25 September 2010, Volume 41 Issue 09
    

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    研究与开发
  • Studies on the Electro-catalytic Performance of Pt-carbon aerogel by Microwave Synthesis
    Guo Zhi-Jun ;;;
    . 2010, 41(09): 1-0.
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    In this work, carbon aerogel (CA) as the catalyst support was synthesized via a sol-gel process from resorcinol and formaldehyde catalyzed by Na2CO3, and then dried at ambient pressure and heated at 1050℃ for 4 h in flowing N2. Pt/CA catalysts were prepared by intermittent microwave heating method. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) measurements show that the catalyst particles were homogeneously distributed. The electrochemical measurements show that the activity of Pt/CA catalyst is better than that of Pt/C catalyst.
  • Preparation and Properties of Chitosan-based Tissue Engineering Corneal Carriers
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    . 2010, 41(09): 2-0.
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    Crosslink the soluble chitosan (D.D.≈50%) as main ingredient with gelatin and chondroitin sulfate to obtain three kinds of blend membranes at different proportions. Then, test transparency,water content,cytotoxicity, cytocompatibility with the rabbit keratocytes and tissue compatibility. Results show that the blend membrane with the volume ratio at 9:1:0.1 of Cts-Gel-CS has good optical transmittance,suitable water content,no cytotoxicity and better cytocompatibility with the rabbit keratocytes. Animal tissue compatibility experiments showed that no remarkable inflammation appeared. In conclusion,this blend membrane is a promising carrier of corneal cells to reconstruct tissue engineering cornea.
  • Effects of PP-g-MAH and rare earth nucleating agent on polypropylene/calcium sulfate whisker composites
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    . 2010, 41(09): 3-0.
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    Effects of compatibilizer PP-g-MAH and rare earth β-phase nucleating agent on crystallization and melting behavior and mechanical properties of polypropylene/calcium sulfate whisker composites were investigated. It was found that the calcium sulfate whisker had a heterogeneous nucleation effect on the polymer matrix and induced the formation of β-crystal, increasing the peak crystallization temperature and the overall rate of crystallization of PP. PP-g-MAH improved the interfacial compatibility and tensile strength, enhanced the nucleation activity of the whisker in the PP matrix, and increased the content of β-PP. The results showed that rare earth β-phase nucleating agent resulted in dominant β-PP and improved effectively the impact strength.
  • Electrochemical Behaviors of Electrodeposited Fe-Ni alloy
    陈 志 凯
    . 2010, 41(09): 4-0.
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    Electrochemical behaviors of Fe-Ni alloy electrodeposition in different of Fe2+, Ni2+,pH, temperature, brightener, complexant were studied by the methods of linear potential sweep, cyclic voltammetery. From the results it can be concluded that when pH value decreased and temperature increased, the cathodic polarization of Fe-Ni alloy electrodeposition decreased. With increasing the concentration of Fe2+ and decreasing the concentration of Ni2+, the cathodic polarization increased. Brightener and complexant played a role of increasing cathodic polarization and were useful to make Ni-Fe alloy brighter and density. At the same time they could enhance corrosion resistance of coatings. The apparent active energy of the electrode reaction of electrodepositon Fe-Ni alloy coating within an electrode potential range of -1.0v to -1.2v was calculated to be above 40kj/mol, indicating that the electrodepositon process of the Fe-Ni alloy coating was dominated by electrochemical polarization. The XRD pattern showed that Ni-Fe alloy was a solid solution with a crystal structure, the SEM pattern indicated that its appearance was smooth and bright.
  • Synthesis and Characterization of poly (bithiophene-co-diphenoquinone diimine)
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    . 2010, 41(09): 5-0.
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    Two new alternative -conjugated copolymers were synthesized by nickel (II) complex catalyzed polycondensation of N,N′-dichlorodiphenoquinone diimine or 3,3′-dimethyl- N,N′- dichlorodiphenoquinone diimine with 5,5′-dibromo-2,2′-bithiophene. The monomers were prepared from corresponding benzidines. The copolymers were characterized by UV-Vis, FT-IR, 1H NMR and cyclic voltammogram. The copolymer I (in DMSO) showed two absorption peaks at about 330 nm and 437 nm, respectively, while copolymer II showed two absorption peaks at about 327 nm and 410 nm, respectively. The results from cyclic voltammogram in the range of -0.1～0.8V showed that each polymer had two symmetric reduction and oxidation peak in which Epa=0.40V/Epc=0.31V and Epa=0.70V/Epc=0.56V for copolymer I, and Epa=0.33V/Epc=0.28V and Epa=0.63V/Epc=0.50V for copolymer II, respectively.
  • Study on Microstructure of Electric Brush Plated Nano-diamond/Ni Composite Coating
    Li Ying
    . 2010, 41(09): 6-0.
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    The surface morphologies of 45# steel-based composite with nano-diamond/Ni electro brush-plating and general Ni composite coating were studied. By scanning electron microscopy analyzing, the results showed that the surface of nano-diamond/Ni electro brush-plating is typical “cauliflower” morphology and the nano-diamond particles are enwrapped by the dispersive nickel grains. Because the partial nano-diamond particles can regard as the non-spontaneous nucleation base of the nickel atom and can attract more nickel ion to deposit and nucleate, then them offer a great deal of crystallization growth point so as to achieve the refined grain effect. Therefore, comparing with the general Ni composite coating, the surface of nano-diamond/Ni electro brush-plating is more smooth and compact, and the crystal structure is finer. The results of X-ray diffraction further proofed that the grain sizes of composite coating gradually become smaller with the content of nano-diamond increasing. Further, the physical model of growth process on nano-diamond/Ni electro brush-plating was built according to the experimental result.
  • Effect of Zn buffer layer on the structural and optical properties of ZnO thin films
    ; ;;;
    . 2010, 41(09): 7-0.
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    Abstract: The ZnO films with different Zn buffer layers thickness were prepared on glass substrate by RF magnetron sputtering system. The micro-structural and optical properties were determined by x-ray diffraction (XRD), Scanning electron micrography (SEM) and photoluminescence spectra (PL). XRD measurements revealed that the full width at half maximum (FWHM) of the (002) peak films gradually decreased as the thickness of buffer layers increased, indicating that crystal quality of ZnO films was improved. Blue double-peaks centered at 435nm（2.85eV）and 480nm(2.58eV) , and green peak centered at 530nm(2.34eV) were observed from the PL spectra. 15 minutes is the most suitable time for the Blu-ray monochromatic nature of the deposition. We could speculate that the blue emission centered at 435nm was mainly due to the electronic transition from interstitial Zinc (Zni) defect to the top of the valence band. The green emission was mainly derived from oxygen vacancies.
  • The Study of the Structure influence of Surface-modified Gold/Silica Nanoshells with the Small Functional Molecules
    ;Shun-Ying Liu ;;;
    . 2010, 41(09): 8-0.
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    Gold nanoshells'surface were modified by different functional small molecular containing mercapto group respectively, such as cysteamine (Cys), cystamine (CYS), mercaptosuccinic acid (MSA), and mercaptoethanol (ME). The investigations of dynamic light scatter (DLS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and UV-vis spectra demonstrated that Cys and CYS with amine groups presented a significant devastation on the core/shell structure of gold nanoshells, which lead to the obvious aggregation and the disappearance of the NIR resonance of the nanoparticles. However, the surface-modification with MSA and ME had no obvious effect on the core/shell structure and the NIR response of the gold nanoshells. It is possibly due to the bonding of amine groups in Cys and CYS with the gold layers of the nanoshells by electrostatic and coordination interaction.
  • Preparation and Drug-controlled Release of Hydrophobically Modified Alginate
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    . 2010, 41(09): 9-0.
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    In order to increase the loading dose of hydrophobic drugs on alginate and control the drug release rate, sodium alginate was hydrophobically modified with n-octylamine through the reaction of carbodiimide. The modified alginate was characterized with FTIR and 1HNMR. The modified alginate was made into microsphere beads in aqueous solution of 3wt% calcium chloride. A hydrophobic drug of ibuprofen was loaded on the modified alginate for the in vitro investigation on the drug-controlled release. The results indicated that the drug-loaded dose was obviously increased and the release rate could be well controlled.
  • Pure Cu braze for sealing oxygen-permeable membrane ceramics and stainless steel support
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    . 2010, 41(09): 10-0.
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    Abstract: Pure Cu braze was used to seal oxygen-permeable membrane ceramics and stainless steel support. The thermal expansion coefficients of Cu braze, oxygen- permeable membrane and stainless steel were tested. The interfacial morphology of oxygen-permeable membrane and Cu braze after brazing in air was observed. The hermeticity and stability of joint were investigated during oxygen permeating. The results show that their thermal expansion coefficients are similar. No cracks have been found at the interface of Cu braze and oxygen-permeable membrane after brazing. A reaction layer due to Cu diffusion on the membrane side has been observed and the thickness of this reaction layer is about 350 μm. The jointing interface is gas-tight after oxygen permeating for 10h and the thickness of reaction layer on the BCFNO side keeps invariable.
  • Evolution of microstructure during Sequential Motion Compaction process for large demensions porous 7090Al/SiCp composite
    youping sun ;
    . 2010, 41(09): 11-0.
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    On the basis of the conception that a large deformation could be obtained through the accumulation of many times of small deformation, the distribution of SiC particles and the deformation of the pores during the sequential motion compaction of the large dimension spray co-deposited 7090Al/SiCp composite were investigated. Wedge pressing resulted in the local deformation, which led to the shear deformation and the closure of pores. Ultimately the pores were eliminated and the densification was realized. The SiC particles rotated under the pressing force and exhibited an order distribution with the long axis perpendicular to the pressing direction. When thickness reduction is about 40%, the ultimate tensile strength and yield strength of the composite are 250Mpa and 175Mpa, respectively, and the elongation is 3.8%, the relative density is 91.76 percent
  • Effects of Foaming Temperature on the Properties and Structure of Mesophase Pitch-derived Carbon Foams
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    . 2010, 41(09): 12-0.
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    Four carbon foams were manufactured through AR mesophase pitch powder with initial foaming pressure 3 MPa and foaming temperature at 390-450 ℃. Their pore structures were observed with SEM. The bulk density, compressive strength and thermal conductivity were measured, and effects of foaming temperature on the properties and structure of carbon foams were studied. Results show that lower foaming temperature, no higher than 430 ℃, was helpful to eliminate big pore defects. The optinum foaming temperature was 410 ℃. Carbon foam prepared at the temperature had the largest thermal conductivity, 0.256 W?m-1?k-1.
  • Photoelectric properties of PEDOT prepared through a modified LB film method
    . 2010, 41(09): 13-0.
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    An arachidic acid (AA)/PEDOT multilayer LB film was firstly prepared through a modified LB film method. UV-Vis, FT-IR, XPS, XRR and SIMS investigation indicated that polymerization of EDOT monomer occurred in nanospace between hydrophilic groups of AA molecular and well ordered PEDOT multilayer film is formed. The reduced ordered structure happened during polymerization of EDOT, which may be caused by a deformation of ordered AA LB film. A four-probe method and semiconductor testing system were used to investigate conductive performance of LB film. Abrupt change of conductivity during the polymerization of EDOT in LB film was observed and this phenomenon may result from an instant connection of conducting channel. It also has been found that AA/PEDOT film exhitbited better conductive ability than ODA-SA/PEDOT-PSS film and spin-coating PEDOT/PSS film, which due to the higher π structure of PEDOT structure and ordered film structure.
  • Preparation of glycyrrhizic acid carboxymethyl chitosan nanoparticles and its characteristics
    ZHANG Xue Qiong;;;
    . 2010, 41(09): 14-0.
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    The carboxymethyl chitosan nanoparticles were prepared through ionic gelification with calcium ions. The orthogonal test design was used to optimize the preparation process. The shape of the nanoparticles were studied by TEM. Nanoparticle size was evaluated by laser particle size determination. The high performance liquid chromatography was used to detect the drug-loading rate and entrapment efficiency of particles, and the in vitro release was investigated. The results show novel nanoparticles were spherical, average in particle size (131.2±5.27)nm, entrapment efficiency (51.2±0.41)%, drug-loading capacity (16.7±0.29)%, sustained release of carboxymethyl chitosan nanoparticles is significant.
  • Simulation study on the solidification process of Al-Bi monotectic alloys under non-gravity and gravity conditions
    KANG Zhi Qiang
    . 2010, 41(09): 15-0.
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    Base on the mechanism of liquid-liquid decomposition and separation in the immiscible gap during the solidification process of Al-Bi monotectic alloys, using Eulerian approach to develop a numerical model on the microstructure evolution. This model includes nucleation, diffusion growth, Stokes motion, Marangoni motion and gravity sedimentation of L2 phase, which result in macrosegregation during the real solidification process. The simulation results indicated that Marangoni force drives the droplets to move from the cold towards the hot region under non-gravity conditions, however the droplets move as symmetry circumfluence pattern under gravity conditions. As cooling time proceeds, gravity-induced droplet sedimentation leads to volume fraction and diameter of L2 phase increase obviously at the lower corner. Comparing with gravity condition, Non-gravity condition is advantage for nucleation of L2 phase.
  • TiC-TiB2-Ni/TiAl/Ti gradient functionally materials Synthesized by In-situ Synthesis Via Field-Activated and Pressure-Assisted Synthesis
    ZHANG nan;Meng qing sen
    . 2010, 41(09): 16-0.
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    TiC-TiB2-Ni/TiAl/Ti gradient functionally materials (FGMs) were prepared by field-activated pressure-assisted synthesis (FAPAS) and in-situ synthesis processes. The effects of the electric field on material synthesis and diffusion bonding of layers have been investigated. The microstructure and phase constitution of each layer as well as elements distribution across the interfaces were analyzed by means of OM, SEM, EDS and XRD. The results show that the imposition of the electric field and the combustion reaction of TiAl is the key for the successful synthesis during process; the TiC-TiB2 particles formed by in-situ synthesis process were fine and distributed uniformly; moreover, concentration profiles of elements across the interfaces of the layers show significant inter-diffusion and good metallurgical bonding. The sample has a gradient distribution of micro-hardness across the titanium substrate to the surface layer.
  • Preparation of self-assembled sodium alginate nanoparticles and the study on a nano-delivery vehicle for rotenone
    . 2010, 41(09): 17-0.
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    Abstract：Deoxycholic acid modified sodium alginate (DSA) is synthesized by reacting with deoxycholic acid, which is activated by N’N-dimethyl formamide (DMF), with the carboxyls on sodium alginate main-chain when 1-ethy-3-(3-dimethyl-aminopropyl)carbodiimide (EDC) as a coupling agent. The amphiphilic polymers can form aggregates which have a nuclear-shell structure in solution. Atomic Force Microscopy and laser light scattering results demonstrate that the aggregates are nanoparticles and the diameter is mainly about 200nm.The critical aggregate concentration (CAC) of DSA is very low. The higher the degree of substitute, the lower the CAC is confirmed by the results of fluorescence spectrum. The loading efficiency is very well when the DSA is used as a nano-delivery vehicle for rotenone.
  • Studies on the Selective Laser Sintering of High Molecular Weight Poly（D, L-lactic acid）
    . 2010, 41(09): 18-0.
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    This research focus on the use of a biocompatibility material, Poly（D, L-lactic acid）(PDLLA),to fabricate tissue engineering scaffolds using selective laser sintering (SLS) rapid prototyping(RP). This particular form of PDLLA has a high molecular weight of 80000, a melting point of 100℃, and the largest particle size of 120μm. Effects of process parameter on the forming qualities were investigated. The parameters of the SLS process are optimized to cater to the process of manufacturing test specimens and human ear like scaffold. Optimal sintering conditions for the powders were achieved by varying parameters such as the part bed temperature, laser power, and scanning speed. GPC-Multi-angle laser light scattering equipment and FTIR analysis was used to check the molecular weight and the chemical composition of PDLLA before and after sintering. Compression tests were performed using an Instron to analyze the mechanical properties. The mechanical properties were evaluated by using compression tests. The microstructure was characterized by using the scanning electron microscopy. This analysis confirmed that the molecular weight was reduced partly and its distribution was broadened. FTIR indicated that the chemical component of the sintered specimen was not changed. Mechanical testing showed that the sintered specimen reserved 20% modulus of compression of the specimen before sintering. SEM micrograph showed that the sintered PDLLA artificial ear with porous structure. The successful sintering of the test specimens shows the potential of producing PDLLA scaffolds on the SLS.
  • Properties characterization of Ag0.8PbmSbTem+2 thermoelectric materials via rapid hot-pressing sintering
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    . 2010, 41(09): 19-0.
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    Micro-sized powder of n-type Ag0.8PbmSbTem+2 (m=12,14,16,18) alloy was fabricated via a vacuum sealed melting method combined with high energy ball milling. Rapid hot-pressing sintering was employed to prepare bulk thermoelectric materials at 673 K with sintering pressure of 20 MPa, and time of 30 min, respectively. The influence of rapid hot-pressing sintering method and variation in the value of m on the structure and the thermoelectric properties was investigated. The maximum seebeck coefficient of -634μV/K is obtained at 348 K with m equaling to 16. The power factor reaches a maximum value of 7.5×10-4 Wm-1K-2 at 548 K for an m of 18.
  • Synthesis of Hierarchical Porous ZnO by Dual Template Method and Its Electroluminescence Characteristics
    ; ;
    . 2010, 41(09): 20-0.
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    ZnO precursors were synthesized by a sol-gel method using Pluronic P123 as mesoporous template in this paper. Then filled the polystyrene(PS) template which was self-assembled from PS spheres with the as-prepared ZnO precursors. The gel of polystyrene/inorganic was completed at 55℃ in the drying oven. Hierarchical meso-macroporous ZnO were obtained after the decomposition of the organic template, i.e. PS and P123, by calcining at 600℃ for 10h. The as-prepared samples were characterized by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR). The electroluminescence results indicate that the EL emission intensity of calcined hierarchical porous ZnO is 2.3 times higher than mesoporous ZnO under the same elecric field intensity.
  • Preparation and Property Study of CdS Quantum Dot Sensitized Nanocrystalline TiO2 Heterostructure Films
    JIN Li-guo
    . 2010, 41(09): 21-0.
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    Abstract: Nanocrystalline TiO2 solution was prepared by hydro-thermal treatment at 230℃ with Titanium(Ⅳ) isopropoxide (C12H28O4Ti) as precursor solution. Anatase TiO2 nanocrystalline films with hierarchical structure were prepared on FTO glass substrates by electrohydrodynamic (EHD) technique and sintered at 450℃. CdS quantum dot sensitized nanocrystalline TiO2 heterostructure films were deposited by chemical bath method using the Cd(NO3)2 solution and Na2S solution as the reactants. The crystal structure, morphology and optical property of the film were investigated. The results indicate that nanocrystalline TiO2 films stack with the submicron spherical clusters, submicron and nanometer channels with wide dimension formed among the clusters which can facilitate the solution facilitation and ions adsorption. Nanocrystalline TiO2 heterostructure Films exist with CdS quantum dots with the range of 3-5nm. UV–vis absorbance spectra verified the blue shift of heterostructure Films due to the quantum confinement effects of quantum dots
  • Preparation and Growth Mechanism of Self-assembled F-doped TiO2 Microspheres via Gel-Microwave-assisted Hydrothermal
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    . 2010, 41(09): 22-0.
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    Abstract: The self-assembled mesoporous microstructures of F-doped TiO2 microspheres were synthesized via gel-microwave-assisted hydrothermal method. The as-synthesized samples were characterized by SEM, TEM, XRD, XPS and PL. The growth mechanism of F-doped TiO2 microspheres and its mesoporous microstructures was also briefly analyzed. The results showed that the average diameter of microspheres were about 400 nm. Since sodium fluoride doped, nanocrystals(12 ± 0.5 nm) and mesoporous (≈ 10 nm) formed and roughness clearly enhanced. The PL spectra show F does not result into a new PL phenomenon, but F dopant can enhance the PL intensity of TiO2 microspheres．The PL spectra showed that the as-prepared samples exhibited broad blue emission at 396nm and 464nm, and its photoluminescence property was highly related to its microstructures.
  • The preparation and microstructure of CNTs/HAp biocomposite coating
    ;
    . 2010, 41(09): 23-0.
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    The composite coating of CNTs/HAp has been prepared on a tiianium sbustrate by the method of electrophoretic deposition technique. The results of XRD indicated that after sintering at 800 ℃for 2 h in argon the main component of the composite coating is hydroxyapatite and canbon nano-tube. Micrograph of composite coating expressed that the composite coating is symmetrical and compact. CNTs was dispered in hydroxyapatite particles symmetrical and CNTs was coated uniformity by hydroxyapatite. With the content of carbon nanotube increased from 20 percent to 50 percent the density of the composite coating increased gradually and the surface quality improved gradually.
  • Study on Static/Dynamic Mechanical Properties and Constitutive Relation of Vacuum Rubber
    . 2010, 41(09): 24-0.
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    Quasi-static tests via MTS test system and SHPB experiments on the physical properties of vacuum rubber were carried out. Basic mechanical parameters and stress-strain curve of the rubber were obtained through experiments. The static and dynamic constitutive model was presented based on necessary analysis of deformation behavior of materials, strain-rate-related effects and destruction properties. It provides bases for engineering applications of these materials and further improvement. The results show that: strain rate effect of vacuum rubber material is not obvious under quasi-static loading with stress less than 3MPa; strain rate effect is more obvious under shock loading with increasing strain rate and higher slope of stress-strain curve; vacuum rubber also has significant strain-rate hardening effect.
  • Preparation and property of S-doped ordered porous TiO2 by microwave treatment
    jiang xueliang
    . 2010, 41(09): 25-0.
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    In the paper, the porous TiO2 materials were prepared by colloidal crystal template method, and S-doped porous TiO2 with visible light catalytic activity was obtained by microwave radiation. The S-doped porous TiO2 materials were characterized by SEM, XRD and XPS. The results showed that the colloidal crystal template is ordered which prepared by polystyrene with hydroxide radical, the porous TiO2 materials are densification and regulation. The crystal formation of porous TiO2 did not change by microwave treatment, which is anatase. XPS analysis showed that S-doped TiO2 could be prepared by microwave irradiation and the content of S element is 1.44%. The photocatalysis property of S-doped TiO2 is better than that of the pure TiO2.
  • Preparation and electrochemical performance of LiFePO4/polythiophenes composites
    CHEN Han
    . 2010, 41(09): 26-0.
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    LiFePO4/PTP composites were prepared successfully by in-situ chemical polymerization. The interaction and coating condition between LiFePO4 and PTP were investigated systematically by Fourier Infrared spectroscopy (FTIR) and High Transmission Electron Microscopy (HRTEM). The electrochemical performances of composites were tested by electrochemical impedance spectroscopy and galvanostatic charge and discharge methods. The experimental results show that uniform coating layers were formed applied 9.6% PTP. It possesses the bestelectrochemical performance, good rate and cycling capability. Its initials discharge capacity is 158.2 mAh/g at C/12 rate.
  • A Study on the Preparation and Photocatalytic Properties of Au/TiO2 Composite Fibers
    Zhao Gaoling;Zhao Gaoling
    . 2010, 41(09): 27-0.
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    TiO2 fibers and Au/TiO2 composite fibers were developed via sol-gel approach. Their crystallization properties and surface morphology were characterized with XRD, SEM and TEM, and the activity was investigated by the photocatalytical degradation of methyl orange as probe. The results demonstrate that TiO2 is anatase after the heat treatment, and the size of Au particles is 7~15 nm. The diameter of fiber is 5~20 μm and the length is 5~50 cm. The incorporation of Au could greatly enhance the photocatalytic activity of TiO2, which increased with the addition of Au incorporation.
  • Analyzing on the stabilities of sintered NdFeB magnets as the vehicle permanent magnetic sensors
    ;Chang Ying;;;;min qi
    . 2010, 41(09): 28-0.
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    The effects of electromagnetic disturbance, vibrating and temperature on the permanent magnetic properties were investigated. The results show that ① The magnetic properties decrease as external magnetic field or frequency increase, and the magnetic loss gets more in alternating magnetic field; ② The irreversible thermal demagnetization of the permanent magnets would happened, due to skin effect of eddy current in alternating magnetic field. Demagnetization would be raised rapidly over 15% when being in 30kA/m、500Hz magnetic field; ③ Demagnetization raised larger as magnets were affected by both vibrating and high temperature.
  • Preparation of superhydrophobic surface on silicon based on laser manufacturing and self-assembled technique
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    . 2010, 41(09): 29-0.
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    Silicon substrate were processed into regular surface texture with lattice structure by Laser manufacturing. Self-assembled monolayers of perfluorooctyltrichloroslane were prepared on texturing surface by self-assembled method. Scanning electron microscope and surface profiler were used to analyse the surface properties of specimen. The characterization of the contact angle were conducted by contact angle measurement. The results indicate that depth of the texturing surface and surface roughness increase with pitch increasing after laser manufacturing. The volume loss of specimen surface increase with irradiation time increasing. After laser manufacturing and self-assembled monolayers preparation, the contact angles of the water droplet on the substrates increase significantly. The maximum contact angle reached 156°, and the contact angles increase with pitch decreasing. The values of contact angle measurement are in accord with the Cassie model’s prediction. It’s in superhydrophobic state when the ratio of diameter and pitch is less than 0.510.
  • Controllable Preparation of Polystyrene Microspheres
    ;
    . 2010, 41(09): 30-0.
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    emulsifier-free polymerization approach and two-step emulsion polymerization approach were developed to fabricate highly monodisperse polystyrene (PS) spheres using potassium persulfate(KPS) as the initiator, polyvinylpyrrolidone (PVP) as stabilizer and sodium dodecylsulfate(SDS) as emulsifier, respectively. The effects of the dosage of initiator, stabilezer and emulsifier on diameter of the PS spheres were discussed. It was found that the size of monodisperse PS spheres tends to decrease with increase of the KPS, PVP, SDS concentration, while the distribution of PS spheres changes little. By adjusting the dosage of KPS, PVP and SDS, the size of PS spheres could be easily controlled in a wide range from 10 to 1000 nm.
  • Effect of concentrated acid oxidation on field emission properties of carbon nanotubes
    Yun YEYou Yu Xiang;
    . 2010, 41(09): 31-0.
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    The effect on field emission properties of carbon nanotube (CNT) oxidized by HNO3 and HNO3-H2SO4 were investigated by TEM, Raman and XPS. The results showed that the impurity of catalyzer and amorphous carbon had been eliminated by the oxidation of HNO3 or HNO3-H2SO4. For the effect of oxidization and dehydration of H2SO4, the higher disorder degree and more disfigurement density were obtained of carbon nanotubes treated by HNO3-H2SO4 than that of those treated by HNO3, with the oxidized groups such as C—OH, C=O and O=C—OH in existence of surface. The turn-on field of carbon nanotubes treated by HNO3-H2SO4 is 1.1 V/μm, which is lower than that of those treated by HNO3 as 1.7 V/μm. The corresponding emission current density is 1.8 mA/cm2 and 4.2 mA/cm2 for carbon nanotubes treated by HNO3 and HNO3-H2SO4, respectively, while the applied field increased to 3.0 V/μm.
  • Preparation and photoelectric properties of transparent conductive yttrium-doped zinc oxide thin films
    ;Tianlin Yang;;;; ;
    . 2010, 41(09): 32-0.
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    A new transparent conducting oxide (TCO) film with low resistivity and high transmittance in the visible range, yttrium-doped zinc oxide (YZO), was successfully prepared by RF magnetron sputtering on glass substrates at room temperature. The dependence of the electrical property of the films on the deposition pressure and power was investigated. X-ray diffraction (XRD) pattern shows that the YZO film is polycrystalline with a hexagonal structure and has a preferred orientation along the c-axis. The film, with a low resistivity of 8.71×10-4 Ω cm and a high transmittance of 92.3% in the visible range, has been obtained.
  • The Characterization and Analysis in Surface of Ultra-fine Electronic Fiberglass
    ;QIU Lin;;;;
    . 2010, 41(09): 33-0.
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    The surface morphology of ultra-fine electronic fiberglass (D450)，which include original fiberglass and uncovering fiberglass，were observed by Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and Atomic Force Microscope (AFM). The morphology characteristics and their causes of formation were analyzed. The results show that: (1) In the OM images, the fiberglass seem as smooth cylindrical and the details cannot be present; in the low magnification SEM images, the fiberglass seem as approximate cylindrical; in the high magnification SEM images and AFM images, the fiberglass surface seems orange skin. (2) In all OM and SEM and AFM images, no crack was observed in the surface of ultra-fine electric fiberglass. (3) In the OM images, the sizing agent layer on the fiberglass cannot be observed easily; In the SEM image, much sizing agent layer seems as smooth and continuous film and a little granular and flaky salient can be observed.
  • Preparation and Electrochemical Properties of Hydrous Ruthenium Oxide/ Activated Carbon Electrode Materials via Hydrothermal and Microemulsion Physical Mixing Methods
    Chen chen Wang ;;;;
    . 2010, 41(09): 34-0.
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    Composite electrode materials of hydrous ruthenium oxide/activated carbon(HD and MP) were prepared by hydrothermal and water-in-oil reverse microemulsions-physical mixing deposition method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen adsorption-desorption at 77 K were used to investigate the structure, morphology, specific surface area and pore size of the composites. Their electrochemical properties were evaluated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The results showed that a thin layer of RuO2?xH2O was well deposited on the AC in the hydrothermal process. HD is superior to MP obviously. The specific capacitance of HD could be as high as 337 F.g-1, 39.6% higher than that of MP electrode when the current density is 3 mA.cm-2. The power density of HD could reach 1072 W.kg-1 22.5% higher than that of MP electrode when the current density is 60 mA.cm-2, which means that HD is suitable for fast charging and discharging at large current. The HD composite electrode had a small resistance, high stability, after a 1000-cycle charge-discharge, the capacity retention was of 99.8%.
  • Hydrothermal synthesis of Ba1-xPbxWO4 microcrystallines and their luminescent properties
    . 2010, 41(09): 35-0.
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    Abstract: Ba1-xPbxWO4 solid solution microcrystallines were synthesised by hydrothermal method; the crystal structure, surface morphology and room temperature photoluminescence properties of the as-synthesized microcrystallines were investigated by through X-ray diffraction(XRD), scanning electron micrograph(SEM) and fluorescence analysis(FA). Our results show that the morphology of Ba1-xPbxWO4 microcrystallines changed from taper-like to the dendritic when x changed from 0 to 1.0. With the excitation of 270nm ultroviolet irradition, the emission specta of Ba1-xPbxWO4 microcrystallines all exhibit two emission peaks: one is the weak emission peak located at about 320nm and the other one is the strong emission peak located at around 400 ~ 470nm. The former is intrinsic emission peak of WO42-complex ion, and its intensity and wavelength are less change with the variety of x; while the latter is an activation emission peak of the doping Pb2+and the doping level of Pb2+(i.e.x) has significant influence on the emission intensity and wavelength of the emission peak. When x=0.03, the Ba1-xPbxWO4 microcrystalline show the maximal emission intensity.
  • Fabricating Ag/Al composite powder by electroless silver plating
    ;;
    . 2010, 41(09): 36-0.
    Abstract ( ) Knowledge map Save
    Silver-coated aluminum powder was gained by electroless plating. The principle of electroless silver plating on aluminium powder was studied and the influences of ammonia,argentamine ,stabilizing agent, temperature and pH value on electroless silver plating was investigated. The results show that ammonia can strength stability of plating bath and improve the micrographics of immersion silver coating, argentamine concentration has great influences on the resistivity and content of silver , little stabilizing agent can improve stability of plating bath while more stabilizing agent leads to loose silver coating layer , the temperature and pH value can increase the amount of deposited silver but bring about decomposition of plating bath.
  • The Influences of Sterilization Methods on The Properties of Multi-(Amino Acid) Copolymer
    Hong Li; ;
    . 2010, 41(09): 37-0.
    Abstract ( ) Knowledge map Save
    The multi-(amino acid) copolymer was sterilized by alcohol, ultraviolet exposure, steam, ethylene oxide, gamma ray. The effects of sterilization methods on the properties of the copolymer were investigated by mechanical test, viscosity number, FT-IR and XRD determination. The results show that the viscosity number and the compressive strength significantly are changed (P<0.05) and the crystallinity is also changed by alcohol sterilization; Steam sterilization significantly decrease the compressive strength (P<0.05); Cross linking occurs and the viscosity number markedly increases afterγ－ray radiation. Ultraviolet exposure increases viscosity number. Ethylene oxide sterilization shows no noticeable effects on the properties of copolymer and therefore it can be candidates for multi-(amino amide) copolymer sterilization.
  • Gas-sensing properties of Sr-doped LaFeO3 preparated by microwave chemical synthesis process
    . 2010, 41(09): 38-0.
    Abstract ( ) Knowledge map Save
    Sr-doped LaFeO3 powder was prepared by the method of microwave chemical synthesis. The crystal structure and morphologies of Sr-LaFeO3 were characterized. The results show that the La0.91Sr0.09FeO3 was pure perovskite structure, the dispersive of La0.91Sr0.09FeO3 particle is uniform and the particle size is about 65nm. The sensitivity and selectivity of La0.91Sr0.09FeO3 for 10 ppm toluene are good, and the response-recovery times are about 40 and 50s, respectively.
  • Preparation of titanium carbide powders in high-frequency induction furnace
    Wei Sen; ;;;
    . 2010, 41(09): 39-0.
    Abstract ( ) Knowledge map Save
    Formation of ultrafine TiC powders by carbothermal reduction of Titania and charcoal in high-frequency induction furnace was investigated by XRD, SEM/EDS, Atomic Absorption Spectrometer, XRF as well as Laser Particle Sizer. The result indicates that ultrafine TiC powders with low impurities was prepared at temperature range 1490~1510℃ for a short time. The surface of TiC particles is homogeneous and loose agglomeration while the grain size (D50) is about 1-10μm. Lattice parameter calculation indicates that sub-stoichiometric TiCX (x<1) should exist in TiC powders when TiO2: C (molar ratio) =1:3. But stoichiometric TiC1.0 was prepared when TiO2: C (molar ratio) =1:4.
  • Effect of different surface desizing technologies on the bulk structure and surface structure of carbon fibers
    Min Zhang
    . 2010, 41(09): 40-0.
    Abstract ( ) Knowledge map Save
    Sizing agent on the surface of carbon fibers was removed by immersion in acetone, instant high-temperature treatment and high-temperature treatment in N2. The properties of carbon fibers with different desizing technologies were compared and investigated by field emission scanning electron microscope (FESEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), laser Raman spectra (LRS). The results show that three dezing technologies do not destroy the bulk structures of carbon fibers, but have different impact on the desizing of sizing agent on the surface of carbon fibers. The desizing effect of the immersion in acetone is not obvious; the instant high-temperature treatment can remove the sizing agent but also destroy the surface microstructure of carbon fibers. The high-temperature treatment in N2 can eliminate the residue of the pyrolytic products of sizing agent and prevent the damage of the surface properties of carbon fibers at high temperature. The high-temperature treatment in N2 is most effective to remove the surface sizing agent.
  • Characterization of LixMg0.2Zn0.8-xO quaternary alloy thin films prepared by Sol-gel
    LIU Feng Qiong;LIU Su
    . 2010, 41(09): 41-0.
    Abstract ( ) Knowledge map Save
    ZnO and LixMg0.2Zn0.8-xO quaternary alloy thin films were prepared on the glass by sol-gel method. The properties were examined by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Photoluminescence (PL), Van der Pauw method and Thermal probe. The results showed that the LixMg0.2Zn0.8-xO quaternary alloy films have the structural characteristics of ZnO thin films. Compared to the ZnO thin films, the crystalline, grain size and photoluminescence intensity of the LixMg0.2Zn0.8-xO quaternary alloy films were significantly increased. There are two peaks in the photoluminescence spectra of the LixMg0.2Zn0.8-xO quaternary alloy films, including the 380 nm - 390 nm UV peak and a stronger intensity of visible light-emitting. The wavelength of the UV peak decreased as the value of Mg/Zn is increased. The resistivity of the LixMg0.2Zn0.8-xO quaternary alloy decreases as the components of Li increases.
    • 综述
  • Influence of MnO2 materials on performance of spinel LiMn2O4 prepared by solid state method
    ;;
    . 2010, 41(09): 42-0.
    Abstract ( ) Knowledge map Save
    It has become an important topic to improve structural stability and electrochemical performance of spinel LiMn2O4 for lithium ion batteries. MnO2 is the most popular Mn source to synthesize spinel LiMn2O4, and its properties are one of the key factors for the performance of spinel LiMn2O4. In this paper, latest progress on MnO2 as Mn source was reviewed, and the influence of crystal structure, chemical composition and physical charater of MnO2 on physical and chemical performance of spinel LiMn2O4 materials was discussed. It was believed that it would be a breakthrough in improving structural stability and electrochemical performance of LiMn2O4 to optimize MnO2 with better characters.
    • 研究与开发
  • Preparation of MnO2/γ-Al2O3 Catalysts Modified by CeO2 and its Catalytic Oxidation of p-Nitrophenol Wastewater under Microwave
    ZANG Chuan Li;WANG Jin Ming
    . 2010, 41(09): 43-0.
    Abstract ( ) Knowledge map Save
    A series of MnO2/γ-Al2O3 catalysts modified by different amount of CeO2 were prepared by one-step impregnation-calcinations’ process，the optimal combination were calcined at different temperature of 350℃, 500℃, 700℃, by the time, XRD was used to identify their crystallites. The effect of the catalysts on degradation of the refractory p-Nitrophenol was investigated in a trickle bed reactor in microwave oven. The results showed that the crystal forms of catalysts calcinated at 350℃、500°C were amorphous，and 700℃ was Mn2O3.The highest removal rate of PNP was 92.9%, while the catalyst 15g with the CeO2 content was 4% and TOC of PNP was 3000mg/L, pH6，and its dropping rate was 3ml/min under 800W power of microwave. Addition of inhibitor on free radical (tert-butyl alcohol) showed that the oxidation process maybe followed the free radical reaction mechanism.
  • Optimization and Characterization ofinjected β-TCP CPC
    WANG Xiao Hong
    . 2010, 41(09): 44-0.
    Abstract ( ) Knowledge map Save
    Abstract: In this paper, self-made β-TCP powder used for solid phase of CPC. While the liquid phase was chitosan, citric acid and polyvinyl alcohol according to a certain percentage. The design orthogonal was tested to determine the best ratio of the system from the coagulation time and compressive strength of the CPC. And the impacts of various components to the coagulation time and compressive strength are analyzed. In addition, the cell culture was used to evaluate biocompatibility. Thus this synthesis CPC was potentially prepared injectable calcium phosphate bone cement to meet the clinical needs.
  • The effect of pressure on the electric transport properties of n-type CoSb2.750TexGe0.250-x skutterudite compounds
    yiping jiang ;;
    . 2010, 41(09): 45-0.
    Abstract ( ) Knowledge map Save
    In this letter, n-type skutterudite compounds of CoSb2.750TexGe0.250-x (x=0.125, 0.175, 0.200) were synthesized by high pressure and high temperature method. The effect of different pressure on the transport properties of CoSb2.750TexGe0.250-x was studied at room temperature. The electrical properties including the Seebeck coefficient and the electrical resistivity depending on the synthetic pressure were measured. The measurement results indicate that CoSb2.750TexGe0.250-x skutterudite compounds are n-type conduction. The absolute values of Seebeck coefficient and electrical resistivity for CoSb2.750TexGe0.250-x increase with an increase of the synthetic pressure and Te doped content. The highest power factor of 7.59 ?w/cm?K2 is obtained for CoSb2.750Te0.200Ge0.050 at 2GPa
  • Preparation of Ag/Zn Ions Implanted Stainless Steel for Antibacterial Applications
    ;
    . 2010, 41(09): 46-0.
    Abstract ( ) Knowledge map Save
    Antibacterial stainless steel has attracted much attention recently, with the development of the people’s living level and the increasing public awareness on hygiene during daily life. Antibacterial agents such as silver and zinc were the common components in antibacterial stainless steel. However, few reports concerned with two or more antibacterial agents in preparation for antibacterial stainless steel so far. To get antibacterial properties and enhanced corrosion resistance, stainless steel implanted by silver and zinc ions simultaneously was firstly reported in this paper with a metal vapor vacuum arc (MEVVA) source. Standard plate count method was employed to estimate antibacterial properties of Ag/Zn implanted stainless steel, which showed excellent antibacterial activities (>99%) against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Corrosion resistance was investigated by electrochemical potentiodynamic polarization. The results showed that corrosion resistance of stainless steel was slightly enhanced after Ag/Zn implantation. The implanted layer was characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). The Ag3d spectrum associated with metallic silver to silver oxide. And Zn2p spectrum associated with zinc oxide. The surface roughness decreased with the increasing of implantation dose. The relationship between the implantation dose and antibacterial activities was also discussed.
  • The research of the characteristic of local crystlline phases in Co-based amorphous ribbon with asymmreical loop
    Lei Zhou;;;jun he;
    . 2010, 41(09): 47-0.
    Abstract ( ) Knowledge map Save
    The hysteresis loops of the longitudinal field annealed Co58Fe5Ni10Si11B16 amorphous ribbons have an asymmetrical characteristic. This feature can be obtained at room temperature. Several factors about the formation of the phenomenon have been discussed by the experimental observation and simple phenomenological explanation. One of the significant factors, which can promote this behavior, is the magnetically harder crystalline phases grown in the amorphous matrix during annealing. Much attention was paid here to pursue a proper thermomagnetic process, which can provide a way to shift the loop of Co-based ribbons. The dependence of the microstructual characteristics of local crystalline phases on the annealing conditions was deeply studied. Based on this avenue, the Co-based ribbons with interesting asymmetrical magnetic feature can be manufactured for potential application.
  • The hydrophilic modification of sugar copolymer based on styrene/maleimide to PVDF membrane
    ;XU You Yi
    . 2010, 41(09): 48-0.
    Abstract ( ) Knowledge map Save
    The D-Glucoseamine was grafted to ultrahigh molecular weight poly(styrene-alt-maleic anhydride) via graft-to copolymerization method in solution. The structure and molecular weight of the resultant amphiphilic grafted copolymer SMA-g-GLA was characterized by 1H-NMR and GPC respectively. The SMA-g-GLA was blend with PVDF to fabricate blend membranes by the standard immersion precipitation phase inversion process. The surface and cross-section morphology of pure PVDF and blend PVDF membranes were characterized by SEM. The surface hydrophilicity of pure PVDF and blend PVDF membranes were characterized by static water contact angle. The anti-fouling property was characterized by BSA static absorb experiment.
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