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    30 January 2017, Volume 51 Issue 1 Previous Issue    Next Issue
    Preparation and Antibacterial Activity of Wood Fiber Modified with Chitosan-Ag Nanoparticles
    FENG Xiaoyan, ZHENG Kun, CHEN Ying, WANG Chunpeng, CHU Fuxiang
    2017, 51 (1):  1-7.  doi: 10.3969/j.issn.1673-5854.2017.01.001
    Abstract ( 762 )   PDF (1584KB) ( 761 )   Save
    Chitosan-Ag nanoparticles(CS-Ag NPs) were prepared by liquid phase reducing method and then modified on the wood fiber with γ-mercaptoproyl trimethoxysilane as coupling agent to obtain the antibacterial wood fiber. The morphology of CS-Ag NPs was analyzed by TEM. The morphology and chemical structure as well as the thermal stability of the modified wood fiber were characterized by FT-IR, SEM and TG. Moreover, the water absorbency of the wood fiber was explored. The results indicated that the modified wood fiber showed high thermal stability and low water absorbency. The antibacterial effects of the wood fiber against methicillin-resistant Staphylococcus aureus(MRSA), gram-positive bacteria Staphylococcus aureus, Bacillus cereus and gram-negative bacteria Escherichia coli were studied with AGAR plate counting method. It showed that the inhibitory rates of the modified wood fiber against the bacteria were all up to 99.0%. Furthermore, the antimicrobial properties of the wood fiber board treated with PVP-Ag NPs and CS-Ag NPs were investigated. It indicated that the wood fiber board treated with CS-Ag NPs did not find bacterial plaque at 8th day while the fibers treated with PVP-Ag NPs and untreated found the plaque at 5th day in hygrothermal environment. The results illustrated that the wood fiber board treated with CS-Ag NPs possessed greater antibacterial properties.
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    Preparation of Ethyl Cellulose/Naproxen Composite Microspheres Through Emulsion-solvent Evaporation Method
    SUN Peipei, CHEN Jinwei, SHANG Shibin, WANG Dan, ZHANG Kaitao
    2017, 51 (1):  8-12.  doi: 10.3969/j.issn.1673-5854.2017.01.002
    Abstract ( 765 )   PDF (822KB) ( 642 )   Save
    Ethyl cellulose/naproxen composite microspheres with high encapsulation efficiency were prepared by O/W emulsion-solvent evaporation method with ethyl cellulose as the carrier material and naproxen as the entrapped object. Orthogonal experiment was used to optimize the preparation process. And the results indicated that the optimal conditions were the mass ratio of ethyl cellulose and naproxen 3:1, ethyl cellulose addition 2.5%, polyvinyl alcohol addition 0.8%, Tween-80 addition 0.4%. Under these conditions, the encapsulation efficiency of naproxen was 88.97%. The morphology and structure of composite microspheres were investigated by scanning electron microscope(SEM), laser granularity analyzer and Fourier transform infrared spectroscopy(FT-IR). The SEM observation showed that composite microspheres were smooth, and laser granularity analyzer demonstrated that the mean diameter of particles was 14.014μm. The FT-IR showed that the characteristic adsorption peaks of EC and naproxen all appeared in the spectrum of microsphere and there was no new peak. This indicated no new compound generated during EC coating naproxen. The experiment of drug releasing indicated that the accumulative release rate increased with the increase of pH value of dissolution medium and reached the maximum of 82.5% at pH 9. And the composite microspheres showed better sustained release of drug.
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    Effect of Nanocellulose Additives on Oxidation of Potato Starch
    LIU Quanzu, YANG Rendang, HUA Feiguo
    2017, 51 (1):  13-19.  doi: 10.3969/j.issn.1673-5854.2017.01.003
    Abstract ( 741 )   PDF (1337KB) ( 690 )   Save
    The effect of nanocrystalline cellulose(NCC) as oxidation additive on oxidation of potato starch was studied. To characterize the influence of NCC on the degree of starch oxidation, the carboxyl content and viscosity of oxidized starch were measured. And the impacts of NCC on the oxidized cross-linked potato starch structure were analyzed by FT-IR, XRD and SEM. The results showed that the optimum conditions of potato starch oxidation with sodium hypochlorite as oxidation additive were 45℃ and pH value 9. The addition of a certain amount of NCC could promote the oxidation of starch, and the degree of starch oxidation increased with the increase of active chlorine charge. Under these conditions, when the NCC addition amount was 5% and active chlorine charge was 2.25%, compared with oxidized starch without NCC addition, the content of carboxyl group of the oxidized starch increased by 10.42%.
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    Inhibition of Free Formaldehyde in Synthesis of Urea-formaldehyde Resin
    ZHAO Houkuan, WANG Peng, XIE Xingpeng, YE Zhezi, XIE Yimin
    2017, 51 (1):  20-26.  doi: 10.3969/j.issn.1673-5854.2017.01.004
    Abstract ( 1124 )   PDF (593KB) ( 1026 )   Save
    The methods of inhibiting free formaldehyde in the synthesis of urea-formaldehyde resins are investigated. The optimization of synthesis process and the effects of tannic acid and water-soluble alkali lignin as formaldehyde-reducing agents are discussed. The results show that the optimum conditions are the molar ratio of formaldehyde to urea 1.2:1, the temperature and pH value in condensation reaction 95℃ and 5.0, the dosage of melamine 2% of the total mass of urea and formaldehyde and the dosage of polyvinyl alcohol 1% of the urea mass. The content of free formaldehyde in the product obtained under the optimum conditions can be reduced to 0.18% with the viscosity of 16.2s and solid content of 52.96%. And the storage time is more than 45d. When the dosage of tannic acid is 2% of urea, the content of formaldehyde in the product can be further reduced to 0.09% with the solid content of 53.44% and viscosity of 16.9s. The content of free formaldehyde is 0.15% when the dosage of soluble alkali lignin is 5% of urea and the other characteristics are similar to the sample with addition of tannic acid.
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    Effect of Enzymatic Pretreatment on Pore Structure of Bleached Wheat Straw Fiber
    CHEN Jiajie, LI Xinping, CHEN Shuai, WANG Zhijie, CHEN Lihong
    2017, 51 (1):  27-32.  doi: 10.3969/j.issn.1673-5854.2017.01.005
    Abstract ( 747 )   PDF (603KB) ( 593 )   Save
    In order to study the effect of fiber pore structure on the mechanical dissociation energy consumption during the preparation of microfibriled cellulose(MFC), low-temperature nitrogen adsorption method was used to analyze the effect of different dosages of compound cellulase pretreatment on the pore structure of bleached wheat straw fiber. The results showed that the BET specific surface and total entrance of fiber pore all had "W" type change of decreasing, increasing, then decreasing and increasing again with the increase of dosages of enzyme. By analyzing the changes of pore structure of fiber components after screening, it was found that the pores in cell wall relatively concentrated in fiber fines. And thus the main decreasing factor of BET specific surface and total entrance was the decline of fines content during the lower dosage of enzyme. While the dosage of enzyme was higher, transformation of fiber pores was significantly intensified and the change of porosity in the fiber cell walls was consequently the main factor which influenced the fiber BET specific surface.
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    Analysis of International Situation on Biomass Energy Technology Based on DII Patent Big Data
    JIN Junbao, GU Zhiwen, MA Yina, XING Zongxu, SHI Xueli
    2017, 51 (1):  33-38.  doi: 10.3969/j.issn.1673-5854.2017.01.006
    Abstract ( 745 )   PDF (2586KB) ( 684 )   Save
    Based on Derwent Innovations Index(DII) of ISI WoK, patent analysis tools and platforms such as Thomson Data Analyzer(TDA) and Thomson Innovation(TI) etc. were used for deeply analyzing international patent of biomass energy, systematically and objectively revealing the present situation of research and development, the distribution of patent technology, research and development hotspot, as well as the competitive landscape of biomass energy technology. The results showed that the number of patents was increasing rapidly from 2005. China, American and Japan ranked the top 3 of the number of patents. However, by the comparison of average cited times of patent, the results showed that the quality of Chinese patents was poor. The patentees of top three were Guangzhou Devotion Thermal Technology Co., Sinopec Corp. and Tsinghua University. All of them came from China. The research and development hotspot of biomass energy technology were the boller, biodiesel reaction, ethanol production, gene modification and synthesis gas after 2010.
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    Adsorption and Controlled Release of Gatifloxacin by Coconut Shell Activated Carbon
    ZHANG Jiaqiang, TAN fei, XIAO Linlong, HUANG Biao
    2017, 51 (1):  39-43.  doi: 10.3969/j.issn.1673-5854.2017.01.007
    Abstract ( 791 )   PDF (483KB) ( 677 )   Save
    The adsorption and controlled release of gatifloxacin(GTFX) from aqueous solution by coconut shell activated carbon were studied. The adsorption isotherms were measured at different temperatures. The standard changes of free energy, enthalpy and entropy in adsorption processes were calculated from the Freundlich equation. And the adsorption of GTFX was in accord with Freundlich equation. The ΔH of absorption was -1.7374kJ/mol, which demonstrated that the absorption was an exothermic process, and ΔH with less than 20kJ/mol indicated that the adsorption process was mostly physical adsorption. Meanwhile, Gibbs free energy(ΔG) was determined to be less than zero. This indicated that the adsorption was a spontaneous process. The results indicated that the value of ΔS was the main driving force of adsorption. Compared with the original activated carbon, the controlled release capacity of nitrate modified sample increased and that of ammonia water modified sample decreased. The different activated carbon controlled release processes marched with Higuchi equation.
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    Progress on the Monomer Separation,Chemical Structural Modification and Biological Activity of Urushiol from Raw Lacquer
    ZHOU Hao, WANG Chengzhang, DENG Tao, CHEN Hongxia, TAO Ran
    2017, 51 (1):  44-50.  doi: 10.3969/j.issn.1673-5854.2017.01.008
    Abstract ( 985 )   PDF (784KB) ( 821 )   Save
    Urushiol possesses catechol structure with C15 or C17 alkyl side chain. They consist of different alkyl phenols with the degree of unsaturation from 0 to 3. The potent antitumor, antimicrobial and antioxidant activities of urushiol have been greatly concerned. In this paper, the research progresses on separation method of different urushiol monomer are described. And the chemical structure modification of benzene ring and alkyl side chain urushiol to obtain stable urushiol derivatives are introduced. And then, the anti-tumor, antioxidant, antibacterial, antiviral activities of urushiol monomers and their derivatives are discussed.
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    Research Progress in Heavy Metal Ions Adsorption Materials
    ZHANG Xueyan, JIN Can, LIU Guifeng, HUO Shuping, KONG Zhenwu
    2017, 51 (1):  51-58.  doi: 10.3969/j.issn.1673-5854.2017.01.009
    Abstract ( 1149 )   PDF (785KB) ( 1154 )   Save
    The research situation of heavy metal ions adsorption materials are reviewed. The materials can be divided into inorganic adsorption materials(carbon, mineral and metal oxide), polymer adsorption materials(synthetic polymer materials and natural polymer materials) and composite adsorption materials(organic/inorganic models, organic/organic models, inorganic/inorganic models). The ion selective adsorption materials including chelating adsorption materials and ion imprinting materials are introduced in detail and the biodegradable adsorption materials(cellulose, chitosan, lignin and agriculture and forestry waste) are summarized. And they are the representatives of new types of heavy metal ions adsorption materials. Additionally, the development trend of heavy metal ions adsorption materials is predicted.
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