main components of turpentine oil, to synthesize 36 quaternary ammonium compounds including hydronopyl monoquaternary ammonium salts(1-13), dihydronopyl monoquaternary ammonium salts(14-18) and symmetric dihydronopyl bis-quaternary ammonium salts(19-36). The minimum inhibitory concentrations(MIC) of these compounds against four harmful bacteria such as Escherichia coli, Pseudomonas putida, Staphylococcus aureus and Bacillus subtilis were tested by 96-well microtiter plates, using resazurin as chromogenic agent and kanamycin sulfate as the positive control. The results showed that the antibacterial activities of the synthesized quaternary ammonium compounds were significantly higher than that of the starting material β-pinene and the critical intermediate hydronol. The monoquaternary ammonium salts with hydronopyl and long carbon chain alkyl(10-11), the monoquaternary ammonium salts with dihydronopyl(14-18), and the symmetric dihydronopyl bis-quaternary ammonium salts(19-36) had high antibacterial activity, while the MIC values of most quaternary ammonium compounds were higher than those of kanamycin sulfate(the MIC values against P. putida and the other three bacteria are 10 mg/L and 5 mg/L, respectively). The MIC values of dihydronobuyl dimethyl ammonium bromide(14) against P. putida, S. aureus and B. subtilis were 1.25 mg/L, 2.5 mg/L, 2.5 mg/L, respectively, and the MIC value of dihydronobuyl diethyl ammonium bromide(16) against P. putida was 2.5 mg/L, which was lower than the MIC value of the positive control kanamycin sulfate. Furthermore, the preliminary antibacterial mechanism studies revealed that compound 14 increased the permeability of P. putida cell membranes, resulting in a significant increase in relative conductivity, and at the same time, inhibiting its ATP activity. These hydronopyl quaternary ammonium compounds were expected to be used as potential antimicrobial agents. Figures and Tables | References | Related Articles | Metrics

Select

Process Optimization and Demonstration Engineering on Producing Medium Heat Value Bio-gas Through Biomass Oxygen Gasification Wei XU, Hao YING, Yunjuan SUN, Yu XU, Jianchun JIANG 2023, 43 (4):  31-37.  doi: 10.3969/j.issn.0253-2417.2023.04.005 Abstract ( 142 )   HTML ( 5 )   PDF (616KB) ( 195 )   Save The oxygen gasification of pine sawdust for the production of bio-gas was conducted in a high-temperature fixed bed reactor. The impacts of gasification temperature and equivalence ratio(ER) on oxygen gasification prepared bio-gas heat value, bio-gas yield, and the volumetric fraction of each component in bio-gas were evaluated. The obtained optimal process parameters were debugged and validated in the demonstration project of biomass gasification to generate bio-gas for industrial boilers. The results showed that the gasification temperature of 850-950 ℃, the heat value of the gas raised initially then fell with the ER increase, reaching its maximum value when the ER was 0.24. Moreover, the gasification temperature exhibited a significant effect on oxygen gasification of sawdust. With the rise of gasification temperature, the gas heat value and the volumetric fraction of H2, CO, CH4 in gas increased, and the gas production rate increased initially, then decreased and reached its highest value at 900 ℃. Under the optimized conditions of gasification temperature of 900 ℃ and the ER of 0.24, the heat value of prepared gas was 13.14 MJ/m3, the gas yield was 0.98 L/g, and the volumetric fractions of H2, CO, CH4 and C2Hm in the gas were 17.64%, 39.78%, 12.45% and 2.76%, respectively. These parameters were implemented in the demonstration engineering, resulting in a calorific value of 10.90 MJ/m3 and a gas production rate of 1.02 L/g. Figures and Tables | References | Related Articles | Metrics

Select

Determination of trans-Anethole and Shikimic Acid Content in Star Anise by Near Infrared Spectroscopy Based on Partial Least Squares Method Qiang LI, Ying ZHOU, Jiaming LIU, Miaofeng LIANG 2023, 43 (4):  38-46.  doi: 10.3969/j.issn.0253-2417.2023.04.006 Abstract ( 125 )   HTML ( 1 )   PDF (1383KB) ( 190 )   Save The partial least squares(PLS) method was used to establish the near infrared quantitative analysis model for the contents of trans-anethole and shikimic acid in Illicium verum. The near-infrared spectrogram(NIR)of star anise powder was collected by near-infrared spectroscopy, and the mass fractions of trans-anethole and shikimic acid in star anise powder were determined by high performance liquid chromatography(HPLC) as reference values. The NIR was correlated with the reference values of mass fractions through spectral processing software, and the quantitative analysis model of each component to be measured was established. The spectra of trans-anethole were pretreated by the second derivative, the wave number ranges were 7 502-5 446.2 and 4 601.5-4 246.7 cm-1 and the dimension was 10; the spectra of shikimic acid were pretreated by the first derivation plus linear substraction with 7 502-6 098.1 and 5 450.1-4 597.6 cm-1 as wave number ranges, and the dimension was 8. The results showed that the determination coefficients(R2) of the established rapid nondestructive quantitative detection models for the contents of trans-anethole and shikimic acid in I. verum were 90.86% and 93.13%, respectively. The root mean square errors of cross-validation(RMSECV) of the correction set were 0.158 and 0.285, the root mean square errors of the verification set(RMSRP) were 0.068 7 and 0.171, and the paired T-test P values were 0.761 and 0.194, respectively, both greater than 0.05. The deviation between the measured value and the reference value was small. The established model could accurately determine the contents of trans-anethole and shikimic acid in I. verum. Figures and Tables | References | Related Articles | Metrics

Select

Synthesis and Antibacterial Activity of Rhein Amidoamide Derivatives Peng LIAO, Can ZHOU, Jingzi LIU, Huibin YU, Lijun ZHAO 2023, 43 (4):  47-52.  doi: 10.3969/j.issn.0253-2417.2023.04.007 Abstract ( 105 )   HTML ( 15 )   PDF (540KB) ( 203 )   Save In order to improve the physicochemical properties and antibacterial activity of rhein, its structure was modified. Using O-benzotriazole-N, N, N′, N′-tetramethylurea(HBTU) as condensing agent, and N, N-diisopropylethylamine(DIPEA) as catalyst, six target compounds (4a-4f) were synthesized by the reaction of rhein with L-proline methyl ester hydrochloride, L-tryptophan methyl ester hydrochloride, L-phenylalanine methyl ester hydrochloride and substituted benzylamine. The structures of the target compounds were confirmed and characterized by(1H, 13C, 19F) NMR and high-resolution mass spectrometry. The antibacterial activities of these compounds against Escherichia coli, Staphylococcus aureus and Proteus vulgaris were tested for the first time. The results indicated that some of the target compounds had good antibacterial activities, and the minimum inhibitory concentration(MIC) value of compound 4a against S. aureus was 0.78 mg/L, and the MIC value of compound 4e against P. vulgaris was 0.39 mg/L. Their antibacterial activities were better than that of rhein and even better than that of the control drug ampicillin. Figures and Tables | References | Related Articles | Metrics

Select

Preparation of Magnetic Molecularly Imprinted Polymers and Its Adsorption Properties for 1, 2, 3, 4, 6-Pentagalloylglucose Lihua TANG, Qinhao GUAN, Liangliang ZHANG, Man XU, Linlin YAN 2023, 43 (4):  53-59.  doi: 10.3969/j.issn.0253-2417.2023.04.008 Abstract ( 112 )   HTML ( 10 )   PDF (4157KB) ( 154 )   Save The magnetic molecularly imprinted polymers(MIPS) and magnetic non-imprinted polymers(NIPS, without PGG) were prepared by precipitation polymerization using Fe3O4 magnetic nanoparticles as carriers, 1, 2, 3, 4, 6-penta-galloyl glucose(PGG) as template molecule and acrylamide (AM) as functional monomer. Their morphology and structure were characterized, and the adsorption performance was investigated. The results of SEM, TEM, FT-IR, and XRD showed that MIPS was spherical nanoparticle with Fe3O4 as the core and SiO2 as the outer layer, with densely packed pores on the surface. The analysis of magnetic properties shows that MIPS has good paramagnetism and can be separated under applied magnetic field. The results show that the adsorption capacity of MIPS for PGG is obviously stronger than that of NIPS.The adsorption process of PGG by MIPS was fitted well with the Langmuir adsorption isotherm model, with a maximum adsorption capacity of 67.02 mg/g. The adsorption process of PGG by MIPS was very consistent with the second-order kinetic model. In the reuse performance experiment of MIPS, the adsorption capacity of the fifth cycle 53.16 mg/g, could still reach 83.78% of the first adsorption capacity. This indicated that the reuse performance of MIPS was better and could achieve specific adsorption of PGG. Figures and Tables | References | Related Articles | Metrics

Select

Optimization of Extraction Process of Flavone C-glycosides from Bamboo Leaves by Deep Eutectic Solvent-Ball Mill Method Yaqian LIU, Jin WANG, Feng TANG 2023, 43 (4):  60-66.  doi: 10.3969/j.issn.0253-2417.2023.04.009 Abstract ( 106 )   HTML ( 35 )   PDF (596KB) ( 217 )   Save Ball mill method was used to extract flavone C-glycosides from bamboo leaves using deep eutectic solvents(DESs) as extraction solvent. The contents of four flavone C-glycosides(isoorientin, orientin, isovitexin and vitexin) in bamboo leaves were determined by liquid chromatography quadrupole time-of-flight mass spectrometry(LC-Q-TOF-MS). By single factor experiments and orthogonal design, the parameters including water content, extraction time and liquid-solid ratio of DESs were investigated. The results showed that the optimized extraction process of flavone C-glycosides from bamboo leaves was as follows: DESs(composed of choline chloride and ethylene glycol) water content of 50%, extraction time of 150 s, and liquid-solid ratio of 6∶1(mL∶g). Under these conditions, the total extraction yield of four flavone C-glycosides from bamboo leaves was 1.55 mg/g, including isoorientin of 0.99 mg/g, orientin of 0.23 mg/g, vitexin of 0.04 mg/g and isovitexin of 0.29 mg/g. The extraction yield of this method was 7.6% higher than that of immersion extraction, and the time and organic solvent were saved. This optimized technology combined with LC-Q-TOF-MS detection was successfully applied to the extraction and determination of flavone C-glycosides in bamboo tea samples made from bamboo leaves. Figures and Tables | References | Related Articles | Metrics

Select

Extraction and Isolation of Chemical Constituents from Ophiorrhiza japonica Bl. and Their Antioxidant Activities Mengjuan XU, Qing BU, Hongyang CHEN, Min ZHANG, Lei WU, Linfu LIANG 2023, 43 (4):  67-73.  doi: 10.3969/j.issn.0253-2417.2023.04.010 Abstract ( 127 )   HTML ( 17 )   PDF (582KB) ( 217 )   Save The Japanese snake root(Ophiorhoza japonica Bl.) was used as the raw material, soaked in anhydrous ethanol and then extracted by organic solvents with different polarities. Based on the preliminary analysis of the antioxidant activities of different extraction parts, the chemical components of each extraction parts were isolated and purified using chromatographic separation techniques including silica gel and Sephadex LH-20 column chromatography, in order to disclose the antioxidant active substances basis of the this plant. The results showed that each extraction part of petroleum ether, ethyl acetate and chloroform from O. japonica Bl. exhibited antioxidant potencies. Among them, the chloroform extraction displayed best activities, with scavenging rates against 1, 1-diphenyl-2-picrylhydrazyl free radical(DPPH·) and 2, 2′-azinobis-3-ethylbenzthiazoline-6-sulfonic acid free radical(·ABTS+) of 86% and 89%, respectively. Subsequently, ten compounds were separated and identified as(E)-3-((9H-pyrido[3, 4-b] indol-1-yl) methyl)-2-ethylidenepentane-1, 5-diol(1, deppeaninol), 6-hydroxyharman(2), harman base(3), p-hydroxy benzaldehyde(4), scopoletin(5), 3-oxo-α-ionol(6), loliolide(7), β-sitosterol(8), 3-epi-pomolic acid(9) and 1-monoolein(10). Among them, compounds 1, 4, 6, 7, 9 and 10 were identified from the genus of Ophiorrhiza for the first time. The results of free radical scavenging assays showed that compound 2 exhibited significant antioxidant activity with the half inhibitory concentration(IC50) of DPPH· and ·ABTS+ were 0.209 and 0.212 mmol/L, respectively. Figures and Tables | References | Related Articles | Metrics

Select

Delignification by Alkaline Hydrogen Peroxide Assisted with Different Solvents Beiping ZHU, Jian JIAO, fangmin LIANG, Yongjun DENG, Guigan FANG 2023, 43 (4):  74-80.  doi: 10.3969/j.issn.0253-2417.2023.04.011 Abstract ( 134 )   HTML ( 29 )   PDF (715KB) ( 262 )   Save In order to explore the effect of delignification under different organic solvent-assisted alkaline hydrogen peroxide treatment, the composition changes of poplar mechanical pulp after lignin removal by ethanol alkaline hydrogen peroxide(EAHP) and dioxane alkaline hydrogen peroxide(DAHP) were investigated using the alkaline hydrogen peroxide system(AHP) as a reference. The chemical structure, molecular weight, and hydroxyl content of alkali lignin(AL) and alkaline hydrogen peroxide lignin(AHPL), ethanol alkaline hydrogen peroxide lignin(EAHPL) and dioxane alkaline hydrogen peroxide lignin(DAHPL) were characterized by high-performance liquid chromatography(HPLC), Fourier transforms infrared spectroscopy(FT-IR), gel-permeation chromatography(GPC), and 31P nuclear magnetic resonance(31P NMR). The results showed that the three reaction systems led to the varying degradation degrees of the material yield and the dissolution of a large number of hemicellulose. Compared with AHP and DAHP, EAHP was more conducive to preserve cellulose and dissolve more lignin, and the highest lignin removal rate reached 65%. Compared with AL, AHP, EAHPL and DAHPL possessed basically the same infrared spectral peak type, both belonging to G-S type. The minimum Mn of the prepared lignin was 4 672 g/mol with low polydispersity and low phenolic hydroxyl content, while it had higher aliphatic hydroxyl group and carboxylic acid hydroxyl group contents, with the highest contents of 14.95 and 1.25 mmol/g, respectively. Figures and Tables | References | Related Articles | Metrics

Select

Synthesis Process and Structural Characterization of Polyamine Cellulose Based Chelated Fibers Yu WANG, Jun HUANG, Huamin ZHAI, Hao REN 2023, 43 (4):  81-89.  doi: 10.3969/j.issn.0253-2417.2023.04.012 Abstract ( 96 )   HTML ( 39 )   PDF (909KB) ( 181 )   Save The epoxy-activated cellulose fibers(CPGMA) were subjected to polyamination organic synthesis in water medium and in dimethylamide(DMF) medium, respectively. The effects of reaction medium, amine concentration, reaction time, temperature, liquid ratio and initial epoxy group content on the amination reaction were investigated. The results showed that DMF as the reaction medium and the temperature of 60 ℃ were the most favorable to reaction, and there was a linear relationship between fiber weight gain and amine concentration. In DMF medium, the amination reaction reached saturation within 1 h, and the increase of reaction liquid ratio was not conducive to the amination reaction. The higher epoxy group content of CPGMA, the better amination reaction. At 600 ℃, the residual amount of CPGMA(grafting rate was 198%) was 5.1%, while the residual amount of amine-modified CPGMA-EDA was 16.8%, and the thermal stability of the fiber increased. The disappearance of the tertiary carbon peak on the 5′ epoxide group and the reduction in the intensity of the methylene carbon peaks on the 2′-quaternary carbon and 6′ epoxide groups in the solid-state 13C CP/MAS NMR spectrum confirmed the success of amination reaction. Figures and Tables | References | Related Articles | Metrics

Select

Preparation of Ru-Ni/WO3 Multifunctional Catalyst and Its Catalytic Performance for Cellulose to Ethylene Glycol Mingwei ZHANG, Xiaolong WANG, Yujing WENG, Shifang MU, Qi SUN, Yulong ZHANG 2023, 43 (4):  90-98.  doi: 10.3969/j.issn.0253-2417.2023.04.013 Abstract ( 108 )   HTML ( 12 )   PDF (2488KB) ( 207 )   Save Using commercial tungsten oxide as carrier, a series of tungsten fund metal catalysts were prepared and their catalytic properties were investigated by controlling the preparation process and activation method. Results showed that the Ru-Ni/WO3 catalyst(Ru loading 2%, Ni loading 20%), which was first impregnated with Ni and then loaded with Ru using sodium borohydride liquid-phase activation, exhibited better catalytic properties for cellulosic hydrogenolysis to ethylene glycol(EG). 86% cellulosic conversion and 63% ethylene glycol selectivity were obtained at 240 ℃ and 4 MPa H2 pressure for 4 h. Subsequently, the characterizations of XRD, SEM, Raman, and XPS also employed to investigate the mechanism of the influence of catalyst composition and structure on its catalytic performance and product distribution. The results showed that bimetallic catalyst with Ni and Ru dipped step by step, and then actived by sodium borohydride liquid-phase reduction was easier to be reduced than the catalyst with normal dipping and hydrogen thermal reduction activation, and showed higher surface area and better dispersion of metal, with more surface defects and acid sites, thus was conducive to the occurrence of cascade reaction for cellulose to ethylene glycol. Figures and Tables | References | Related Articles | Metrics

Select

Aerobic Fermentation Behavior and Bio-mechanical Pulping Performance of Rice Straw Huyi ZHOU, Kuizhong SHEN, Shanming HAN, Hongying HUANG, Enhui SUN, Guigan FANG 2023, 43 (4):  99-106.  doi: 10.3969/j.issn.0253-2417.2023.04.014 Abstract ( 93 )   HTML ( 11 )   PDF (682KB) ( 175 )   Save The high-performance fiber for pulp molding, paper and paperboard products could be obtained by aerobic fermentation coupling with mechanical dissociation from agricultural straw, which would provide a new way for the high-value utilization of straw from the field. In this study, the properties of bio-mechanical pulp of rice straw were investigated by mechanical dissociation after 30 days of stacking and fermentation with composited microbials(2 Geobacillus sp, 1 Parageobacillus sp and 4 Thermos sp). The results showed that the fermentation exhibited staged processes: 1 day of warming, 10 days of high temperature fermentation stage, and 12 days of cooling and decomposition, where the highest temperature of the fermentation reached 60.0-66.2 ℃. After 8 days of aerobic fermentation, the yield of fermented materials was 71.22%. Compared with the non-fermented fiber material, the water retention value(1.95) of the fiber after 8 days fermentation increased by 18.56%, the average fiber length(0.639 mm) increased by 2.73%, and the tensile index(8.51 N·m/g), tear index(9.2 mN·m2/g) and break resistance index(0.72 kPa·m2/g) increased by 15.15%, 9.52% and 10.77%, respectively. The mass losses of straw material in the heating and the high-temperature fermentation stage mainly caused by hemicellulose and cellulose, and the degradation of lignin was relatively low. The rapid degradation of hemicellulose and cellulose provided the main carbon source and heat for the rapid heating and high temperature of the compost pile. Considering the fermentation yield and strength properties of pulp fiber, the fermentation time of the straw should be controlled within 8 days. Figures and Tables | References | Related Articles | Metrics

Select

Optimization of Pressurized Hot Water Extraction Technology and Chemical Composition Analysis from Moso Bamboo Stalks Junhao YOU, Bao ZHANG, Hang XUN, Xi YAO, Jin WANG, Feng TANG 2023, 43 (4):  107-114.  doi: 10.3969/j.issn.0253-2417.2023.04.015 Abstract ( 120 )   HTML ( 46 )   PDF (926KB) ( 157 )   Save Taking moso bamboo stalks as raw material and the dry matter yield of moso bamboo stalks extract as the optimization index, the response surface methodology was used to optimize the process parameters of pressurized hot water extraction of compounds from bamboo stalks. The optimum extraction conditions were as follows: 4-year-old moso bamboo, extraction temperature of 165 ℃, extraction time of 30 min, solid-liquid ratio of 1∶12.5. Under these conditions, the dry matter yield was 12.44%, which was close to the predicted value(12.56%). The chemical composition of the pressurized hot water extract and the heating reflux water extract of moso bamboo stem was detected by gas chromatography-mass spectrometry(GC/MS). The results of GC/MS analysis showed that the chemical composition(content of 53.30%) of 23 kinds of pressurized hot water extracts from bamboo stems was much higher than that of 13 kinds of heated reflux water extracts(27.90%), and mainly contained active ingredients such as coniferaldehyde, vanillin, syringaldehyde, acetosyringone, 4-vinyl-2-methoxyphenol, 2, 3-dihydrobenzofuran and furfural. Figures and Tables | References | Related Articles | Metrics

Select

Progress in the Preparation and Transformation of Lignin-based Aromatic Aldehydes Geliang XIE, Xianjun ZHOU, Chengyu DONG, Wei CHEN, Lujiang XU, Zhen FANG 2023, 43 (4):  115-126.  doi: 10.3969/j.issn.0253-2417.2023.04.016 Abstract ( 164 )   HTML ( 112 )   PDF (735KB) ( 281 )   Save Aromatic aldehydes were important raw materials for the synthesis of fine chemicals such as dyes, spices, pesticides and drugs. Lignin was the second largest component in lignocellulosic biomass, and was the only renewable resource for producing aromatic compounds. Catalytic oxidation could transform lignin into highly functionalized aromatic aldehydes(e.g., p-hydroxybenzaldehyde, vanillin, syringaldehyde, etc.) under mild conditions, which was regarded as one of the effective ways to realize the resource utilization of lignin. Firstly, the structural characteristics and depolymerization mechanism of lignin were introduced, and the effects of lignin structure on the production of aromatic aldehydes were summarized and discussed. Then, recent progress in the preparation of aromatic aldehydes by oxidative depolymerization of lignin was introduced in detail from the methods of catalytic oxidative depolymerization methods(e.g., wet oxidation and alkaline nitrobenzene oxidation, catalytic oxidative depolymerization with homogeneous and heterogeneous catalysts, photocatalytic oxidation and electrocatalytic oxidation) and types of catalysts(e.g., metal salts and metal porphyrins, heteropoly acids and other homogeneous catalysts, metal oxides and perovskite oxides and other heterogeneous catalysts). Moreover, the upgrading and conversion of aromatic aldehydes into high value-added products such as 2-methoxy-4-methylphenol, aromatic nitrile, aromatic amides and new organic polymer materials were further summarized. Finally, the existing problems in the current research on lignin oxidative depolymerization were summarized, and the possible development direction in the future was proposed, which laid a foundation for lignin oxidative depolymerization and high value-added utilization. Figures and Tables | References | Related Articles | Metrics

Select

Electrode Modification Materials for Molecularly Imprinted Electrochemical Sensors Chunhui MA, Xuyang QIN, Huijuan XU, Wei LI, Sha LUO, Shouxin LIU 2023, 43 (4):  127-139.  doi: 10.3969/j.issn.0253-2417.2023.04.017 Abstract ( 138 )   HTML ( 24 )   PDF (1631KB) ( 184 )   Save Based on briefly introducing the preparation principle of molecularly imprinted polymer(MIP) and the working principle of molecularly imprinted electrochemical sensor(MIECS), the application of three kinds of electrode modification materials: carbon nanomaterials, magnetic materials, and conductive polymer materials in MIECS is reviewed. Carbon nanomaterials mainly involve graphene and its series derivatives, carbon nanotubes(CNT); magnetic materials In addition to the induction and comparison of the three electrode modification methods of coating, magnetic adsorption, and electropolymerization, it mainly introduces the methods based on traditional electrodes and Magnetic Molecularly Imprinted Polymer(MMIP) modification based on magnetron electrodes; the synthetic methods of conductive polymer materials include chemical synthesis, electrochemical polymerization and microorganism-assisted polymerization. The characteristics of electrochemical polymerization are described emphatically. Finally, the development prospects and challenges of MIECS are highlighted. Figures and Tables | References | Related Articles | Metrics

Select

Research Progress of Nanocellulose-based Ultraviolet Shielding Film Materials Dan LUO, Wenhao SU, Xuan SHU, Xiuyu LIU, Hongqi DAI, Huiyang BIAN 2023, 43 (4):  140-150.  doi: 10.3969/j.issn.0253-2417.2023.04.018 Abstract ( 138 )   HTML ( 31 )   PDF (9783KB) ( 227 )   Save Nanocellulose is a natural material with high transparency and high mechanical strength, which could be prepared into films-forming materials using different methods such as vacuum filtration and solution casting. Modification of nanocellulose or addition of UV blocking agent could effectively improve the UV shielding performance of film materials, achieving its application value in the fields of photosensitive material coating, food packaging, UV protection and so on. In this paper, the mechanism of UV blocking agents was firstly introduced, then the research progress of the modified nanocellulose, nanocellulose/inorganic oxide and nanocellulose/lignin and other composite UV shielding film materials was mainly reviewed. Finally, the opportunities and challenges in the preparation and application of nanocellulose-based UV shielding films were summarized and prospected. Figures and Tables | References | Related Articles | Metrics