20 January 2011, Volume 42 Issue 01
    

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    研究与开发
  • Investigation of In-vitro Degradation Properties of Poly(lactide-co-glycolide) Blended and Gradient Films
    Hong-Ze LIU;min qi ;
    . 2011, 42(01): 1-0.
    Abstract ( ) Knowledge map Save
    Poly(lactide-co-glycolide) (PLGA) 50/50 and 75/25 were applied as materials, and films were prepared by casting method. The PLGA films included PLGA 50/50 single-component films, PLGA 75/25 single-component films, blended films of two kind of PLGAs, and gradient films with non-uniform component distribution. The four types of PLGA films were immersed in pH7.4 phosphate buffered saline at 37oC. The properties of these PLGA films such as molecular weight, mass loss, water absorption, pH value, and morphology were analyzed during degradation process. The results showed that the PLGA gradient films had the stablest degradation properties.
  • Effection of preparation condition on microstructure of PLA scaffolds
    . 2011, 42(01): 2-0.
    Abstract ( ) Knowledge map Save
    Abstract: In this paper, PLA porous scaffolds were prepared with method of gas sparkle in combination with particle leaching,. We discussed the effection of concentration, foaming agent, temperature on the morphologies and microstructure of the scaffolds, investgated the connection of the each of factors. The results show that through changing the processing condition of scaffold, scaffolds own the good microstructure, mechanical properties, interconnction,porosity. .
  • Surface modification of carbon microspheres using a silane coupling agent
    ; ;
    . 2011, 42(01): 3-0.
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    Carbon microspheres (CMSs) were oxidized by a mixture of concentrated sulfuric and nitric acids. Then oxidized CMSs were modified by 3-methacryloxypropyl trimethoxysilane. The morphologies and microstructures of all samples were characterized by Fourier transformation infra-red spectrometry, field emission scanning electron microscopy, X-ray photoelectron spectroscopy and thermogravimetry. The results indicate that oxygen-containing groups and KH-570 were successfully grafted on the surface of CMSs after oxidation and silanization treatment, which resulted in a much improved dispersion of CMSs in ethanol. This lays an experimental foundation for the further functionalization of CMSs.
  • Study on Mechanism of Preventing Tendon Adhesion by CTSb Compound Membrane
    CHANG Jing;
    . 2011, 42(01): 4-0.
    Abstract ( ) Knowledge map Save
    L929 fibroblasts are cultured by blend solution of chitosan derivatives(CTSb solution). The effect of the CTSb solution on L929 fibroblasts is evaluated by methods of MTT, TEM, GE and so on. The mechanism of CTSb compound membrane preventing tendon adhesion is investigated by the study on CTSb solution on L929 fibroblasts. The results show that the growth of L929 fibroblasts is inhibited obviously after cultured by CTSb solution. Along with the concentration of the CTSb solution gets higher, the inhibitory effect becomes more evident. The cell cycle of L929 fibroblasts has been discontinued and the fibroblasts are blocked in G0-G1 period. The secretion of growth factor TGF-β1 and aFGF is also inhibited by CTSb solution. The results hint that CTSb compound membrane produces its preventing adhesion effect by inhibiting the growth of fibroblasts.
  • Preparation and performance of a novel counter electrode based on mesoporous carbon for dye-sensitized solar cells
    Guiqiang Wang
    . 2011, 42(01): 5-0.
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    Mesoporous carbon (MC) samples were prepared by using tri-block copolymer F127 as template. The characteristics of MC were studied by N2 adsorption measurement and transmission electron microscopy. The worm-like pore was observed for as-prepared MC samples. The average pore size and the specific surface area is 6.8 nm and 400 m2/g, respectively. MC counter electrodes for dye-sensitized solar cells were fabricated by using MC as the catalyst for I-/I3- couple redox reaction. The catalytic activity of MC electrode was analysized by electrochemical impedance spectroscopy. MC electrode exhibited high catalytic activity for I-/I3- couple redox reaction. The charge-transfer resistance of MC electrode is 0.8 Ωcm2. The open-circuit voltage, the short-circuit current density and overall conversion efficiency of dye-sensitized solar cells with MC counter electrode is 0.613 V, 15.5 mA/cm2 and 6.18%, respectively.
  • Research on Large-Deformation Trapezoidal Skin Structure of Morphing Wings
    . 2011, 42(01): 6-0.
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    In this paper, the development of morphing wings and skin structures were introduced first. Trapezoidal skin structures with large deformation used in morphing wing were presented so. Then, mechanics analysis theoretical model of the trapezoidal skin structures were established. Theoretical model results and finite element analysis results were compared to verify the validity of the theoretical model. This research will provide a theoretical foundation for structural design, optimization, fabrication process and related experiment.
  • EFFECT OF NI ON THE ELECTROMAGNETIC CHARACTERISTICS OF FeCoNiB SOFT MAGNETIC THIN FILMS
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    . 2011, 42(01): 7-0.
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    To develop magnetic materials with high-frequency electromagnetic characteristics, a series of FeCoB and FeCoNiB thin films were synthesized by RF magnetron sputtering. Effects of the Ni addition to FeCoB system on microstructure and electromagnetic characteristics were investigated. It is found that appropriate increment of Ni content is of advantage to the high-frequency characteristics, resulting from the B segregation on grain boundaries. The FeCoNiB films with a thickness of 200nm exhibited 4πMs of 22.12 kG, fFMR of 3.16 GHz, ρ of 276 μΩcm, and μ' is larger than 200 in the 0.5-2.9 GHz. These results show that the presented films have potential for the electromagnetic device design in the GHz frequency range.
  • Non-covalent bindin of CNTs and adsorption of methylene blue on the modified CNTs
    WANG Huan-Ying ; ;;
    . 2011, 42(01): 8-0.
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    Abstract: The non-covalent binding of carbon nanotubes (CNTs) was carried on by using amphiphilic polymer polyvinyl pyrrolidone（pvp）.The adsorption of methylene blue by the modified CNTs was discussed. The adsorption ability of the modified CNTs was studied as a function of pH, ionic strength and the addition of pvp. The comparison of adsorption dynamics and effect of temperature between modified and unmodified CNTs was also discussed. The results indicated that the highest adsorption efficiency of methylene blue on the CNTs occurred at pH 8 when pvp concentration was 12mg/L, while ionic strength had less effect on the adsorbent. The experiment data fitted well by the pseudo-second-order equation and Langmuir、Freundlich、D-R isotherm models. The addition of pvp can accelerate the dissolution and distribution of CNTs in the water and enhance the adsorption consequently.
  • Effect of nanosized CeO2 on the electrical and mechanical properties in (PEO)10LiClO4 polymer electrolyte
    Qi De-Jiang;Ru Hong-Qiang
    . 2011, 42(01): 9-0.
    Abstract ( ) Knowledge map Save
    Using nanosized rare earth oxide CeO2 as filler and acetonitrile as organic solvent, the novel solid-state composite polymer electrolyte (CPE) films (PEO)10LiClO4-x wt.%CeO2 (x=0,2,6,9,12,15) was prepared by solution-casting technique. The AC impedance spectra show that the ionic conductivity of CPE can be improved obviously by adding appropriate nanosized CeO2, in order that CeO2 nano-particles can effectively inhibit the PEO from crystallizing and expand the amorphous region required for the lithium-ion transport. The highest ionic conductivity of 1.71×10-5S?cm-1 is achieved at room temperature with the CeO2 content of 9 wt.%, but too many CeO2 particles will obstacle Lithium-ion transfer. XRD observations confirm this conclusion. Meanwhile, CeO2 nano-particles can well disperse and transmit of extra-force, the tensile strength (TS) of CPEs are greatly improved. The TS can be achieved 2.07MPa with the CeO2 content of 15 wt.%, 4.45 times than pure (PEO)10LiClO4 system.
  • Study on Preparation and Performance of the CS/HA rods for Bone Internal Fixation
    ; ;;;;
    . 2011, 42(01): 10-0.
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    The CS/HA composites with a high performance were prepared via in situ precipitation. In this method, the calcium and phosphorus precursors were added into the solution of chitosan firstly, dispersed homogeneously. The pre-precipitated CS membrane controlled the process of CS precipitation and transformation of HA from the precursors. The results of burn-out tests indicated that the inorganic component was dispersed uniformly in chitosan matrix. FTIR, XRD and TEM were carried out to determine the components and morphology of CS/HA. The results showed that the inorganic component was exactly nano-sized HA. The mechanical properties of CS/HA were evaluated by the three point bending test. The bending strength and modulus of CS/HA (mass ratio 20/4) were 133MPa and 6.8GPa.
  • Preparation and Thermoresponse of Dual Responsive Hydrogels with Photo and Temperature response
    zhao yi ping;;;;;
    . 2011, 42(01): 11-0.
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    A dual responsive hydrogels of poly(N-isopropylacrylamide-co-acrylamido azobenzene) (P(NIPAAm-co-AAAB)) was prepared via a free-radical copolymerization route with N-isopropylacrylamide (NIPAAm) and acrylamido azobenzene (AAAB) which contains of azobenzene groups, and the thermoresponse behaviors were studied. The results disclosed that the P(NIPAAm-co-AAAB) hydrogels has temperature-sensitivity, and the thermoresponsive behaviors was reversible and affected by the molar ratio of AAAB to NIPAAm. With the increase of the molar ratio, the LCST of the dual responsive hydrogels decreased. Compared with PNIPAAm hydrogels, the swelling ratio of the P(NIPAAm-co-AAAB) hydrogel decreased, and with the molar ratio increased, the swelling ratio and deswelling speed decreased too.
  • Preparation of Elastic Aerogels at Ambient Pressure
    . 2011, 42(01): 12-0.
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    Abstract: Translucent and monolithic aerogels have been prepared by a two step (acid-base) sol-gel process with Methyltrimethoxysilane (MTMS), water , acetic acid and ammonia as the precursor, solvent, acid and base accelerators, respectively. The aerogels were dried at ambient pressure after surface modification using hexamethyldisilazane (HMDS) as the modification agent. The aerogels are very flexible, and showed excellent hydrophobic properties (the contact angle is 158°) and good thermal insulation properties ( the thermal conductivity is 0.031 W/mK). Scan electron microscope, pore size distribution analyzer, mechanical analyzer and hotdisk thermal analyzer were used to characterize the morphology, pore structure, mechanical and thermal properties of the aerogels.
  • Fabrication and wettability studies of ZnO nano material modified paint coating
    Zhou YANG ;;;;;;
    . 2011, 42(01): 13-0.
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    Dandelion-like ZnO powders were prepared by water bath deposition. The ZnO powders were then mixed with commercial anti-rust paint to form the modified paint coating. The surface structures of the coating were characterized by field emission scan electron microscope (FE-SEM), and their wettability was investigated by contact angle meter. Results show that the wettability of the coatings were enhanced after mixed with ZnO powders. The contact angle of a water droplet on the paint coating increased from 95°(before mixed with ZnO powders) to 148°(mixed with ZnO powders), and the water repellence properties of the coatings were enhanced. The effect of the ZnO powder addition on the wettability of the coating was also investigated.
  • Synthesis and research on the nicotine isoflavones derivatives
    . 2011, 42(01): 14-0.
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    Nicotine isoflavones 2a, 2b were synthesized and characterized by IR, 1H NMR, MS and elemental analysis. The effect of different solvents and concentrations on their fluorescence spectra were studied. The results show that the fluorescence intensities of these nicotine isoflavones are the strongest in cyclohexane, and the concentrations of solutions have significant effect on the intensity. The study on the antibacterial activity of these two compounds against escherichia coli and staphylococcus aureus indicates that the inhibitions are useful, especially against staphylococcus aureus.
  • Research on the determination of the single gas concentration by ZnO nanowire based gas sensors
    . 2011, 42(01): 15-0.
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    Abstract: The gas sensitivity of different matels doped ZnO nanowires to different concentration of H2 and CO was measured at 350℃.The results showed that the highest gas sensitivity of Ni doped ZnO nanowire to CO was 45.158 at its concentration of 3.92×10-3, and the highest gas sensitivity of Ag doped ZnO nanowires to H2 was 28.549 at its concentration of 2.52×10-3. In addition, linear fitting was applied on the basis of gas sensitivity curve by Origin software, by which the unkown concentration of H2 was determinated effectively. In the end, the reason of the improvement of gas sensitivity of ZnO nanowires by metal dopant was disccussed. It was believed that the chemical state of the metal was the essential reason to enhance the gas sensitivity of ZnO nanowires.
  • Preparation of nanocrystalline CdS by solvothermal process in the presence of ethylenediamine and its photocatalytic performance
    yuexiang li
    . 2011, 42(01): 16-0.
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    Nano-cadmium sulfide photocatalysts were synthesized by a solvothermal process in ethanol. Ethylenediamine(EDA) , cadmium sulfate and thioacetamide were used as a complexing agent, cadmium source and sulfur source, respectively. The effects of amount of the complexing agent, the reaction temperature and the amount of deposited platinum (Pt) on the photocatalytic activity of the as-prepared cadmium sulfide were investigated through a probe reaction, namely photocatalytic hydrogen production from formic acid solution under visible light irradiation. The samples were characterized by X-ray powder diffraction (XRD), BET, Scanning Electron Microscopy (SEM) and ultraviolet-visible absorption spectra techniques (UV-Vis). The results showed that when the molar ratio of EDA to Cd2+ was 1.5:1.0, the reaction temperature was 150℃ and Pt-loaded content was 0.15wt%, the photocatalyst exhibited the highest activity for hydrogen evolution.
  • Preparation and Electrochemical Capacitance Performance of Polyaniline Doped with Transition Metal Salt
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    . 2011, 42(01): 17-0.
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    Polyaniline doped with hydrochloric acid was synthesized by chemical polymerization, then de-doped and immersed in acetone solutions containing ZnCl2 and FeCl3, respectively. Polyaniline doped with ZnCl2 (PZn) and polyanline doped with FeCl3 (PFe) were prepared. The physic-chemical properties of polyaniline were characterized by d. c. conductivity measurement, SEM and FTIR. Using 1 mol?L-1 H2SO4 as electrolyte, the two-electrode supercapacitors were assembled. Compared with PFe, PZn has higher d. c. conductivity of 1.16×10-2 S?cm-1. PZn supercapacitors show a larger capacitance than PFe supercapacitors, a specific capacitance of 340 F?g-1 obtained. PZn supercapacitors exhibit lower inter resistance and longer cyclic life. All results suggest that PZn is a prospect material for supercapacitor.
  • Nanostructured ITO film fabricated by femtosecond laser ablation
    Zhou MingMing Zong Huang ;;
    . 2011, 42(01): 18-0.
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    An ITO film with large area surface nano-structure is prepared by femtosecond laser ablating a double-layer of ITO and ZnO films with the femtosecond laser frequency of 1KHz, pulse width of 130fs, wavelength of 775nm and energy of 20μJ. ITO film and ZnO film are obtained by magnetron sputtering and ZnO film is on the top as a buffer layer. Nano-structure is a period parallel stripes structure with a period of 176nm. Through the researching of the results induced by femtosecond laser with different energy, the relationship between the formed structure and laser energy is studying. It founded that the large area surface nano-structure is induced at the condition of laser energy less than the materials ablation threshold energy and the interference between the incident laser and the reflected second harmonic of laser is generated.
  • Influence of Carbon Target Current on Friction Coefficient of CrCN Coating
    . 2011, 42(01): 19-0.
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    The influence of Carbon Target Current on Friction Coefficient of CrCN Coating was studied through preparation of coatings deposited on single crystal silicon and M2 high speed steel(HSS) substrate using closed-field unbalanced magnetron sputtering ion plating technique. The existing form of carbon and the the influence regularity of carbon content on the organization structure of CrCN coating were analysised by EDS, AFM, XRD and XPS. The results show that the friction coefficient of coating decreases from 0.75 to 0.3, the carbon content of coating increases too with the increasing of carbon target current from 0A to 1.5A, as the same time the diameter of crystal grain becomes smaller and the roughness of the coatings becomes smaller too, the roughness of coating when IC=1.5A is 7.4% of which when IC=0A. The analysis of XPS shows that the carbon exists as the forms of C-C, C-Cr, C-O, and in which the free carbon existed as form of C-C can play the role of solid lubrication and can significantly reduce the friction coefficient of coating.
  • Microwave dielectric properties of (Pb0.5Ca0.5)(Fe0.5Nb0.5)O3 ceramics substituted by Zr for B-site
    ;;
    . 2011, 42(01): 20-0.
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    Microwave dielectric properties of B-site substitution by Zr4+ in (Pb0.5Ca0.5)[(Fe0.5Nb0.5)1-yZry]O3 (PCFNZ) ceramics were investigated. All specimens that were substituted by Zr4+ were well sintered and single orthorhombic perovskite phase. Qf values and grain sizes of PCFNZ ceramics decreased with the increase of Zr4+ content. The dielectric constant εr increased with the increase of Zr4+ content because of larger ionic polarizability of Zr4+ ion (αZr=3.25 ?) than that of (Fe,Nb)4+ ions (αB-site=3.13 ?). With the increase of Zr4+ content, the TCF firstly kept almost unchanged, and then drastically decreased from positive to negative. Typically, when Zr4+ content was at y=0.08, the excellent microwave dielectric properties of Qf=4938 GHz, εr=111 with TCF=9.06 ppm/℃ were obtained.
  • Microwave synthesis and magnetic properties of Co1-xNix/MWCNTs nanocomposites
    Huaqiang Wu
    . 2011, 42(01): 21-0.
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    Abstract: Co1-xNix/MWCNTs (x=0.2、0.5、0.6、0.8) nanocomposites with controllable composition were fabricated using microwave synthesis method. The samples were characterized by XRD, TEM, SAED, EDX spectroscopy and VSM. The results show that Co1-xNix alloy nanoparticles attached on MWCNTs are dispersed uniformly. when x=0.2、0.5、0.6、0.8, Co1-xNix alloy are all fcc structure. The magnetic properties of Co1-xNix/MWCNTs nanocomposites vary with alloy composition. Both Hc and Ms increase firstly and then decrease with increasing Co content. When x=0.5, Co1-xNix /MWCNTs nanocomposites own the optimal magnetic property.
  • Influence of Impregnation Densification on the Thermal Radiation Property of Carbon/Carbon Composites
    cao wei wei;
    . 2011, 42(01): 22-0.
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    The normal spectral emissivity and normal total emissivity of carbon composites were measured, and the surface morphology of samples were characterized by scanning electron microscope (SEM), the change relation between normal spectral emissivity and normal total emissivity of carbon composites and impregnation densification process and surface morphology was investigated. The results show that with impregnation densification , the normal spectral emissivity and total emissivity of carbon composites increased finally, the difference of total emissivity between two samples gradually reduced, the increase of resin carbon content was favorable to improve emissivity.
  • Preparation of copper nanoparticles with liquid reduction method by sodium hypophosphite
    WEN Jin ;
    . 2011, 42(01): 23-0.
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    Copper nanoparticles were prepared by two-step reduction method. Oleic acid was used as extractant and surfactant, and glucose and sodium hypophosphite were used as reductants in different reductive step. Reaction of sulfate pentahydrate with these reductants in solution at 60℃ gives cuprous oxide and copper nanoparticles, respectively. The products have been characterized by X-ray diffraction, SEM and TEM observation. The results show that the copper nanoparticles have good dispersity and stability with the protection by the dispersants.
  • Synthesis of Fe3O4 nanoparticles with various sizes and magnetic properties by coprecipitation
    Bo Dai;
    . 2011, 42(01): 24-0.
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    Nanoparticles of Fe3O4 with various sizes were synthesized from FeCl3?6H2O, FeCl2?4H2O and NaOH without use of surfactant by coprecipitation process. The phase structures, morphology, particle size and magnetic property of the products were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM) and vibrating sample magnetometer(VSM). It was found that the molar ratio of ferrous to ferric played an important role in the formation Fe3O4 nanoparticles. The mean diameter and magnetic property of Fe3O4 nanoparticles could be controlled by adjusting this ratio. The mean diameter of Fe3O4 nanoparticles swelled from ～10 to ～20 nm with the molar ratio of ferrous to ferric ferrous ions from 1:2 to 6:1. The saturation magnetization and the coercivity also increased correspondingly.
  • The absorbing properties and optimization of the Ba（Zn0.65Co0.35）2Fe16O27 powders/M-glass fibers/epoxy composite panels
    Zhenghou Zhu
    . 2011, 42(01): 25-0.
    Abstract ( ) Knowledge map Save
    Abstract: After the preparation of the ferrite Ba（Zn0.65Co0.35）2Fe16O27 powders by chemical co-precipitation and high temperature flux techniques., then we make up the ferrite powders/M-glass fibers/epoxy composite panels by manual technology. And then we use waveguide method to test the properties of the panels. The research shows than when the content of Ba（Zn0.65Co0.35）2Fe16O27 powders is constant, the absorbing properties of the composite panels increased with the adding of the thickness of the panels. The electromagnetic matching performance between the composite panels and the air may be improved when the M-glass fiber reinforced epoxy composite panels are set in front of the ferrite powders/M-glass fiber reinforced epoxy composite panels to form the multi- layer composite structure，and then can improve the absorbing properties of the composite panels.
  • Research and Improvement on Preparation Technique of IPMC Artificial Muscle
    ; ;;
    . 2011, 42(01): 26-0.
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    This thesis studies the film forming process of Nafion 117 and preparation of Ionic polymer-metal composites. Preparation of the different thickness film, on this basis use chemical deposit to prepare Ionic polymer-metal composites. The preparation mainly consists of the pretreatment of prophase, main chemical plating reaction and secondary chemical plating reaction. Because it produces bubble on the surface during the process of preparation, it needs to be stirred at high speed, we must consider the overflow of the bubble as well as make the film not to contact with the stir bar to come about any surface scratch, so we fix the film in vertical type. Make use of the performance test platform of Ionic polymer-metal composites to test dynamic characteristic and physical parameter of the sample. We have found out the relation between the thickness of IPMC and its dynamic characteristic, prepared the sample of Ionic polymer-metal composites successfully, researched the application in the air of IPMC, improved the faction database information of this material, provide basis for application of this intellectual material.
  • Influences of strain rates on the superplastic deformation behavior in (Zr72Cu16.5Ni11.5)90Al10 bulk amorphous alloy
    Ping Jun Tao
    . 2011, 42(01): 27-0.
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    Through careful regulation of alloy composition and optimization of preparation processes, a (Zr72Cu16.5Ni11.5)90Al10 bulk amorphous alloy (BAA) with superplasticity at room temperature was prepared. The influence of strain rates on the superplastic deformation behavior of the BAA was systematically studied with strain rates ranging from 4.2×10-4s-1 to 6.0×10-5s-1 under uniaxial compression at roomm temperature. The results showed that after severe deformation with an engineering strain up to 85.5%, i.e., the true strain is larger than 193%, all BAA specimens haven’t fractured, indicating the superplasticity of the BAA. With decreasing strain rates, the compressive strength, elastic modulus, plastic strain, stress peak interval and shear band sliding interval increase, while the elastic strain reduces. The density of the shear bands in the deformed side surfaces decreases with increasing strain rates. During the plastic flow, the obvious apparent strain-hardening can be found in the engineering stress-strain curves, while the real stress-strain curves exhibit significant strain-softening characteristics. After superplastic deformation, the propagation and distribution of shear bands in the side surfaces of the deformed specimen present different morphological characteristics, most of which have deviated from their idea positions.
    • 综述
  • Prepare oxide nanofibers via electrospinning and its gas-sensing performance
    . 2011, 42(01): 28-0.
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    Electrospinning technique is considered as a simple and potential method for synthesizing nanofibers with various materials, which has been applied to many fields. In this manuscript, the electrospinning technique and factors which affect the quality and the morphology of namofibers were summarized. The synthesis of semiconductor oxide nanofibers by electrospinning and their applications in gas sensor field were described. Gas sensing properties of some materials of nanofibers and nanowires or nanotubes were compared. The mechanism of excellent performance of gas sensiors made of nanofibers is analyzed.
    • 研究与开发
  • Preparation and Characterization of Magnetic -Activated Carbon from Phenolic Aldehyde
    . 2011, 42(01): 29-0.
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    Magnetic activated carbons (MAC) were prepared from phenolic resin in the presence of ferrocene. Pore structures, adsorption capacity and magnetic properties of activated carbons were characterized by gas adsorption, liquid absorption and vibration magnetometer instrument. In addition, primary process parameters in magnetic activated carbon preparation, such as amount of ferrocene and activation time, were studied and optimized. Results show that ferrocene plays roles during the preparation of MAC in two respects, one is catalytic effect to regulate the pore distribution, and the other is magnetization agent to magnetize the resulted activated carbon. When 6% ferrocene is introduced into the raw material, the derived MAC behaves high adsorption and magnetic performances, i.e. iodine value is 1022.03mg/g, methylene blue value is 99.8mg/g and the saturation magnetization of MAC reaches up to 24.85emu/g, which is 24.9 times by the common activated carbon.
  • Preparation of micro-arc oxidation coating on TC11 titanium alloy and study on its microstructure and performance
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    . 2011, 42(01): 30-0.
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    The micro-arc oxidation (MAO) coatings were prepared on TC11 titanium alloy in the Na2SiO3-Na2WO4-NaOH electrolytes. The micro-structure, thickness and phase component of MAO coatings were analyzed by means of scanning electron microscopy(SEM),X-ray energy dispersive spectrum (EDS) and X-ray diffraction (XRD).The physical chemistry properties were studied by HVS-1000 micro Vicker, MFT-4000 Scratch Tester and electrochemical method. The results show that MAO coating is composed of the two layer structure with surface loose zone and compact zone, and its average thickness is 135μm.The main phases are TiO2,γ-Al2O3,Al2TiO5 and amorphous SiO2,the key elements of MAO coatings take on a gradient distribution. The maximum micro-hardness is about 4.7 times as that of the substrate, and bonding force between MAO coating and substrate is more than 48.50N.Compared with the substrate, the MAO coating has better corrosion resistance in 4.5% NaCl water solution, whose corrosion current density decreases 3 orders of magnitude, and corrosion potential increases 599 mV in positive direction.
  • Enzymatic synthesis of PLA-PEG-PLA tri-block copolymer under single-mode focus microwave radiation
    LUO Bing-Hong ;;
    . 2011, 42(01): 31-0.
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    PLA-PEG-PLA tri-block copolymer was synthesized by precision microwave organic synthesis system which combining single-mode focusing microwave radiation technology and synchronized pneumatic gas cooling technology. In the experiment, porcine pancreatic lipase(PPL) or tin octoate(Sn(Oct)2) as a catalyst respectively, and poly(ethylene glycol) as a co-initiator to initiate the bulk ring-opening polymerization of D,L-LA. In order to find the best reaction conditions, the influences of macrowave power, the type and content of catalyst, irradiation time and reaction temperature on the yield of copolymers were analyzed by orthogonal test. Furthermore, PLA-PEG-PLA tri-block copolymers with different composition were perpared by changing the nD,L-LA/nPEG feed ratio. The structure and properties of the tri-block copolymer were studied by IR, 1H NMR, GPC and surface contact angle measurements. Results showed that PLA-PEG-PLA tri-block copolymer was both successly obtained using the two catalysts under single-mode focus microwave irridation, but the catalyst sufficiency of the PPL was low than that of the Sn(Oct)2. The nD,L-LA/nPEG feed ratio had a strong influence on the structure and properties of tri-block copolymer, higher nD,L-LA/nPEG feed ratio led to copolymer with higher molecular weight. Compared to pure PLA, the copolymers show higher hydrophilicity due to the incorporation of hydrophilic PEG units in the copolymers.
  • Investigation on Oxygen Chemical Diffusion Coefficient and Electrical Properties of (Pr1-xNdx) 0.6Sr0.4Co0.8Fe0.2O3-δSystem with Two Rare Earths for Cathodes
    . 2011, 42(01): 32-0.
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    Perovskite oxides of (Pr1-xNdx) 0.6Sr0.4Co0.8Fe0.2O3-δ(x= 0.2,0.4,0.6,0.8) samples were obtained by solid state-reaction method. Its phase structures and chemistry state were analysed by X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS). The oxygen chemical diffusion coefficient of (Pr1-xNdx) 0.6Sr0.4Co0.8Fe0.2O3-δ was determined by electrical conductivity relaxation technique. The resultes show that the conductivity of (Pr1-xNdx) 0.6Sr0.4Co0.8Fe0.2O3-δ increases with increasing of oxygen partial pressure. The (Pr1-xNdx) 0.6Sr0.4Co0.8Fe0.2O3-δ samples have higher oxygen chemical diffusion coefficient, which increase with the increasing of temperature and increasing of content Nd. The oxygen chemical diffusion coefficient was highest at x=0.8, which achieved 6.75× 10-5cm2?s-1 at 800℃. The max conductivity of the specimen of (Pr0.2Nd0.8) 0.6Sr0.4Co0.8Fe0.2O3-δis 1318.138S.cm-1 at 600℃, 1.0×105Pa oxygen partial pressure, is comparatively potential cathodes material for intermediate temperature solid oxide fuel cells
  • Hydrophilicity and Cell Compatibility Studies on β-cyclodextrin Modified Poly(d,l-lactic acid)
    ZHU Jiu-jin
    . 2011, 42(01): 33-0.
    Abstract ( ) Knowledge map Save
    A novel cyclodextrin polymer (PLA-β-CD) was synthesized by N-acylation reaction of MPLA (maleic anhydride modified poly(d,l-lactic acid)) using hydrophilic mono(6-(2- aminoethyl)-amino-6-deoxy)-β-cyclodextrin(β-CD-6-E) as acylating agent. Surface wettability and cell biocompatibility of PLA-β-CD were investigated. The tests indicated that the static water contact angle of PLA-β-CD was decreased from 76.7o to 72.1o comparing with PLA, while the water absorption ratio was increased from 18.3% to 23.9%. The morphology of osteoblasts on PLA-β-CD film was observed by invert light microscope and it revealed that the osteoblasts cultured on PLA-β-CD spread was wider than PLA while the cell density on the former was higher than the latter. Cell proliferation was determined by MTT assay at 2, 4, 6, 8d, and the results showed that proliferation power of osteoblasts cultured on PLA-β-CD stronger than PLA.
  • Preparation and Characterization of Nanocrystalline La203 by the Method of Reverse Microemulsion
    FENG Fa-mei ;Xie Jia Qing he xi yang ;wang ying ;xie bin
    . 2011, 42(01): 34-0.
    Abstract ( ) Knowledge map Save
    Well-dispersed La2O3 nanoparticles were successfully prepared in a simple system composed of AEO(3)-hexanaphthene-ammonia (W/O) microemulsion in this paper. The morphology and microstructure of the products were characterized by the laser particle size analyzer, Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometer(XRD), differential scanning calorimeter (DSC) and transmission electron microscope(TEM). It was found that the La2O3 nanoparticles obtained from this method have well-proportioned size distributions; the surfactant (AEO-3) molecule was adsorbed on the surface of La2O3 nanoparticles precursor, which is favorable for the dispersion of La2O3 nanoparticles; the La2O3 nanoparticles calcined was a crystal of the hexagonal structure.
  • Friction and Wear Characteristics of Fe-based Bulk Metallic Glasses
    . 2011, 42(01): 35-0.
    Abstract ( ) Knowledge map Save
    The amorphous alloy rods with a diameter of 5mm of Fe41Co7Cr15Mo14C15B6Y2 were prepared by copper mold with sucking casting method. The characteristics of dry wear behavior for Fe-based bulk metallic glasses and GCr15 steel were investigated using pin-tray equipment at the ambient temperature in this paper. Worn surface morphologies of the samples were observed on a scanning electron microscope. Friction and wear characteristics of the Fe-based bulk metallic were studied and compared with GCr15 steel. Result indicated that the Fe-based bulk amorphous alloy shows well wear-resistance. With the wear distance extended, Fe-based bulk amorphous alloy shows different abrasive mechanism on the 30N load. The friction coefficient of the Fe-based bulk metallic glasses and GCr15 steel are both between 0.5 and 0.8. The two kinds of materials have the similar wear-resistance.
  • The in vitro study of lactosylated chitosan based self-assembled nanoparticles as a drug carrier system
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    . 2011, 42(01): 36-0.
    Abstract ( ) Knowledge map Save
    This study is to prepare lactosylated chitosan-based nanoparticles used as the carrier for the anticancer drug: methotrexate (MTX) and to provide the reference data for the study of liver-targeting drug carrier systems. Firstly, N-lactosyl-chitosan conjugate (CLCS) was synthesized and characterized by FTIR and 1H-NMR. Secondly, CLCS nanoparticles were prepared by the self-assemble method, and their size and morphological characteristics were analyzed by dynamic laser light scattering and transmission electron microscopy. Thirdly, MTX was loaded into CLCS self-assembled nanoparticles using microdialysis method; MTX loading efficiency and loading content were determined by UV method; MTX release properties from CLCS self-assembled nanoparticles were valued by the dynamic dialysis method.
  • Preparation and characterization of La0.9Sr0.1Ga0.8Mg0.2O3-δ thin film deposited by RF magnetron sputtering
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    . 2011, 42(01): 37-0.
    Abstract ( ) Knowledge map Save
    A dense and crack-free La0.9Sr0.1Ga0.8Mg0.2O3-δthin film has been prepared by RF magnetron sputtering method on porous LSCM7355 anode substrates. The film with the good apparent morphology and a thickness about 10μm was obtained when the operating parameters fixed as follows: the sputtering power is 210W，the temperature of substrates is 300℃,the sputtering pressure is 5Pa and the sputtering time span is 12h.The polycrystalline perovskite type structure was obtained after the film annealed at 1000℃ for 2h in air.
  • Preparation and structure characterization of temperature-sensitive poly(vinylidene fluoride) hollow fiber membrane
    Shen Xiang ;
    . 2011, 42(01): 38-0.
    Abstract ( ) Knowledge map Save
    A poly(vinylidene fluoride)–graft-poly(N-isopropylacrylamide) (PVDF-g-PNIPAAm) copolymer was synthesized, and from which a novel temperature-sensitive copolymer hollow fiber membrane was prepared based on the technique of dry-wet spinning. The structures of the hollow fiber membrane were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray Diffraction (XRD), Differential scanning calorimetry (DSC), Scanning electron microscope (SEM), respectively. The results showed that the PVDF-g-PNIPAAm hollow fiber membrane possessed the same microcrystalline structure as the PVDF membrane, while the degree of crystallinity of PVDF-g-PNIPAAm hollow fiber membrane decreased remarkably, which resulted in the lower melting temperature. Larger finger-like structures were formed in the cross-sections of PVDF-g-PNIPAAm fiber membrane with a higher porosity for the improvement of hydrophilicity.
  • Preparation and characterization of PZT fibers by VSSP method
    Jiang Wen bo
    . 2011, 42(01): 39-0.
    Abstract ( ) Knowledge map Save
    Long PZT fibers with diameter of 250 μm have been prepared by VSSP (viscous suspension spinning process) method using cellulose and PZT particles as raw materials. Green fibers and sintered fibers were characterized by SEM and XRD. The effects of factors such as the content of dispersant, weight ratio of PZT particles to cellulose and ageing time on the uniformity of the PZT fibers were studied. The optimal preparation conditions obtained by orthogonal testing and further experiments are as follows: content of dispersant 0.4 g/kg; weight ratio of PZT particles to cellulose 25:1; ageing time 2.5 h. Under the optimal conditions, the uniformity of fibers was 87.50 %. Sintered at above 1280 oC, the porosity of fiber is 4 %. It has a perovskite phase structure and posses a mixture of rhombohedral and tetragonal phases.
  • Preparation of nanocrystalline of NiO by ultrasonic chemical precipitation method
    Zhang Le Guan
    . 2011, 42(01): 40-0.
    Abstract ( ) Knowledge map Save
    Nano-NiO powder was prepared with Ni(NO3)2?6H2O and (NH4)2C2O4?H2O as raw materials by ultrasonic chemical precipitation method.Composition and morphology of precursor and product were characterized with XRD,FTIR and TEM. Experiment results showed that the precursor of nickel oxalate dehydrate was obtained via ultrasonic chemical precipitation method. Compared with bulk-NiO, Ni-O stretching vibration absorption and acromion peaks of the Nano-NiO products in FTIR pattern give rise to red-shift. The NiO nanoparticles were spherical in shape, smooth edges, weak agglomeration and homogeneous particle size (average about 70 nm)
  • Preparation of La0.4Sr0.6TiO3 films on seed layers/Ni-5%W with metal-organic deposition method
    . 2011, 42(01): 41-0.
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    In this paper, SrTiO3 seed layers were prepared on the biaxially textured Ni-5at.%W alloy substrates with metal-organic deposition method(MOD). Then La0.4Sr0.6TiO3 films were deposited on the seed layers. The SEM morphology showed the seed layers’ grains distributed uniformly, size was consistently. The effects of different heat treatment temperature on the orientation and morphology of films were studied by XRD and SEM. The results showed that well-oriented, smooth, dense, crack-free and pinhole-free La0.4Sr0.6TiO3 films could be deposited on Ni-5at.%W alloy substrates under Ar-4% H2 atmosphere and at 950℃.
  • The effect of surface chemical state of supports on structure and electrocatalytic activity of Pt/C electrocatalysts
    yang xi kun
    . 2011, 42(01): 42-0.
    Abstract ( ) Knowledge map Save
    A series of carbon black supports with different surface chemical state were prepared with the oxidation treatment of Vulcan XC-72 carbon black. Pt/C catalysts were fabricated with formaldehyde as the reducing agent and hydrochloroplatinic acid as the precursor. The chemical composition, chemical state, crystal structure and surface morphology of carbon black supports and Pt/C catalysts were respectively studied by x-ray photoelectron spectroscopy(XPS), x-ray diffraction(XRD)and transmission electron microscope(TEM), and electrocatalytic activity of Pt/C catalysts toward methanol oxidation were measured by cyclic voltammetry(CV). The results indicate that，through the oxidation treatment, the chemical composition and chemical state of carbon black are both changed, the concentration of surface oxygen-containing function group increases, the increased oxygen-containing function groups offer more anchor sites for Pt deposition, improve the dispersity of Pt nanoparticles on the surface of carbon black supports, decrease the size of Pt nanoparticles, and cause the reduction of the PtO content in Pt/C electrocatalysts, thus enhance the electrocatalytic activity of Pt/C electrocatalysts toward methanol oxidation.
  • Study on shielding properties cement-based composites doping carbon materials
    xiong guo xuan ;
    . 2011, 42(01): 43-0.
    Abstract ( ) Knowledge map Save
    Shielding mediums, such as graphite, carbon black, carbon fibre, nano-carbon-tube and so on were dispersed by different method, and the cement-based composites shielding materials is made of cement and carbon materials. The effect of ordinary carbon materials on shielding properties was studied and the relationship of different contents of carbon fibre and nano-carbon-tube with shielding effectiveness was discussed. The conductivity of cement-based composite materials and uniformity distribution of shielding medium were characterized by four-point probe meter and electron probe X-ray microanalyzer. The results show that the electric performance of cement-based composites doping carbon fibre are best than specimens of doping nano-carbon-tube and ordinary carbon materials. When contents of carbon fibre reach 5%(vol), shielding properties of specimens is best in 100 KHz~1.5 GHz frequency range, average shielding effectiveness is about 37 dB and maximum shielding effectiveness is 40 dB.
  • Preparation of Nano-alumina thin film humidity sensor
    . 2011, 42(01): 44-0.
    Abstract ( ) Knowledge map Save
    Abstract：A humidity sensor based on porous A12O3 thin film was investigated. The porous A12O3 thin film was fabricated using electronic chemical etching. Two-step anodic xidation and unique post treatment obtains the hole distribution even aperture size consistent also bears the hydration the porous oxide film. Humidity sensing properties of the sensor: Sensor less than 2% wet delay, Response time less than 10s, recovery time is less than 40s, the performance is very good.
  • STUDY ON THE INFLUENCE OF DIFFERENT PROPERTY OF AMPHIPHILIC NANO-SIZED TiO2 COMPOSITE PARTICLES ON STRUCTURE AND PROPERTIES OF PVDF ULTRAFILTRATON (UF) MEMBRANE
    ZHAN Hanhui
    . 2011, 42(01): 45-0.
    Abstract ( ) Knowledge map Save
    The amphiphilic PAA-gaft-PMMA-gaft-silane coupling agent KH570-gaft-nano-sized TiO2 composite particles was synthesized via to the method of non-soap emulsion polymerization,and through adjusting the rate of AA and MMA to control the surface properties of composite particles. The influence of nano-sized TiO2 composite particles with different surface properties on the structure and properties of PVDF UF membranes had been studied through the characterization of FTIR、contact angle、SEM and membrane permeation test The results showed that the hydrophilic of complex enhanced, the hydrophilic of modification membrane gained well effect, and the flux was with the content of acrylic acid (AA) was increasing in the hydrophilic chain. But it was easy to form a hole and decrease the retention rate and the compaction property of modification membrane. While for the increasing content of methyl methacrylate (MMA) in the hydrophilic chain, the hydrophilic of modification membrane was poor effect and the flux was low, but the compaction property of modification membrane was well. Thus, when the suitable proportion of two monomers was 40～60%, the modified PVDF UF membrane had excellent properties and the flux and the retention rate reached 80ml.cm-2.h-1 and 80%, respectively.
  • A study of anticoagulant properties on carboxylated graphene oxide-La composite
    . 2011, 42(01): 46-0.
    Abstract ( ) Knowledge map Save
    In this paper, a functional graphene oxide was prepared with La3+ ions and the carboxylated graphene oxide sheet. The structure and properties of GeneO-La composite was characterized by Fourier transformed infrared Specttroscopy (FT-IR) and Transmission electron microscopy (TEM); The functional graphene oxide was added to anticoagulation system and its effects on anticoagulant properties were studied. Results show that the La3+ ions have been coordianated on graphene oxide sheet layer. The blood compatibility of the GeneO-La composite was evaluated by plasma recalcification time test and hemolysis test. It was observed that the plasma recalcification time gradually shortened with the increase in the concentration of composite, and hemolysis rate were less than 5 % in lower concentrations, it conformed to the Hormesis effect of rare earth elements. Therefore , the GeneO-La composite is a new carboxylated graphene oxide composite, which has anticoagulant effect when it has lower concentrations.
  • Growth and Optical Spectra of Eu3+-doped Near –stoichiometric Lithium Niobate Crystal
    . 2011, 42(01): 47-0.
    Abstract ( ) Knowledge map Save
    The near-stoichiometric LiNbO3 single crystals doped Eu3+ in 0.95mol％ concentration in the raw compositions were grown by the Bridgman method under the conditions of taking K2O as flux , and taking high temperature gradient of about 90 ~ 100℃/cm of the interface as seeding and growing of the crystal. The Eu3+ ion concentrations, the absorption spectra, excitation spectra and emissions of Eu3+-doped near-stoichiometric LiNbO3 were measured. Two absorption peaks at 394nm(7F0—5D3), 468nm(7F0－5D2) and the level transitions of Eu3+ from 7 F0 to 5D4 、5 G3 、5L6 、5D3 、5D2 、5D1 and 5D0 level were obtained from their absorption and excitation spectra. The content of Li2O in crystal, to be 49.47mol%, was estimated from the absorption edge of Eu3+-doped LiNbO3 crystal. The sharp emission peaks from5D0 to 7FJ (0，1，2，3，4) were observed under excitation of 394nm light. It could be deduced that the Eu3+ concentration increased gradually along growing direction by comparing the absorption and emission intensity, and the measured Eu3+ ion concentrations between the upper and lower parts of the crystal. The effective distribution coefficient of Eu3+, to be ~1.02, was estimated from the measured Eu3+ ion concentration.
  • Study on the structures and properties of wool fiber with Ag-loading MWNTs antibacterial agent
    . 2011, 42(01): 48-0.
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