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    28 October 2022, Volume 42 Issue 5 Previous Issue   
    Preparation of Cellulose Nanofiber-based Flexible Pressure Sensors via Electrospun and Its Performance
    Cuihuan LI, Sheng CHEN, Jianzhen MAO, Jiahui MU, Ziqiang SHAO, Feng XU
    2022, 42 (5):  1-7.  doi: 10.3969/j.issn.0253-2417.2022.05.001
    Abstract ( 64 )   HTML ( 23 )   PDF (6976KB) ( 63 )   Save

    Cellulose acetate nanofibers(CANFs)were prepared by electrospinning cellulose acetate(CA), followed by deacetylation to obtain cellulose nanofibers(CNFs). Subsequentially, in-situ polymerization of polypyrrole was perform to fabricate the conductive composite nanofibers(CNFs-PPy), which was combined with cellulose paper as a flexible substrate for assembling a flexible pressure sensor. The materials were characterized by FT-IR, XRD and SEM, and the mechanical and sensing performance of the devices were analyzed using a universal material testing machine and an electrochemical workstation. The results showed that polypyrrole was successfully coated on the surface of cellulose nanofibers, and the nitrogen content of composite nanofiber was 24.8%. The current-voltage curves of the sensor maintained a good linear relationship under 1-15 kPa pressure load, and the relative current change rate increased with increasing pressure. The sensitivity values of the sensor were up to 1.77 kPa-1 in the range of low pressure(0-0.99 kPa), 0.43 kPa-1 in the range of medium pressure(1.00-8.33 kPa) and 0.22 kPa-1 in high pressure(8.53-15 kPa), respectively. The sensor had excellent signal reliability and stability, i.e., the sensing signal remained stable after 3 000 cycles of loading. The sensor could realize the real-time monitoring of external pressure changes such as finger touch, which provided a new insights into the development of green electronics.

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    Catalytic Hydrogenation of Furfural to Furfuryl Alcohol Using Co3AlOx
    Wei JIANG, Ying XIN, Mingyue GONG, Weizhong WANG, Dongjun WANG, Yong SUN
    2022, 42 (5):  8-14.  doi: 10.3969/j.issn.0253-2417.2022.05.002
    Abstract ( 36 )   HTML ( 13 )   PDF (3855KB) ( 45 )   Save

    Co/Al bimetallic oxide catalyst was prepared and used for catalytic reduction of furfural to furfuryl alcohol. The effects of the active metal ratio on the physical and chemical properties of the catalyst were discussed by adjusting the molar ratio of Co/Al. N2 adsorption/desorption analysis showed that the series of prepared CoxAlOy catalysts were mesoporous materials with an average pore size of about 20 nm. NH3-TPD analysis showed that the dominance of moderate acid sites was favorable for hydrogenation of furfural to furfuryl alcohol. The prepared Co3AlOx with the Co/Al molar ratio of 3∶1 exhibited excellent catalytic activity. Under the operational conditions of 0.3 g furfuryl alcohol, 20 mL solvent 1, 4-dioxane, 0.12 g catalyst Co3AlOx, reaction time 3 h, H2 pressure 2 MPa and reaction temperature 120 ℃, the conversion of furfuryl alcohol was more than 98.95%, and the yield of furfuryl alcohol could reach 96.25%. XRD, TEM and XPS analysis showed that Co3AlOx existed in the mixed phase of CoAl2O4 and Co2O3, and the specific surface area and moderate acid strength were the key factors determining the catalytic activity. The catalytic activity of Co3AlOx catalyst could still maintain 83% after 5 cycles, which indicates its good cycle stability.

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    Preparation of Poly(Trimethylolpropane Dehydroabietate Malonate) and Its Micellar Aggregation
    Kun QI, Yanzhi ZHAO, Haitang XU, Fuhou LEI, Han LONG, Juying ZHOU
    2022, 42 (5):  15-22.  doi: 10.3969/j.issn.0253-2417.2022.05.003
    Abstract ( 28 )   HTML ( 15 )   PDF (4189KB) ( 49 )   Save

    A novel biocompatible dehydrogenated trimethylolpropane polyester(DMPE) was successfully prepared from trimethylolpropane dehydroabietate(DATE) and malonic acid(MA). The physicochemical properties of DMPE were characterized by a variety of methods and its cytotoxicity was investigated. The aggregation and de-aggregation characteristics of DMPE chains during cooling and heating process, and the kinetic parameters of DMPE micellar aggregation under constant temperature conditions were also studied. The results showed that DMPE has been successfully synthesized, and the number average molecular weight, the weight average molecular weight, and the degree of polymerization were 3 900, 6 300, and 7.8. Rayleigh scattering spectroscopy showed that DMPE had a scattering peak at 400 nm, and TG and analysis showed that DMPE started to compose at about 320 ℃, and completely degraded at 450 ℃. Moreover, DMPE aqueous solution had a proliferative effect on L929 cells at a low concentration, and the cell viability gradually decreased with the increasing concentration. During the cooling process, the DMPE chains aggregated to form micellars, and the aggregation temperature increased with the increasing concentration. However in the heating process, the aggregated micellars gradually de-aggregated and presented an obvious hysteresis. Kinetic studies indicated that the low temperature was conducive to the aggregation of micells. When the temperature was 3 ℃, the Avrami index(n) was 5.79, rate constant(kp) was 1.78×10-11, the pre-exponential factor(A) was 1.55×1022, and the apparent activation energy(Ea) was -127.12 kJ/mol. The temperature responsiveness and biocompatibility of DMPE make it as a surfactant and drug carrier.

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    Preparation and Properties of Sodium Lignosulfonate Double Network Hydrogels
    Chenglong FU, Xia MENG, Chao GAO, Zhongming LIU, Shoujuan WANG, Fangong KONG
    2022, 42 (5):  23-29.  doi: 10.3969/j.issn.0253-2417.2022.05.004
    Abstract ( 39 )   HTML ( 20 )   PDF (3913KB) ( 52 )   Save

    A kind of sodium lignosulfonate hydrogel was prepared by a simple solution blending method using sodium lignosulfonate(SL), sodium alginate(SA) and acrylic acid(AA) as precursors, where N, N'-methylenebisacrylamide(MBA) and ammonium persulfate(APS) were the cross-linking agent and initiator. This sodium lignosulfonate hydrogel was further ionically cross-linked and formed the double-network hydrogels(LSTH). Meanwhile, single-network hydrogels(LH) and acrylic hydrogels(AAH) without sodium alginate were also prepared. Then, the swelling properties, thermal stability, surface morphology, mechanical properties and strain sensing properties of the hydrogels were investigated. The results showed that when the dosage of SL was 0.2 g, the dosage of SA was 0.1 g, and the dosage of cross-linking agent was 0.02 g, the LSTH reached the highest equilibrium swelling rate of 55.31 g/g. Also, the addition of sodium lignosulfonate was beneficial to improve the thermal stability and mechanical strength of the hydrogel. When the dosage of SL was 0.2 g, the dosage of SA was 0.1 g, and the dosage of cross-linking agent was 0.05 g, the compressive strength of LSTH reached 835.53 kPa, which was 200 kPa higher than that of LH. After 90 rapid compression cycles at a high compression set of 80%, LSTH could still maintain a stable structure, good compressive strength and recoverability. The strain sensing properties showed that the hydrogel could respond quickly and be stable to external pressure and strain stimuli, indicating its good response reproducibility and stability.

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    Separation and Purification of Gastrodin by Urushiol Methacrylate Bonded SiO2 Column and Its Thermodynamic Study
    Lei ZENG, Fengmei YI, Yu CAO, Bo'an SHI, Fuhou LEI
    2022, 42 (5):  30-36.  doi: 10.3969/j.issn.0253-2417.2022.05.005
    Abstract ( 25 )   HTML ( 15 )   PDF (609KB) ( 47 )   Save

    Using phenyl-β-D-glucopyranoside(PGL) and 4-methoxyphenyl-β-D-glucopyranoside(MGL) as the competitive molecules owing to its structural analogues of gastrodin(GAS), the separation performance of GAS by usurushiol methacrylate bonded SiO2 column was investigated, and its thermodynamics behavior was also analyzed. The result showed that the optimum separation conditions of urushiol methacrylate bonded SiO2 chromatographic column were as follows: 0.05% phosphoric acid water solution(3∶97, volume ratio), flow rate 0.4 mL/min, column temperature 25 ℃, detection wavelength 220 nm and injection volume 20 L. Under this chromatographic condition, the resolution of urushiol methacrylate bonded SiO2 chromatographic column to PGL-GAS and MGL-GAS was 7.8 and 14.0, respectively. The thermodynamic studies revealed that the ΔH, ΔΔH and ΔΔG values of both PGL-GAS and MGL-GAS were negative, and the ΔΔS values were greater than zero, during the process of separation. It indicated that the separation of GAS and its structural analogues on urushiol methacrylate bonded SiO2 column was a thermodynamic spontaneous process, which was driven both by the entropy and enthalpy. The retention and resolution of analytes decrease with the increasing column temperature. After the crude extract was purified by usurushiol methacrylate bonded SiO2 column, the impurities were significatly reduced, and the purity of gastrodin increased from 17.06% to 93.45%. The urushiol methacrylate bonded SiO2 column exhibited good separation performance and stability during the separation process.

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    Preparation, Characteristics and Electrochemical Performance of Chinese Fir Bark-based Activated Carbon
    Lu LUO, Lingcong LUO, Jianping DENG, Yalan ZHOU, Mizi FAN, Weigang ZHAO
    2022, 42 (5):  37-44.  doi: 10.3969/j.issn.0253-2417.2022.05.006
    Abstract ( 31 )   HTML ( 7 )   PDF (2910KB) ( 44 )   Save

    Fir bark-based activated carbon with high surface area and porosity was prepared from by a two-step method of low-temperature carbonization and KOH high-temperature activation using forestry waste fir bark as precursor, and applied as supercapacitor electrode materials. The central composite design(CCD) and response surface analysis were carried out using alkali carbon ratio and activation temperature as the experimental factors, and the mass specific capacitance at a current density of 0.5 A/g as the response value. The results showed that the specific surface area of fir bark-based activated carbon could reach 1 522 m2/g, and the maximum pore volume could reach 0.84 cm3/g. At the same time, the average pore size was 1.12 nm, and a large number of mesopores and micropores was coexisted. The interaction between the alkali carbon ratio and the activation temperature had significant impact on the capacitance. The optimal preparation process of Chinese fir bark activated carbon was obtained by response surface methodology: alkali carbon ratio of 3, and activation temperature of 605 ℃. The specific capacitance of the carbon material under this condition was 185.7 F/g. The electrochemical performance test of the activated carbon prepared under the optimized conditions indicated that the maximum specific capacitance could reach 188 F/g at 0.5 A/g, and it had a good rate capability(85.1%).

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    Synthesis, Antifungal Activity and 3D-QSAR Study of Novel 1, 3, 4-Thiadiazole-Thiourea Compounds Containing gem-Dimethylcyclopropane Ring
    Renxuan ZOU, Wengui DUAN, Guishan LIN, Baoyu LI, Yucheng CUI
    2022, 42 (5):  45-55.  doi: 10.3969/j.issn.0253-2417.2022.05.007
    Abstract ( 37 )   HTML ( 21 )   PDF (1367KB) ( 59 )   Save

    A series of novel 1, 3, 4-thiadiazole-thiourea compounds containing gem-dimethylcyclopropane ring 8a-8t were designed and synthesized by multi-step reactions in search of novel antifungal molecules. Structures of all target compounds were characterized by FT-IR, 1H NMR, 13C NMR, ESI-MS and elemental analysis. The antifungal activities of the target compounds were preliminarily evaluated. The bioassay results revealed that, at 50 mg/L, the inhibitory rate of compound 8l(R=m-BrC6H4) against P.piricola was 79.5%, which was better than that of the positive control chlorothalonil. In order to design more effective antifungal compounds against P.piricola, analysis of the three-dimensional quantitative structure-activity relationship(3D-QSAR) was performed using the comparative molecular field analysis(CoMFA) method. The reasonable and effective 3D-QSAR model(r2=0.991, q2=0.514) was established.

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    Properties of Rosin-modified Cardanol Coatings
    Yaocang LI, Jiawei SHAO, Hongxia MA
    2022, 42 (5):  56-60.  doi: 10.3969/j.issn.0253-2417.2022.05.008
    Abstract ( 32 )   HTML ( 17 )   PDF (582KB) ( 47 )   Save

    The coatings was prepared using the modification of cardanol by rosin, and its performance was studied. The mechanism of rosin modified cardanol and effect of rosin dosage on curing rate of coating were analyzed by FT-IR. The results showed that the phenolic hydroxyl of cardanol and the carboxylic acid of rosin were esterified during the heating process, and the unsaturated rosin structure and the unsaturated side chain of cardanol were oxidized crosslinking reaction. With the increase of rosin dosage, the curing rate of cardanol was increased. When the rosin dosage(by cardanol quality) was 10%, the bio-based rosin modified cardanol coating with high gloss and good comprehensive properties could be obtained by curing at 150 ℃ after 24 h with 5% cobalt naphthenate as catalyst. Its gloss was 115, adhesion level was 1, pencil hardness was 2H, the impact strength was 35 kg/cm, and the flexibility was 1 mm.

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    Antioxidant Activities Analysis of Different Polar Solvent Extracts from Camellia fascicularis H. T. Chang
    Xuhua HE, Zhijiao SHI, Xiaowei PENG, Huan KAN, Ping ZHAO, Yun LIU
    2022, 42 (5):  61-68.  doi: 10.3969/j.issn.0253-2417.2022.05.009
    Abstract ( 36 )   HTML ( 11 )   PDF (641KB) ( 47 )   Save

    In this study, polyphenols and total flavonoids were extracted from Camellia fascicularis H. T. Chang using different polar solvents such as water, petroleum ether, chloroform, ethyl acetate, and n-butanol. The radical scavenging rate on DPPH·, ·ABTS+, and ·OH and the reducing power were used as indicators to analyze the antioxidant capacity of different polar solvents extracts from C. fascicularis. The results showed that extraction abilities for polyphenols and total flavonoids from C. fascicularis by different polar extract solvents and the antioxidant capacities of different polar extracts were different. The order of extraction abilities for polyphenols and total flavonoids were as follows: water>ethyl acetate>petroleum ether>chloroform>n-butanol and water>ethyl acetate>chloroform>petroleum ether>n-butanol, respectively. C. fascicularis showed good antioxidant activities, and there were some differences in antioxidant capacities of different polar extracts. The comprehensive antioxidant capacities of water and ethyl acetate phases were higher than that of chloroform, n-butanol, and petroleum ether phases. The water phase extract exhibited the strongest scavenging capacities for DPPH· and ·ABTS+, and the IC50 values were (38.634±2.556) and (276.610±8.416)mg/L, respectively, followed by the ethyl acetate phase((50.845±3.985) and (362.754±22.555) mg/L). The petroleum ether phase showed the strongest scavenging capacities for ·OH with an IC50 value of (180.88±49.568) mg/L, followed by the chloroform phase((1 130.630±157.932)mg/L). The water phase demonstrated the strongest total reducing power with an absorbance value of 2.281±0.103 at the mass concentration of different polar extracts of 1 750 mg/L, followed by the ethyl acetate phase(1.504±0.021).

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    Effect of the Pre-flocculation of AKD on Paper Sizing Effeciency
    Lihong ZHAO, Xun KE, Min WU, Zhiwei WANG, Liying QIAN, Junli REN
    2022, 42 (5):  69-75.  doi: 10.3969/j.issn.0253-2417.2022.05.010
    Abstract ( 32 )   HTML ( 11 )   PDF (604KB) ( 46 )   Save

    In order to obtain higher retention rate of alkyl ketene dimer(AKD) in the slurry system and improve the reaction between AKD and the cellulosic fibers, common of cationic polyacrylamides(CPAM), cationic starch(CS), and bentonite(BN), which are the common retention aids in papermaking systems were chosen to pre-flocculate AKD and thus improved its sizing efficiency. Three AKD pre-flocculation processes(E, F, G) were obtained by changing the addition sequence of the three retention aids. The effects of three pre-flocculate processes on AKD floc particle size, specific surface area, system turbidity, zeta potential, and paper sizing were investigated. The results showed that the pre-flocculation process significantly increased the size of the AKD colloidal particles. The median particle sizes of AKD flocs obtained from processes E, F, and G were 223.144, 310.461 and 263.026 μm, respectively, and the turbidity of the pulp suspension was effectively reduced. Among the three pre-flocculation processes, the pulp-E-PCC, in which the negatively charged bentonite and positively charged CS were attracted with AKD by electrostatic force, followed by the bridging effect from CPAM, generated AKD floc with a stronger binding to fibers. The adsorption of AKD by the fiber reached 2.151 mg/g at 10 min of adsorption. When AKD flocs from process E were blended with PCC for sizing and filling, the Cobb60 value of the paper sheets reduced to 20.15 g/m2, filler retention reached 90.51%, and the sizing reversal rate in 40 days decreased to 5.49%.

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    Preparation and Application of Biomass-based Carbon Aerogel as Electrodes for Supercapacitors
    Hao ZHENG, Jinghui ZHOU, Yao LI
    2022, 42 (5):  76-82.  doi: 10.3969/j.issn.0253-2417.2022.05.011
    Abstract ( 40 )   HTML ( 11 )   PDF (3369KB) ( 54 )   Save

    In order to improve the stability of biomass-based carbon aerogels, lignin(L) was modified with phosphoric acid to obtain phosphinized lignin(PL). Then, a stable covalent bond was formed with bacterial cellulose(BC) to prepare biomass-based carbon aerogels, namely bacterial cellulose/phosphinized lignin(BC/PL) carbon aerogels, which were used as electrodes for supercapacitors. The results showed that with the introduction of phosphoric acid, the thermal stability of the prepared biomass-based carbon aerogels was improved. Meanwhile, XRD analysis and Raman spectroscopy showed that its structural order was similar to the graphite structure, and the specific surface area was 310.9 m2/g, with an average pore size of 2.3 nm. The results of electrochemical performance analysis showed that the prepared modified aerogel had excellent electrochemical performance, with a specific capacity of 216.4 F/g at a current density of 1 A/g and a maximum energy density of 24.4 W·h/kg at a power density of 800 W/kg.

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    Preparation and Characterization of Waterborne Creping Adhesive
    Shuai LI, Laihui XIAO, Yigang WANG, Jie CHEN, Wenbin LI, Xiao'an NIE
    2022, 42 (5):  83-90.  doi: 10.3969/j.issn.0253-2417.2022.05.012
    Abstract ( 36 )   HTML ( 21 )   PDF (3138KB) ( 47 )   Save

    In this study, waterborne polyamide(PA236) was synthesized using adipic acid and diethylene triamine. Then, the modified PA236 was obtained by grafting waterborne epoxy resin onto PA236G. Finally, after adding a certain amount of hydroxyethyl cellulose and waterborne curing agent 906 to the PA26G, the waterborne adhesive CA514 was obtained. The structure and relative molecular weight of PA236 and PA236G were characterized by FT-IR, NMR and GPC. The results confirmed the successful synthesis of the PA236 and the grafting of waterborne epoxy. TG analysis was used to determine the thermal properties of these two products, indicating that they could be used as the raw materials for creping adhesive. The properties of the film formed by CA514 were tested. The results showed that the film formed by drying CA514 had similar properties to those of the commercial products, while it has better water resistance with an average swelling degree of 188.3%. The mechanical tests showed that the average shear strength of CA514 could reach 0.122 MPa, which was about twice as that of commercial products, and the CA514 adhesion of substrate was 136.55 N, which was about 1.4 times than that of commercial products. The result indicated that CA514 had the potential to be used as cylinder adhesive.

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    Preparation and Adsorption Properties of 10-DAB Molecular Imprinted Nanospheres
    Yijie WANG, Zheheng JIANG, Wenjia SUN, Xiaodan WU, Jingsong CAO, Yujie FU
    2022, 42 (5):  91-99.  doi: 10.3969/j.issn.0253-2417.2022.05.013
    Abstract ( 27 )   HTML ( 13 )   PDF (3894KB) ( 44 )   Save

    Molecular imprinted nanospheres(MINs) with high selective adsorption to 10-deacetyl baccatin Ⅲ(10-DAB) was prepared by 10-DAB as template molecule, and 4-vinylpyridine(4-VP) was used as functional monomer. The maximum adsorption capacity reached to 37.42 mg/g. The polymer was characterized by scanning electron microscope(SEM), Fourier transform infrared spectroscopy(FT-IR) and thermogravimetric(TG) analysis, which indicated that it was successfully synthesized. The adsorption kinetics of 10-DAB-MINs could be well described by the pseudo-second-order model, and R2 was 0.979 5. Meanwhile, the adsorption mechanism conformed to the Langmuir-Freundlich model, and R2 was 0.982 7. The cyclic adsorption results showed that 10-DAB-MINs had better recycling ability than that of the template free molecular imprinted nanaspheres(NINs). Furthermore, the adsorption capacity of 10-DAB-MINs could still reach 28.66 mg/g after recycling for 5 times, which indicated the good stability.

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    Analysis and Evaluation of Nutritional Components of Insect Tea
    Caiying BO, Xingliang CHEN, Yonghong ZHOU, Lihong HU
    2022, 42 (5):  100-106.  doi: 10.3969/j.issn.0253-2417.2022.05.014
    Abstract ( 31 )   HTML ( 15 )   PDF (520KB) ( 47 )   Save

    The content of basic nutrients, amino acids and mineral elements in 4 kinds of insect teas, including Herculia glaucinalis-Ampelopsis cantoniensis insect tea, H. glaucinalis-A. grossedentata insect tea, Hydrillodes repugnalis-Platycarya strobilacea Sieb. et Zucc insect tea and H. glaucinalis-Houttuynia cordata Thunb. insect tea, were detected and analyzed. The results showed that 4 kinds of insect teas contained a variety of nutrient compositions, but there were certain differences. The contents of polyphenol, flavonoid, total sugar, protein, crude fiber and crude fat in 4 kinds of insect teas were 17.17-255.64 μmol/g, 2.46-27.18 mg/g, 0.64%-2.52%, 0.68%-1.27%, 13.50%-18.34%, and 0.17%-9.85%, respectively. The contents of polyphenols and flavonoid were highest in the A. cantoniensis insect tea. There were 17 common amino acids in 4 kinds of insect tea, and the amino acid content was 70.16-81.46 mg/g. In particular, the contents of amino acid such as aspartic acid, glutamic acid, glycine and leucine were high. The proportion of total essential amino acids in P. strobilacea insect tea was 37.65%, which was close to the requirements of the ideal model of the Food and Agriculture Organization of the United Nations(FAO)/World Health Organization(WHO). The ratio of essential amino acids to non-essential amino acids reaches 60.39%, which meets the requirements of the ideal model of FAO and WHO. The 4 kinds of insect tea were rich in Ca, P, Mg, K and Mn and other mineral elements required by the human body. The contents of K, Mg in H. cordata insect tea were as high as 21.91 and 3.93 mg/g, respectively. In addition, A. grossedentata insect tea and H. cordata insect tea contained the essential microelement Se in human body.

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    Preparation and Properties of FeCl3/Polyacrylic Acid Transparent Conductive Wood
    Saiyu YANG, Yanan ZHANG, Tong LI, Liujun LIU, Jianxin JIANG, Jiufang DUAN
    2022, 42 (5):  107-112.  doi: 10.3969/j.issn.0253-2417.2022.05.015
    Abstract ( 39 )   HTML ( 27 )   PDF (3226KB) ( 51 )   Save

    Using Balsa wood as raw material, lignin was removed, and the acrylic acid solution was impregnation and cured to get transparent wood. Subsequently, FeCl3 solution was further impregnated to form a flexible FeCl3/polyacrylic acid transparent conductive wood. Fourier transform infrared spectroscopy(FT-IR) and scanning electron microscopy(SEM) were used to characterize these materials. The results showed that the transparent wood had the best conductivity when it was immersed in 0.75% FeCl3 solution for 60-70 min. The tensile strength of transparent wood soaked in 0.5 mol/L FeCl3 solution could reach 6.03 MPa, which was nearly 10 times higher than that of the unsoaked transparent wood(0.55 MPa). In addition, the resistance sensing performance of transparent wood was excellent, and it showed characteristic electrical changes correlated with the different human actions, which demonstrated the potential applications in conductive films, flexible human sensors and other fields.

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    Development Status and Prospect of Biomass Gasification Technology
    Xueqin LI, Peng LIU, Youqing WU, Tingzhou LEI, Shiyong WU, Sheng HUANG
    2022, 42 (5):  113-121.  doi: 10.3969/j.issn.0253-2417.2022.05.016
    Abstract ( 44 )   HTML ( 7 )   PDF (1994KB) ( 59 )   Save

    In order to promote the development of biomass gasification technology and the utilization of gasification products, the development and industrial status of biomass gasification technology, gasifier type and its development status at home and abroad were mainly introduced, and the advantages and disadvantages of biomass gasification technology were analyzed. At the same time, it is also found that China's biomass resources had great potential and biomass energy had the excellent characteristics of renewability, such as renewable, less pollution, large reserves, wide distribution, zero carbon emissions and so on. However, it was difficult to internationalize because of a series of problems such as imperfect of collection-storage-transportation system, shortage of capital chain and more by-products. It was further prospected that biomass gasification in China should not only take a basic research, but also consider the overall demand of biomass gasification technology and the competition with other technologies as the future development direction and important key point. This paper was expected to lay a solid foundation for the further development of biomass gasification technology and the high-value utilization of gasification products.

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    Recent Progress in Preparation and Application of Bio-based Hydrogels
    Shuo WANG, Yonggui WANG, Zefang XIAO, Yanjun XIE
    2022, 42 (5):  122-136.  doi: 10.3969/j.issn.0253-2417.2022.05.017
    Abstract ( 37 )   HTML ( 11 )   PDF (4081KB) ( 55 )   Save

    Firstly, this review introduced the research background and application status of bio-based hydrogels. According to the different crosslinking mechanisms, physical and chemical hydrogels were classified and described. Then, the hydrogels prepared from cellulose, chitosan, protein and other bio-based materials were summarized based on the classification of the used biomass, including the solvents system of cellulose, the preparation of cellulose-based hydrogels and modification of cellulose derivatization. Also, the feedstock sources and modification methods of chitosan-based hydrogels, as well as cross-linking mechanisms such as electrostatic interaction and imine bond formed by amine groups on their molecular chains were assembled. Protein-based hydrogels with good biocompatibility and bioactivity, formed by β-folded self-assembly of polypeptide chains were depicted as well in this review. Similarly, bio-based hydrogels prepared by using physical or chemical crosslinking of hydrophilic natural polymers such as starch, sodium alginate and carrageenan, were introduced respectively. At the same time, the main applications of functionalized bio-based hydrogels in the biomedical fields were described in detail, including drug sustained release, targeted delivery, cell media, tissue repair scaffolds, wound dressings, etc. In addition, the application and research progress of bio-based hydrogels as adsorbent materials in environmental field were reviewed, and their applications in packaging, sensing, photoelectric catalysis and other fields were also highlighted. Finally, the development opportunities and challenges of bio-based hydrogels were summarized, and the future research directions were prospected.

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    Review on Structure Modification and Pharmaceutical Formulations of Plant Ployprenol
    Hua YUAN, Hong SHEN, Yangyang YAN, Changwei ZHANG, Chengzhang WANG
    2022, 42 (5):  137-146.  doi: 10.3969/j.issn.0253-2417.2022.05.018
    Abstract ( 37 )   HTML ( 11 )   PDF (943KB) ( 48 )   Save

    Plant polyprenols were a class of natural compound of esters with good biological activity, such as anticancer, hepatoprotective and antiviral. However, the strong hydrophobic of polyprenols resulted in the low bioavailability in the human body. In view of the structural characteristics of plant polyprenols containing multiple unconjugated double bonds and terminal hydroxyl groups, the research progress of polyprenols chemical modifications, such as addition, oxidation, esterification, amination, alkylation and grignard reaction were summarized, and a series of representative polyprenols derivatives and their biological activities were introduced. Meanwhile, the latest design and development of nanoemulsions, liposomes and injections based on plant polyprenols and their derivatives were reviewed, which provide a reference for further research into the development of pharmaceutical drugs of polyprenols and their derivatives.

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