25 March 2011, Volume 42 Issue 03
    

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    研究与开发
  • Morphological Control of CaCO3 Particles by double-hydrophilic block copolymers
    . 2011, 42(03): 1-0.
    Abstract ( ) Knowledge map Save
    Double-hydrophilic block copolymers, poly(N-vinylprrolidone)-block-poly(2- acrylamido-2-methyl-propanesulfonicacid)(PVP-b-PAMPS) and poly(N-vinylprrolidone)-block- poly(N,N-di-methylaminoethylmethacrylate) (PVP-b-PDMAEMA), were used to prepare CaCO3 for the regulation of mineralization and morphology of inorganic particles. The as-prepared products were characterized with scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results suggested that double hydrophilic block copolymers could control CaCO3 particles with unusual, well-defined morphologies. The morphology and particle size of the CaCO3 particles changed with the variation of pH. It was revealed that with increasing pH, the effect of the polymer on the crystal control strengthen, and the particle morphology generally varies from peanut-like (pH=11), silkworm chrysalis-like (pH=9), to step-multilayer assemblies (pH=6) in aqueous solution of PVP-b-PAMPS. The morphology of CaCO3 particles showed step-multilayer assemblies with smooth by using PVP-b-PDMAEMA as crystal growth modifiers.
  • Influence of Monomer Curing Characteristic on the Developing Density of light-thermal Sensitive Microcapsule
    ;;
    . 2011, 42(03): 2-0.
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    Abstract: The light-thermal sensitive microcapsule is synthesized by interfacial polymerization method, which can act as novel information recording material, and the capsule core is distinguished by the encapsulated monomer. The surface topography of unencapsulated core material UV-curing is studied by atomic force microscopy, and the monomer curing property in microcapsule is analyzed by infrared spectroscopy technology, and the developing density of light-thermal sensitive microcapsule is detected by thermal imaging technology. The results show that curing speed of different monomer mainly depended on the function groups and surface topography of curing product have related on the contents of unsaturated C=C bond in monomer. The curing speed of different monomer and cross-link density of curing product are the main factors effecting on the developing density of light- thermal sensitive microcapsule. Base on the experimental results, the effect of monomer on the developing density is ranked as: TMPTA>(PO3)TMPTA>DPGDA.
  • Preparation of polymerizable silica hybrid nanoparticles with tertiary amine structure and its curable properties
    ma guozhang
    . 2011, 42(03): 3-0.
    Abstract ( ) Knowledge map Save
    Abstract: Nanosilica was modified with 3-aminopropyltriethoxysilane, then reacted with trimethylopropane triacrylate to prepare polymerizable silica hybrid nanoparticles with tertiary amine moiety. Characterization of the modified nanosilica by FT-IR and TGA shows that the tertiary amine structural compound was grafted onto the nanosilica, the percentage of grafting for silica was more than 22.6%. Determination of conversion of C=C double bonds of coatings with silica hybrid nanoparticles discloses that the photopolymerization rate increased because oxygen inhibition was overcome by tertiary amine during curing process.
  • A study on the application of green surfactants to polyacrylate emulsion
    KaiBing HUANGQiao-Ling LIANG
    . 2011, 42(03): 4-0.
    Abstract ( ) Knowledge map Save
    A polyacrylate emulsion was prepared by pre-emulsified technique, adopting semi-continuous seeded emulsion polymerization methods. Choosing environmental friendly alcohol ethoxylates (AEO-9), sulfosuccinic acid alkyl polyoxyethylene monoester disodium salt (A-102) and sorbitan monooleate (Tween 80) instead of traditional alkyl phenol ethoxylates (APEO) as surfactants in polymerization. In this article, the effects of these surfactants on viscosity, residual monomer, molecular weight, stability, glass transition temperature with particle diameter of emulsion were explored. The results show that substitutions of APEO by green surfactants realize the ecological security of polymerization. In addition, the emulsion properties are excellent.
  • Fabrication of mullite-corundum porous ceramic membrane support
    . 2011, 42(03): 5-0.
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    Prepared by precipitation method with aluminium nitrate and ammonium acid carbonate, after calcining，superfine powder coated alumina was ball-mill mixed with nano-silica in a certain proportion, then pre-sintered, an appropriate amount binder and pore-forming agent were added. After kneading、aging、extrusion molding and drying, the membrane supports were temperature-programming sintered to certain temperature and held for 2h . It is shown that support body with 12 wt.% SiO2 and sintered at 1550℃ has much better comprehensive functions: water flux is 22.21 m3.m-2.h-1 ,the bursting strength is 3.40 MPa, and open porosity is 40.21% . After dipping in 10 wt.%H2SO4 or 5 wt.% NaOH for 36 h at 100℃ respectively, the membrane support still has a bursting high up to 2.67 MPa and 2.89 MPa，it indicates that the acid resistance and alkaline resistance property of the membrane support is excellent.
  • Study on the temperature dependent properties of detector-grade CdZnTe crystals
    Yadong Xu
    . 2011, 42(03): 6-0.
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    To evaluate the charge transport behaviors associated with the temperature variation, the pulse height spectra for CdZnTe crystals were obtained under various bias voltages, in the temperature range of 230-300 K, using an un-collimated 241Am α particles source with the energy of 5.48 MeV. It was demonstrated that the photo-peak positions were non-sensitive to the temperature for high quality CdZnTe crystals. In terms of CdZnTe crystal with de-trapping level defects, the charge drift velocity was significantly delayed due to the re-emission of charge carriers out of the traps. The pulse shapes shown distinct exponential decay component which enhanced as decreasing the temperature. 241Am @ 59.5 keV γ-ray spectroscopy response of CZT detector were obtained at room temperature and 280 K, respectively. In addition, the leakage current of the detector, under the electrical field strength of 1500 V/cm, were evaluated as a function of the temperature. The concentration of the charge carriers were reduced as decreasing the temperature, which resulted in the high bulk resistivity, decreased the leakage current, and therefore improved the energy resolution.
  • Fabrication and properties of Mg65Cu20Zn5Y10 porous metallic glass
    Tang xing;ZUO Xiao-qing
    . 2011, 42(03): 7-0.
    Abstract ( ) Knowledge map Save
    To improve the plasticity strain of Mg-based metallic glass, Mg65Cu20Zn5Y10 porous metallic glass was fabricated by water cooled copper mold casting – copper core drawing method. The structure, thermal stability and compressive property of the fabricated Mg65Cu20Zn5Y10 porous metallic glass were investigated. The results show that Mg65Cu20Zn5Y10 porous metallic glass with diameter 6mm and length 24mm was fabricated by using the multi-core water cooled copper mold. Compared with Mg-based metallic glass, pore structure has no influence on the thermal stability. 40% plastic strain of Mg65Cu20Zn5Y10 porous metallic glass had been achieved under a lower stress. As the fracture micro-morphology of Mg65Cu20Zn5Y10 porous metallic glass being vein pattern, the fracture of this porous metallic glass belongs to ductile fracture.
  • Enhanced electrical properties in Ce3+ and V5+ co-doped multiferroic BiFeO3 films
    . 2011, 42(03): 8-0.
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    Pure, Ce3+ and V5+ co-doped multiferroic BiFeO3 thin films, BiFeO3(BFO) and Bi0.97Ce0.03Fe1-xVxO3 (x=0, 0.01, 0.02, 0.03)(BCFVx), were successfully prepared on Pt/Ti/SiO2/Si substrates by Sol-gel technique. The structures and the surface morphologies measurements revealed a gradual phase transition from a rhombohedral to a pseudotetragonal structure and decreased grain sizes in the Ce and V co-doped BFO films. The dielectric property and leakage current density measurements indicated a large increase in the dielectric constanct and greatly decreases in the dielectric loss and the leakage current density in the Ce and V co-doped BFO films. Improved ferroelectric properties were obtained in the BCFVx films of x=0.01 with a well squared-shaped P-E hysteresis loop.
  • The Preparation and Property of a Poly(Lactic Acid) Biomaterial Modified by Biotin
    jiang wei min ;;
    . 2011, 42(03): 9-0.
    Abstract ( ) Knowledge map Save
    The aim of this research is to overcome the drawbacks of PLA in drug delivery system, which are short blood circulation time and non-active targeting. Based on PEG-graft-PLA (PPLA) developed in our lab, biotin was grafted onto PLA to produce BPLA by NHS-activated method. The ninhydrin coloration, 1H-NMR, DSC, water contact angle test, fluorescence labeled protein absorption test were used to characterize BPLA. Results from ninhydrin coloration, 1H-NMR, DSC, water contact angle test showed the biotin had been covalently grafted onto PPLA. Fluorescence labeling test demonstrated that the new BPLA had the property of decreasing the nonspecific protein (BSA) absorption and increasing specific protein absorption (Avidin) evidently compared with PPLA. It was predicted that BPLA could increase the blood circulation time, meanwhile can combine with its ligand-avidin through high affinity or combine with the biotionylated protein via avidin as arm, which may have the active targeting in drug delivery system.
  • Preparation and Characterization of Triazine dithiol and silane composite Nano-film on Aluminum alloy surface
    Fang Wang ;qian wang;junjun liu
    . 2011, 42(03): 10-0.
    Abstract ( ) Knowledge map Save
    Polymeric nano-films（PDB） are prepared by electrochemical polymerization of 6-N,N- dibutylamino-1,3,5-triazine-2,4-dithiol monosodium (DBN) on aluminum alloy surface. Then the PDB film is treated by silanization of hexadecyltrimethoxysilane to form the composite nano-films（CPDB）. The cyclic voltammetry curves were used to study the reaction and film growth process of PDB on aluminum alloy surface. The formation mechanism of CPDB film was also be analyzed and the film was characterized by means of FT-IR spectrometer, X-ray photoelectron spectroscopy, scanning electron microscope and contact angle. The results showed that the contact angle of aluminum alloy surface covered by PDB film was up to 124.3 °compared with 89.9° for blank aluminum alloy, and the contact angle of the sample covered by CPDB composite nano-film’s was 135.8 °. From SEM images and XPS spectroscopy on aluminum alloy surface, homogeneous and compact composite nano-films were obtained.
  • Synthesis of LiNi1/3Co1/3Al1/3O2 Cathode Material by Eutectic Molten Salt LiOH-LiNO3
    ;
    . 2011, 42(03): 11-0.
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    A lithium-ion battery cathode material, LiNi1/3Co1/3Al1/3O2, with excellent electrochemical properties was prepared via three-phase temperature sintering, using eutectic lithium salts (0.38LiOH.H2O-0.62LiNO3) mixed with the precursor Ni1/3Co1/3Al1/3(OH)2. This method was possessed of simple process and low cost, moreover, materials could mixed uniformly at the eutectic melting point without any grinding. The well-layered α-NaFeO2 structure was confirmed by X-ray diffraction (XRD). The ratio of characteristic diffraction peak I(003)/I(104) was high to 1.73. The charge-discharge test indicated synthesized powder showed an initial charge-discharge capacity of 156.4 mAh/g at a specific current of 0.2C at 55 oC in the rang 2.8～4.3 V up to 30 cycles with no noticeable capacity-fading (94.1% of the first discharge capacity), and the reversible capacity of 143.2 mAh/g and 127.9 mAh/g at a specific current of 1C and 2C charge-discharge rate.
  • Preparation and Photoluminescence Properties of a series of new colorized long afterglow materials
    . 2011, 42(03): 12-0.
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    A red long afterglow material which can be excited by visible light was prepared indirectly using red dye Rhodamine B which was mixed with the green long afterglow materials and could be excited by its afterglow. A series of colorized luminescent materials were prepared according to the trichromatic color theory. The afterglow spectra and the afterglow decay curves of these materials showed that with the changes of mixing ratios of the phosphors and dyes, the two characteristic peaks at about 510nm and 580nm have a little blue shift and red shift respectively, afterglow strength and color also have a regular variation. With the increase of rhodamine’s concentration, the samples’ overall brightness reduced, but the intensity of rhodamine’s red characteristic emission peak increased.
  • Characterization study on specific surface and absorption of CaTiO3
    . 2011, 42(03): 13-0.
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    Abstract: CaTiO3 was sintered in chamber type electric resistance furnace at 950℃, in order to research appropriate characterization of specific surface theoretical model and absorption, specific surface area of CaTiO3 was determined by nitrogen adsorption and characterized by Langmuir and BET theoretical model. The results show that Langmuir specific surface is larger than the BET specific surface, BET theoretical model with high precision was suitable to characterize specific surface of CaTiO3 by nitrogen adsorption; sintered CaTiO3 of nitrogen adsorption was multilayer adsorption.
  • Microstructure and Infiltration Principle of Ni- adulterated Ceramics/ Fe Alloy Composite Prepared By Pressureless Infiltration
    YANG Shao Feng
    . 2011, 42(03): 14-0.
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    Three-dimensional interconnected ceramics/ Fe alloy composites were produced by pressureless Fe alloy melt infiltration. The mainly process was that the mixture of Ni and Al2O3 powders was milled and then three-dimensional interconnected ceramics preforms were prepared by uniaxial pressing, and these preforms were sintered, lastly, pressureless infiltration process( the temperature was 1600℃ with 4h holding time) was carried out. The result shows that the interface between ceramics and Fe alloy reached a full homogeneity after infiltration and Fe alloy could infiltrate Al2O3 ceramic preforms and the maximum infiltration distance was more than 400 μm. Lastly, the infiltration principle was analysed using diffusion theory of liquid metals.
  • Corrosion behavior of Nd-Dy-Fe-Co-B magnets in different corrosive environments
    Li Jia-jie
    . 2011, 42(03): 15-0.
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    Corrosion behavior of sintered Nd-Fe-B magnets was investigated in steady-state damp heat (HH) and pressure cooker (PCT) climates. The macroscopic and microscopic corrosion morphologies were observed by DC and SEM. The effect of alloy composition and different corrosive environments on magnetic flux loss was discussed. It shows that the damp heat resistance of sintered Nd-Fe-B magnets can obviously improved by Dy substitution for Nd partially and minor Co addition. The corrosion product and their macroscopic and microscopic morphologies have distinct difference in HH and PCT climates. The corrosion rate in PCT is much slower than that in HH climate. It is probably because that high-pressure steam leads to an oxygen-deficient supply, and the steam/liquid film on the surfaces of magnets will hinder the diffusion of oxygen.
  • Effect of powder size on magnetic properties and microstructures of sintered 2:17-type SmCo magnet
    . 2011, 42(03): 16-0.
    Abstract ( ) Knowledge map Save
    Abstract: 2:17-type SmCo sintered permanent magnets with high remanence were prepared by powder metallurgy technology. The effect of average powder size D on their magnetic properties and microstructures has been investigated. With increasing the ball milling time from 30 to 80 min, the obtained average powder sizes decrease from 6.2 to 4.3μm. It is found that the average grain sizes of the corresponding final sintered magnets vary from about 80μm to 30μm, giving rise to the increasing of the content of oxygen significantly. Optimum magnetic properties occur for the sintered magnets when the D is located in the range of 5 - 6μm. In special, the best magnetic properties, Br=11.6kGs, Hcj>26kOe, and (BH)m=29.1MGOe were obtained at D=5.7μm.
  • Synthesis and Characterization of High Performance NaA Zeolite-Polyimide Composite Membrane
    wenhui yuan
    . 2011, 42(03): 17-0.
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    The NaA zeolite membrane was synthesized on porous α-Al2O3 disk support via microwave heating method. A dense intergrown NaA zeolite-polyimide (PI) composite membrane of about 10μm in thickness was prepared by dip-coating with polyamic acid solution and imidization process on the NaA zeolite membrane. The composite membrane was characterized by XRD, FT-IR, SEM and gas permeation tests. The differences on morphology，structure and gas permeability between NaA zeolite and NaA zeolite-PI composite membrane were analyzed. XRD results show that only NaA zeolite emerges on the support, and FT-IR results show that PI has been successfully synthesized on NaA zeolite membrane surface. The SEM images show that the particles are twinborn by well intergrowth on the composite membrane surface. Gas permeation tests on H2, O2, N2 and C3H8 under different temperatures display that the permeance of H2 on the NaA zeolite-PI composite membrane at 473 K is 7.86×10-8 mol/m2?s?Pa which is lower than that (8.21×10-8) of NaA zeolite membrane, and the permselectivity of H2/C3H8 on the NaA zeolite-PI composite membrane is 17.24, much higher than that (9.22) of NaA zeolite membrane.
  • Mechanism Simulation of Magnetorheologic Grease
    He Guotian ;
    . 2011, 42(03): 18-0.
    Abstract ( ) Knowledge map Save
    Magnetorheologic fluid becomes one of the important branches in the research of intelligent material. The sedimentation of magnetorheologic fluid is not well solved yet. Thus, a new kind of non-sedimentary magnetorheologic fluid-- magnetorheologic grease comes into being because of demand. This paper established the model of shear stress, and constructed body centered cubic pillars model based on the density of ferromagnetic particle to analysis the mechanism and characteristics of magnetorheologic grease. The general shear stress of magnetorheologic grease could express as the sum of the shear stress caused by viscose support liquid and grains, described the relationship between shear stress and magnetic strength and particle size, and the shearing force under zero field. Theoretical and experimental results agreed with each other, which certified the constructed model is feasible.
  • Parameter Optimization of Surface Activation on Silicon Wafer
    Lei NIE ;;;
    . 2011, 42(03): 19-0.
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    The effects of important process parameters in surface activation of monocrystal silicon wafer were investigated by orthogonal experiments and the activation process was optimized. The three parameters, volume ratio of activation solution, processing time and temperature, were selected as invetigation objects. Based on the characters of surface activateion process, the influences on surface activation of these parameters were estimated by the means of contact angle measurement expeiments and 30% salt water was the testing solution. The experimental results were analyzed which showed that among the three parameters, activation temperature had the most intimate relationship with surface activation result. And the volume ratio of activation solution had more obvious effect than processing time. This optimized process was used in silicon direct bonding and the results of bonding expriment indicated the void-free bonding could be realized by this process.
  • Microwave hydrothermal synthesis and characterization of self-assembled flower-like nickel hydroxide
    Zhen-Feng ZHU ;
    . 2011, 42(03): 20-0.
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    The Ni(OH)2 architectures with flower-like morphology assembled from nanosheets have been successfully synthesized through a microwave-assisted hydrothermal method using urea as a hydrolysis-controlling agent and polyethylene glycol (PEG) as a surfactant. The NiO architectures with similar morphology were obtained by a simple thermal decomposition process of the precursor Ni(OH)2. The as-obtained products were well characterized by XRD, TG-DTA, SEM, TEM, FTIR and UV-Vis. The experimental results shown that flower-like Ni(OH)2 architectures with a diameter of 2.5-4.0 μm are assembled from nanosheets with a thickness of 10-20 nm and width of 0.5-1.5 μm. The UV-Vis experimental results shown that the band gap of the as-synthesized NiO samples was about 3.27 eV, which shows obvious red-shift compared with that of the bulk NiO. The electrochemical performance of the Ni(OH)2 was investigated by means of the experiment of Cyclic Voltammetry. The results indicated that it was reversible.
  • Effect of hydrogen dilution on microstructure of nanocrystalline silicon thin films
    ;;;;
    . 2011, 42(03): 21-0.
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    Abstract: A series of hydrogenated nanosilicon films were prepared by inductively coupled plasmas (ICP) chemical vapor deposition technique from a mixture of SiH4 diluted in H2. A variety of techniques including Raman scattering, X-ray diffraction and infrared absorption were utilized to analyze the microstructure and bonding characteristic of the deposited films at different hydrogen dilution ratio. Results indicate that a rapid structural transformation from a mostly amorphous phase to comprehensive nanocrystal was attained at a relatively high H2 dilution ratio. With increasing hydrogen dilution ratio ,the crystalline fraction and grain size monotonically increase ， and nanosilicon grains present preferential growth along the (110)direction. The results of FTIR studies show that when increasing hydrogen dilution ratio, the total hydrogen incorporation decreases while the SiH2 bond increases significantly. These indicate that grain-boundary area ratio and atomic-H etching are increased . The analysis of optical absorption spectrum reflects that we have extracted the regulation of optical band gap of nanocrystalline silicon (nc-Si) thin films in the spectral range from 1.72ev to 1.84eV by tuning hydrogen dilution ratio.
  • Synthesis of CuO porous nanorods and their catalytic activity in the decomposition of potassium chlorate and peroxide
    ;
    . 2011, 42(03): 22-0.
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    Copper monoxide (CuO) porous nanorods of 100-200 nm in diameter and 2-3μm in length were successfully synthesized using a hydrothermal reaction method in the presence of urea. The products were characterized by SEM,TEM,FTIR,XRD and TG analysis techniques. The results of catalytic activity indicate that CuO nanocrystal promoted potassium chlorate and peroxide decomposition. When the ratio of H2O2 to CuO is 5 to 1, the decomposition of peroxide is perfect.
  • Preparation and the Photoluminescence Properties of SrMoO4 Powder Prepared by Chemical Solution Deposition
    . 2011, 42(03): 23-0.
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    Crystallized SrMoO4 powder has been synthesized via Chemical Solution Deposited processing, in which inorganic salt has been chosen as raw materials, aiding with the common organic solvent. The structure, morphologies, grain size and the photoluminescence properties of the prepared SrMoO4 powder have been tested by employing X-ray diffraction (XRD), scanning electron microscope (SEM) and fluorescence spectrophotometer. The analysis results indicate that the SrMoO4 powder possesses single tetragonal and near-ball morphologies. The crystalline grains are in the nanometer-micrometer scale, full growth and crystallized well. Excited under the UV light of 296±4 nm, the SrMoO4 powder show the blue-green luminescence (λem=470 nm), which belong to the intrinsic luminescence of the tungstate and molybdate with scheelite structure.
  • Effect of methanol treatment on structure and properties of dry spinning fibers of regenerated silk fibroin
    Jing-xin ZHU
    . 2011, 42(03): 24-0.
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    The dry spinning fibers of regenerated silk fibroin were treated with methanol aqueous solution. The results showed that methanol treatment affected the morphology, structure and mechanical properties of the regenerated fibers. Before methanol treatment, the as-spun fibers were transparent and glossy; after methanol treatment, the fibers exhibited a white color and showed banded features along the fiber axis, moreover, birefringence of the fibers could be observed obviously. The structure of the as-spun fibers changed from random-coil or silk I conformation to silk II conformation and the breaking intensity of the as-spun fibers were improved after methanol treatment. Compared with degummed silk fiber, the fibers treated with methanol had higher module, but the breaking elongation was lower, the fibers were still brittle.
  • Study on Stabilizing Contact Resistance of Electrically Conductive Adhesives by in-situ Replacement Method
    ; ;;;;
    . 2011, 42(03): 25-0.
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    the effects of two kinds of water- soluble silver salt (silver nitrate or silver acetate) on heating behaviors, bulk resistivity of ECAs and contact resistance of ECAs on tin surfaces under aging condition were investigated. The DSC results showed the addition of silver salt did not influence curing behaviors of ECAs. The bulk resistivity of ECAs with 2wt% silver nitrate or 1.5wt% silver acetate decreased 48.5% and 47.4% after damp heat aging 600h, respectively, but the control samples only decreased 27.3%. In addition, the contact resistance of ECAs with more than or equal to 1wt% silver nitrate or 0.5wt% silver acetate was stable on tin finish after damp heat age. XRD, XPS and SEM results indicated that under the aging condition, the silver salt was plated on tin surfaces by in-situ replacement reaction, forming a compact silver layer on the interface between ECA/tin, which eliminated the electrochemical potential difference with the silver fillers in ECAs and prevented the occurrence of galvanic corrosion. Thus, the stabilization of the contact resistance of ECAs was obtained.
  • Preparation of Fe3O4/Halloysite Nanotubes Composites and Aqueous Magnetic Fluid
    JIA Pei Nan
    . 2011, 42(03): 26-0.
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    Abstract: Magnetic Fe3O4 nanoparticles were deposited on the inner and outer surfaces of natural halloysite nanotubes (HNTs) by reduction co-precipitation method. By means of special nanotubal structures of HNTs, Fe3O4 nanoparticles were homogeneously dispersed on its surfaces with particle sizes distribution of 10-30 nm in diameter, in which aggregation of Fe3O4 nanoparticles was controlled effectively. Powder X-ray diffraction(XRD) results showed that Fe3O4/ HTNs composites were composed of Fe3O4 and halloysites phase structures, which were stabilized in different heat treatment temperature of 373K, 423K and 523K. Vibrating-sample magnetometer (VSM) confirmed the superparamagnetic of the Fe3O4/HTNs composites. Aqueous magnetic fluids with good dispersibility were obtained by chemical modification on the surfaces of Fe3O4/ HTNs composites.
  • Membrane-spraying Material with the Function of Ventilation and Water Retention
    . 2011, 42(03): 27-0.
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    This paper developed a new type technique of material which was used to plant grass and stabilize sands in desertification region.Take the OP-10,Vomit 20 and Vomit 80 to emulsify the discard vegetable oil,which can decompose completely,then carry on a hydrophobicity-modification towards the native soil from desertification region, in the end,mix with the grass seed for making into a stabilizing sands and planting grass material based on hydrophobicity-modified soil particles.According to the analyse of humidity evaporation, planting grass in the synthetic climate box, microstructure,thermoanalysis,aperture-aperture capacity to that material, the results show it has the function of ventilation and water retention and also performs well in the test of planting grass in the synthetic climate box which can imitate surroundings of the desert。The best proportion is that the hydrophobic component is 1:20 （mL∕mL） to water and 3:20 （mL∕g） to soil.
  • Effect of silane coupling agent on the properties of aqueous polyurethane
    . 2011, 42(03): 28-0.
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    A series of waterborne polyurethane modified by silane coupling agent were prepared with isophorone isocyanate as hard segment, polyether polyol as soft segment, trimethylol propane as crosslinking agent and 3-aminopropyltriethoxysilane(APTES) as end capping agent for polyurethane prepolymer. The films of waterborne polyurethane were prepared. Mechanical properties, water contact angle and water resistance of the films were measured. The particle size and distribution of the emulsion was tested by dynamic laser light scattering(DLS). FT-IR indicates that APTES reacted with -NCO of polyurethane. Thermogravimetry analysis indicates that modification of APTES for polyurethane increased thermal stability of polyurethane. It was found that tensile strength of modified polyurethane increased and the elongation at break decreased with increasing w(APTES), Water and solvent resistance increased. TEM manifested emulsion particles are spherical. DLS showed that particle size of emulsion increases with increasing w(APTES). Pencil hardness of modified polyurethane films can reach 2H, pendulum hardness is 0.73 and impact resistance meets GB/T1732-93.
  • High quality graphene sheets from PAN based carbon fibers prepared by method of ultrathin section
    . 2011, 42(03): 29-0.
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    In order to realize the large-scale production of graphene thin films, the method of ultrathin section has been carried out for T700 and T300 carbon fibers without having the characteristic of skin-core structure respectively, moreover the ultrathin section samples have been prepared, the thin films of BM1 came from T700 and the thin films of BM2 came from T300 respectively. The thin films obtained with different carbon fibers were characterized by HRTEM, XRD, Raman spectroscopy. It has been investigated that the network-graphene planes composed with carbon atoms were partly straight and partly twisted in the BM1 thin films when compared between BM1 films and BM2 films, the distance between the carbon atoms of network-graphene plane decreases, the stratum order design of graphene in BM1 films was denser and the arrangement must show a preferred orientation along the drawing direction, their consistency of the neighboring graphene based planes is better, moreover, the highest degree of ordering in the BM1 thin films was shown, the relative content of the forming SP2 hybridized orbit of carbon atoms in BM1 films was higher. it was verified that large-scale and high performance graphene based thin films could be prepared and produced.
  • Synthesis and properties of polyurethane-fluorinated acrylate hybrid emulsion as water and oil- repellency agent
    ;Yi-ding SHEN;Xiao-rui Li
    . 2011, 42(03): 30-0.
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    Novel cationic polyurethane-fluorinated acrylate(FPUA) hybrid emulsion was prepared with the copolymerization of fluorinated acrylate(FA),styrene(St) and butyl acrylate(BA) in the medium of cationic polyurethane(PU) emulsion. The structure and properties of the emulsion and latex of FPUA were characterized by FT-IR, contact angle measurements, submicron particle size analyzer and TEM respectively. The results show that only the FA content is beyond 20% ,FPUA can have good water and oil-repellency at the same time. The contact angle of water and CH2I2 on the FPUA(w(FA)=20%) film can achieved 110o and 86orespectively. The surface free energy of the FPUA(w(FA)=20%) film annealed at 30℃ is 14.64 mJ/m2 which decreased 78.65% in contrast with PU film. At the same time, the treatment of the films with high temperature can decrease the surface free energy by more than 17.69%. The results of submicron particle size analyzer and TEM indicate the particle of FPUA is bigger than PU emulsion and wider in particle size distribution. Mechanism of core-forming of FPUA hybrid emulsion is discussed at last.
  • Synthesis and properties of pH and temperature-sensitive P(DMAEMA-g-PEG) hydrogels
    chen ming qing
    . 2011, 42(03): 32-0.
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    A novel temperature and pH-sensitive graft copolymer hydrogel was synthesized by redox initiator free radical solution polymerization of 2-(N,N’-dimethylamino)ethyl methacrylate (DMAEMA) and polyethylene glycol(PEG) macromonomer. The obtained results show that the hydrogels have temperature and pH double sensitivities as well as swelling-shrinking reversibility. The phase transition temperature of these hydrogels is about 45℃. The addition of a small quantity of PEG macromonomer makes the hydrogel have high swelling ratio. But with the increasing amount of PEG macromonomer, the swelling ratio decreases. The hydrogels swell in acidic medium and shrink in alkaline medium. It was found that the hydrogels have porous structure by scanning electron microscopy.
  • GaN thick films Growth on Si(111) by Hydride Vapour Phase Epitaxy
    Huai-Yue YAN ;;
    . 2011, 42(03): 33-0.
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    C-plane GaN thick films have been successfully grown on Si(111) substrates with AlN as buffer layers by hydride vapour phase epitaxy (HVPE) system. Raman scattering, X-ray diffraction (XRD), and photoluminescence (PL) measurements are used to analyze the structure and properties of the GaN films. The results indicated that the structure of the film is hexagonal wurtzite, the biaxial stress of film is tensile and the value is 0.17 Gpa, the band edge emission of the GaN thick film is at 363.7 nm and no yellow luminescence bands are observed. The AlN buffer layers can effectively block the additional reaction between Si substrate and reactive gas during the GaN growth, and reduce the residual stress of the GaN thick film.
  • Preparation and specific capacity performance of micro/nano hierarchical porous urchin-like NiO
    Hai-Dong LIU;;
    . 2011, 42(03): 34-0.
    Abstract ( ) Knowledge map Save
    Micro/nano hierarchical porous urchin-like NiO were successfully prepared by using NiCl2?6H2O and CO(NH2)2 as starting materials via hydrothermal synthesis, followed by thermal treatment. The microstructure and morphology of the samples were studied by employing XRD, SEM, HRTEM and Nitrogen adsorption-desorption. The results showed that large quantity of nanowires of 30-40 nm in diameter self-assembled into an urchin-like NiO microsphere with nanopores of 5-20 nm on the surface. The BET surface area of the urchin-like NiO microsphere can reach maximum to 325.238 m2 g-1 while pore volume attains 0.338 cm3 g-1. Electrochemical specific capacity performance was investigated by means of charge-discharge measurement. The results indicated that micro/nano hierarchical porous urchin-like NiO delivered a large first discharge capacity of 1636.2 mA h g-1 in a voltage range from 0.5 V to 3.0 V at 0.1 C rate, which was much superior to that of the synthesized NiO nanoparticles (792.8 mA h g-1), and also higher than the other NiO materials reported in the literature.
  • Catalytic Effect of Supported Nanometer NiO on the Thermal Decomposition of Ammonium Perchlorate by DSC/TG-MS
    Ling-Hua TAN ; ;;
    . 2011, 42(03): 35-0.
    Abstract ( ) Knowledge map Save
    The nanometer NiO/MgO composite particles were prepared via impregnation method. The phase and morphology of NiO/MgO composite particles were characterized by X-ray diffraction, transmission electron microscopy and energy dispersive X-Ray spectroscopy. The catalytic effect of the nanometer NiO/MgO composite particles for thermal decomposition of ammonium perchlorate (AP) was investigated by DSC and TG-MS. The results show that the nanometer NiO/MgO composite particles have effective catalysis on the thermal decomposition of AP, which can make high-temperature decomposition peak value of AP decrease by 92.2℃ and apparent decomposition heat increase by 0.376kJ/g. The main gaseous products of thermal decomposition of AP were NH3, H2O, O2, N2O, NO and several chloride gas. The supporting effect of the nanometer MgO can effectively prevent the aggregation of NiO particles and increase the active sites. In the meanwhile, superoxide ion(O2-) and oxygenic ion(O-, O2-) on the surface of nanometer metal oxide can accelerate thermal decomposition of AP.
  • Applications of composite initiator used in aqueous deposited polymerization for polyacrylonitrile
    . 2011, 42(03): 36-0.
    Abstract ( ) Knowledge map Save
    Acrylonitrile and itaconic acid copolymer, which is used in carbon fiber, was synthesized by the continuous aqueous deposited polymerization using composite redox initiator. The effect of different composite initiator, monomer ratio, polymerization temperature and initiator ratio on the copolymerization were investigated. From the results, it showed that using ammonium persulfate and ammonium sulfite to be composite initiator, the copolymerization temperature was reduced by a third when the conversion rate remains the same. The composite initiator has a positive effect on the thermal performance of polymer.
  • Research on Production Process of Polymer electrolyte Tantalum Capacitors
    . 2011, 42(03): 37-0.
    Abstract ( ) Knowledge map Save
    This paper studied film-forming process of high frequency and low ESR organic chip solid - electrolyte tantalum capacitor employing PEDOT as a cathode material. Particularly, the influence of different polymerized temperatures, concentration of doping agent and solvent evaporated temperature on ESR of chip solid tantalum electrolytic capacitor was discussed. The results showed that desirable PEDOT film is achieved when polymerized temperature was about 0 to 10℃，concentration of doping agent was 3% and solvent evaporated temperature was 80 ℃. As a result, the obtained organic chip tantalum capacitor exhibit lower ESR and better frequency characteristic than conventional capacitor.
  • Preparation and　Study of N-doped Hollow Tio2 Nanoparticles
    WU Shi-shan ;QIAO Min ;CHEN Qiang ;SHEN Jian
    . 2011, 42(03): 38-0.
    Abstract ( ) Knowledge map Save
    The N-doped hollow TiO2 nanopaeticles were prepared by a simple method. The PS nanopaeticles, ammonia and triethanolamine were used as templates, catalyst and inhibitor, respectively, the PS/TiO2 (core/shell) nanocomposite particles were synthesized by sol-gel process. The effect of the amounts of ammonia, triethanolamine and tetrabutyl titanate on surface morphology and thickness of TiO2 shell were investigated, respectively. The surface of TiO2 shell at ammonia amounts of 6.00 g was rougher than that of TiO2 shell at ammonia amounts of 3.00 g. The surface of TiO2 shell under triethanolamine amounts of 0.20 g was smoother than that of TiO2 shell under ammonia amounts of 0.10 g. The thicknesses of TiO2 shell were 25 nm and 43 nm when amounts of tetrabutyl titanate were 1.00 g and 3.00 g, respectively. In this study, the triethanolamine was again used as N resource to prepare N-doped hollow TiO2 nanopaeticles through cacination process of the PS/TiO2 nanocomposite particles, and it had visible light response.
  • Stabilization of polyisobutylene in carbon black/TiO2 electrophoretic display dispersion system
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    . 2011, 42(03): 39-0.
    Abstract ( ) Knowledge map Save
    A kind of electrophoretic display dispersion liquid containing carbon black and titanium dioxide particles dispersed in tetrarchloroethylene was prepared, and stabilization of polyisobutylene in dispersion liquid system was studied. The results indicated that a stable electrophoretic particls dispersion system could be obtained when the weight of polyisobutylene is 12% , the content of electrophoretic particles in the dispersion liquid is 10.38%（w/w）. The average particle size in dispersion system almost have no change at 10℃~60℃. The device prepared with the dispersion liquid showed excellent display properties, it's the contrast is 26.3 and the response time is 520ms.
  • High Efficiency Red Phosphorescence Polymer Light-emitting Diodes Based on Polyfluorene as the Host
    . 2011, 42(03): 40-0.
    Abstract ( ) Knowledge map Save
    Series of devices have been made based on a poss end capped polyfluorene and poly (N vinylcarazole) (PVK) as the host, a red Ir complex as the guest. An efficiency of 5.48 cd/A was achieved, which surpassed that of device based on PVK as the host. The activity of PVK at the device based on PFO-poss as the host was also studied. We found PVK as the hole-transport layer also participate the process of energy exchange, which can raise the efficiency of the device
  • Study on phase transition of nano-SiO2 during Preparation
    . 2011, 42(03): 41-0.
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    Nano-SiO2 powder has been synthesized with two-step acid pretreatment method from rice husk. The nano-SiO2 is characterized by Scanning electron microscope (SEM), High-resolution transmission electron microscopy(HRTEM) and Energy-dispersive X-ray spectrometry (EDX). Research results demonstrate that the prepared samples are a kind of Amorphous nano-SiO2 When the calcination temperature is less than 570℃. As the calcination temperature increasing, SiO2 microcrystals come into being and SiO2 crystallization degree is increasing . The amorphous nano-SiO2 is translated into Crystalline nano-SiO2 with Column at calcination temperature 1080 ℃. And the reasons for its phase transition are discussed.
  • Simulation of hot deformation process for die-upset Nd-Fe-B magnets
    ZHAO Rui
    . 2011, 42(03): 42-0.
    Abstract ( ) Knowledge map Save
    Abstract： Melt-spun powders were hot compacted in vacuum and die-upset forged at different deformation temperature with different strain rates. By analyzing the relationship of stress and strain at different deformation temperature during die-upset forging process, deformation behavior of Nd-Fe-B magnets was studied and parameters for describing plastic deformation were obtained. In order to clearly understand the role of deformation process in grain-boundary sliding and anisotropic grain growth simulations of the die-upset process were performed using DEFORM-F3, a three-dimensional finite element method based deformation modeling software. Strains in different regions of a cylindrical Nd-Fe-B magnet at different stages of the die-upset process can be determined. Simulation results reveal that the effective strain increased with the increasing of deformation ratio and show a maximum value at the central region. However effective strain decreases in the both direction of thickness and radius due to friction between die-wall and magnet interface. The uniformity of effective strain improves with the increasing of deformation ratio. The measurements of magnetic properties and XRD show that magnetic performance and crystal alignment improve with the increasing of deformation ratio and indicate a saturation behavior at the deformation ratio of 75%. Simulation result is good agreement with the measurement of magnetic properties and XRD.
  • Study on controlling the distribution of bioactive apatite polycrystalline nucleuses on titanium surface
    Chun-Li WEI;
    . 2011, 42(03): 43-0.
    Abstract ( ) Knowledge map Save
    In order to accelerate the osseointegration speed between titanium implant and bone tissue, titanium substrates were treated by physical and chemical methods. The treated titanium substrates were immersed in a simulated body fluid (SBF) and proper density apatite polycrystalline nucleuses were formed by controlling mineralization process. The apatite polycrystalline nucleuses were observed by scanning electron microscope (SEM) to investigate surface morphology and size. Average grain size and space between grains were statistical. The pH value of simulated body fluid (SBF) was measured by precise acidimeter. Also formation condition and process were discussed. The results have verified certain distribution of apatite polycrystalline nucleuses, between which space between of grains is less than osteocytes dimension (10-30μm), were prepared on titanium surface by controlling titanium surface roughness and sodium hydroxide concentration and immersion time.
  • Preparation and Characterization of Polylactide-Itaconic anhydride Copolymer
    Yao-Yao ZHANG ;;;;
    . 2011, 42(03): 44-0.
    Abstract ( ) Knowledge map Save
    Abstract: In order to improve the hydrophilicity and increase the number of available reactive functional groups of polylactide (PLA), a new PLA-bassed materials（PLA-co-IT） was synthesized. Using the benzoyl peroxide as initiator, Methacrylic Anhydride modified PLA and itaconic anhydride were copolymerized in toluene. The grafting percentage of the copolymers was analyzed by the modified rhodamine-carboxyl interaction method, and structure of copolymers was characterized by infrared spectrum (IR) and 1H nuclear magnetic resonance spectrum (1H-NMR). The results showed that the grafting percentage was increased with the increasing of itaconic anhydride percenrage in reactants. The glass transition temperature and decomposition temperature of PLA-co-IT were higher than these of PLA.
  • Hydrogenation reaction of thiophene by magnesium-based hydrogen-storage materials
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    . 2011, 42(03): 46-0.
    Abstract ( ) Knowledge map Save
    The hydrogen-storage materials were prepared from magnesium by reactive ball-milling under hydrogen atmosphere with coal-based carbon as milling aid, and then the hydrogen-storage materials were utilized for the hydrogenation reaction of thiophene to convert into H2S with the hydrogen released from the materials at certain temperatures. It was shown that hydrogenation reaction of thiophene took place at the temperature lower than the initial dehydrogenation temperature of the hydrogen-storage materials determined by differential scanning calorimetry. When the dehydrogenation of hydrogen-storage materials coupled with the hydrogenation of thiophene at suitable temperatures, the production of H2S increased. After reaction, the MgH2 in the hydrogen-storage materials released hydrogen and the magnesium combined with sulfur to become into crystalline MgS. To add molybdenum into hydrogen-storage material was favor to the hydrogenation of thiophene.
  • Synthesis and property of negative thermal expansion material Sc2(WO4)3
    ZHU Jun-Jun
    . 2011, 42(03): 47-0.
    Abstract ( ) Knowledge map Save
    Negative thermal expansion material Sc2(WO4)3 powders were synthesized using step-by-step solid state reaction with scandium dioxide and tungsten trioxide as raw materials. The structure and morphology of the products were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) ，respectively. The thermodynamic property of the powders was characterized by thermo gravimetric and differential thermal analysis (TG-DSC).The thermal expansion coefficients of products were measured by X-ray diffraction at different temperatures with Powder X software and thermal dilatometer，respectively. The results show that the sample is Sc2(WO4)3 with high purity and orthorhombic structure. The particles have irregular morphology and the size is between 0.2~0.7μm. The powders have no phase transition and decomposition in the temperature range from room-temperature to 1200℃.The average thermal expansion coefficients of Sc2(WO4)3 are -1.9×10-6℃-1 and -5.6×10-6℃-1 in the temperature range of 30~800℃，respectively.
  • Synthesis and Application of Styrene Acrylic Emulision Containing Hydroxyl Modified by Water-dispersible Polyisocyanate
    . 2011, 42(03): 48-0.
    Abstract ( ) Knowledge map Save
    Styrene Acrylic Emulision was prepared from styrene,butyl-acrylate, N-methylolacrylamide and acrylamide using polyvinyl alcohol as dispersing agent. Water-dispersible Polyisocyanate was obtained from HDI trimer and MPEG500.The paper surface strength agent was prepared by the combination of the styrene acrylic emulision with water-dispersible polyisocyanate. .Moreover, the applied properties of the paper were measured as follows when the dosage of the strength agent was 1% and the dosage of water -dispersible polyisocyanate was 0.5%: ring crush index of paper increased by 23.4%, paper tensile strength increased by 34.0%, and tearing strength and picking velocity increased by 38.6% and 30.4% respectively, the sizing value reached 57s.
  • Preparation and Characterization of PAn-TiO2 Composite Film
    . 2011, 42(03): 49-0.
    Abstract ( ) Knowledge map Save
    PAn-TiO2 Composite Film is electrosynthesized on stainless steel in sulfuric acid media containing aniline and nano-TiO2 particles by cyclic voltammetry. The electrochemical properties and ingredient of composite film were characterized by means of cyclic voltammetry (CV), X-ray diffraction (XRD) and differential scanning caloricity (DSC). The results show that the composite between TiO2 and polyaniline in structure is achieved and the incorporation of TiO2 enhances electric and electrochemical performance of polyaniline film. In article,the method of measuring resistance by “layer cell” can be used to compare conductivity and the further studies on the structure of composite film may be based on the conclusion of the composite between TiO2 and polyaniline in structure.
  • Synthesis and electrochemical properties of spherical LiFePO4 with various particle sizes as cathode material for lithium batteries
    CAO Yin
    . 2011, 42(03): 50-0.
    Abstract ( ) Knowledge map Save
    Spherical FePO4 particles with various sizes were synthesized using controlled crystallization method, then LiFePO4 materials were prepared with FePO4 as precursor by carbothermal reduction method. The crystal structure, microstructure and electrochemical properties of samples were characterized by XRD, SEM and galvanostatically charge-discharge experiments, and the tap-densities of samples with different paticle sizes were measeured.The samples remained the spherical shape successfully and LiFePO4 with large size had a tap density reach to 2.03g/cm3 but poor electrochemical properties. The small size LiFePO4 had the best gravimetric capacity at different discharge rate, the discharge capacity is up to 160.6mAh/g at 0.1C. However, the volumetric capacity of the medium size LiFePO4 were relatively higher, which were 230.4 mAh/cm3 at 0.1C. Generally, spherical LiFePO4 with small size has better gravimetric capacity and the volumetric capacity of the medium size LiFePO4 is higher, we should choose spherical LiFePO4 with appropriate size according to practical situation.
  • Comparative Study on Strain Sensing Behavior for Electrically Conductive Fibers
    ;Jun-Pu WANG
    . 2011, 42(03): 51-0.
    Abstract ( ) Knowledge map Save
    This paper studied the sensing behaviors of three different flexible electrically conductive fibers, i.e. PPy (polypyrrole) coated PA6, Lycra and XLA fibers, under larger deformation. The coating processes were completed by chemical vapour deposition method. Their sensing behaviors were measured by an Instron mechanical testing system, while the variations of resistances were recorded at the same time. The cross sections of the fibers were observed by means of SEM (Scanning Electron Microscope) and the coating morphology were observed by SPM (Scanning Probe Microscope). The microscopic images of the surface morphology were obtained by a SEM with a mini material tester system, so as to analyze the mechanism of sensing behavior of the fibers. It is shown that the Lycra and XLA fibers possess good sensing behavior under larger deformation during both monotonic loading and cyclic loading.
  • Synchrotron radiation XAFS investigation on wood structure hierarchical porous ZnO
    ;;
    . 2011, 42(03): 52-0.
    Abstract ( ) Knowledge map Save
    Abstract: This paper describes in detail the micro-crystal structural parameters of ZnO derived from morph-genetic transformation technology by synchrotron radiation XAFS experiment and the datas fitting of FEFF calculation.The results showed that we indeed obtained ZnO products after morph-genetic transformation process, and the Zn-O distance of first shell of hierarchical porous ZnO was 1.986?, the second shell Zn-Zn distance was 3.240?,Meanwhile, the ZnO had good ordered crystal structure for the obtained small Debye -Waller factor（ss1=0.00346，ss2=0.00780), At the same time,it showed that the degree of the order of first neighbor O shell of the absorbing Zn atom was higher than that of the secondary nearest neighbor shell.
  • The properties of the ultra-high molecular weight polyethylene (UHMWPE) modified by surface metallization and diamond-like carbon (DLC) film deposition duplex treatment
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    . 2011, 42(03): 53-0.
    Abstract ( ) Knowledge map Save
    In this paper, ultra-high molecular weight polyethylene (UHMWPE) was modified by surface metallization and diamond-like carbon (DLC) film deposition duplex treatment to improve its wear resistance. Firstly titanium metal interlayer about 30nm was deposited on UHMWPE substrate by filtered cathodic vacuum arc (FCVA) technology to make UHMWPE metalliztion, then DLC film was deposited. The results indicated that the UHMWPE metallization can reduce UHMWPE surface charge accumulation during the DLC films deposition. As a result, the deposition rate, sp3 content, hardness and wear resistance of DLC films were increased.
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