28 February 2013, Volume 44 Issue 04
    

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    综述·进展
  • Investigation review of the properties of intermetallic compounds in lead-free solder joint in electronic packaging
    ZHU Yong-xin;LI Xiao-yan;XIAO Hui
    . 2013, 44(04): 457-462.
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    The intermetallic compound (IMC) play an important role in the electronic packaging，which is a sign of reliable bonding. Nevertheless, thicker IMC layers exert detrimental influence on the bonding reliability for its intrinsic brittleness. Hence, it is meaningful to probe the property of the IMC layers. In this study, technique for testing the IMC property were reviewed and some results were listed, which mainly consisted of the hardness, modulus, yield strength and coefficient of thermal expand, etc.
  • Research Progress and Development of Welding Porosity of Die-casting Magnesium Alloy
    YOU Guo-qiang;DU Juan;TAN Xia;WANG Xiang-jie
    . 2013, 44(04): 463-467.
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    The recent research status of welding porosity of die-casting magnesium alloy was reviewed, including the gas sources, formation mechanism, influencing factors and prevention measures of welding porosity, and the high gas contents in base metals was considered as the major factor of influencing porosity formation tendency by analyzing. Because of the high original gas content of die-casting magnesium alloy, the traditional measures of prevention and control of porosity play a very limited role, and metallurgical measures may be a possible solution to pore formation in die-casting magnesium alloys.
    • 研究·开发
  • Powder-Metallurgical Preparation and Biodegradation Property of Fe-Zn alloy
    WANG Wei-qiang;LU Shan;QI Min
    . 2013, 44(04): 468-470.
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    In this paper, a new biodegradable Fe-Zn alloy containing 15w% of Zinc was prepared by Mechanical Alloying-Spark Plasma Sintering with different ball-milling time. The microstructure and composition of the Fe-Zn alloy were investigated by XRD, SEM and EDS. The biodegradation property was evaluated by potentiodynamic polarization and weight loss testing under static immersion. The Fe-Zn alloy was found to be composed of Fe-Zn solid solution and a small quantity of ZnO particles and has better degradation property than pure Iron.
  • Grafting of PVA fiber by Silane Coupling Agent and the role of Increasing the wet strength of paper
    WANG Zhao-hui;SHEN Yi-ding;FEI Gui-qiang;WANG Hai-hua
    . 2013, 44(04): 471-475.
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    The water-soluble polyvinyl alcohol fiber (PVA) surface was modified by use of silane coupling agent. In addition, discussed the influence of the unmodified and modified PVA fiber content, the silane coupling agent addition on paper wet strength , Compared to KH-550 and KH-560 of the improving effect of paper wet strength. Our study indicated that PVA fibers modified with silane coupling agent were more effective to increase the paper strength, and significantly improve the problem of staining the trough or aggregation and dispersion in Water, The optimum condition for a satisfactory paper strength is as follow: silane coupling agent addition：16.6%，modified fiber content：20%. What’s more, Scanning electron microscopy (SEM)energy spectrum shows that the Si element appeared after modified.This show up that the branched chain containing silicon success grafted to fiber surface the changes of the form of fiber surface were observed by the scanning electron microscopy (SEM) and the pHotograpH of atomic force microscope (AFM) showed that the hydropHlic group of the PVA surface were taken place by hydropHbic epoxy.
  • Synthesis, characterization and osteoblasts proliferation of a novel biomimetic material based on MGF-Ct24E modified poly (D, L-lactic acid)
    LUO Jia;LI Yu-xiao;WANG Pin-pin;WANG Yuan-liang
    . 2013, 44(04): 476-479.
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    Mechano-growth factor (MGF) is one of the most important growth factors of bone regeneration. A novel biomimetic poly (D, L-lactic acid) (PDLLA) modification was designed and synthesized based on MGF-Ct24E grafted butanediamine modified PDLLA (DPLA). MGF-Ct24Es were grafted into the side chain of DPLA via a stable covalent amide bond by using dicyclohexylcarbodiimide (DCC) as the condensing agent to produce biomimetic DPLA materials (MGF-Ct24E-DPLA). Amino acid analyzer (AAA) and High Performance Liquid Chromatography (HPLC) were used to characterize the MGF-Ct24E-DPLA. The hydrophilicity of MGF-Ct24E-DPLA was evaluated by means of the water-uptake ratios and static water contact angle. Data revealed that the grafting efficiency of MGF-Ct24E was about 24.7%. MGF-Ct24E-MPLA had better hydrophilicity than DPLA. The osteoblasts behavior of proliferation, on glass, DPLA and MGF-Ct24E-DPLA films was investigated and the results indicated that the introduction of MGF-Ct24E could improve osteoblasts proliferation. The MGF-Ct24E-MPLA with higher bioactivity may have potential application for bone tissue engineering.
  • First-principles study on Electronic Structure and Optical Properties of Wurtzite ZnO Doped with Ca
    LIN Lin;ZHAO Chun-wang;YING Chun
    . 2013, 44(04): 480-482.
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    Electronic structures and optical properties of pure and Ca-doped wurtzite ZnO have been investigated by first-principles study. Our results show that the band gap of Ca-doped ZnO becomes wider as a function of Ca doping concentration. As a result, the optical properties of Ca-doped ZnO have been changed correspondingly.The statics dielectric function becomes smaller as the increasing of Ca doping concentration. Furthermore, new absorption peaks appear in the absorption spectrum and the imaginary part of dielectric function of the Ca-doped ZnO, respectively, and blue shift occurs to the absorption edge, as compared with the pure ZnO.
  • The influence of depositing temperature on structure, corrosion resistance and mechanical properties of magnetron sputtered Ni3Al-Cr thin films
    XING Yong-yan;WEI Xian-hua;MA Yong-jun;DAI Bo
    . 2013, 44(04): 483-487.
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    Ni3Al-Cr thin films were deposited at 300℃、400℃、500℃, and 600℃ by magnetron sputtering. X-ray diffraction (XRD) and atomic force microscope were used to analysis the microstructure, and the surface morphology. The method that adopting four probe to measure the sheet resistance change during corrosion was used to analysis the corrosion resistance of the thin films. The hardness was measured by a nano indenter. The results demonstrated that the depositing temperature has much influence on microstructure, corrosion resistance, and mechanical properties. As depositing temperature increased, the crystalline size and particle size increased. Dense spherical particles were formed at 400℃ and 500℃. Unconsolidated cubic particles were formed at 300℃. Part particles grew excessively at 600℃. The thin film deposited at 400℃ had the best corrosion resistance and mechanical properties. Besides this, this study proved the sheet resistance method to be reliable to analysis the corrosion resistance.
  • Effect of vinyl concentration on the characteristics of silicone rubber vulcanization
    LIU Yan-wei;LU Ai;DENG Zhi-hua;SHI Dong-lin;LI Jing-li
    . 2013, 44(04): 488-492.
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    The vulcanizing characteristics and kinetics of silicone rubber have been investigated by a dynamic mechanical thermal analyzer called RSA3. The effects of vinyl concentration and temperature on the vulcanizing characteristics and kinetics of silicone rubber have been discussed. At the same time, the vulcanizing thermodynamics of silicone rubber has also been studied by using differential scanning calorimeter (DSC). The results indicate that，the crosslink density increases with the increasing vinyl concentration, and the storage modulus presents an uptrend. The mechanical properties are also improved largely due to the high crosslink density. Concluded from the results, the process of the vulcanization can be treated as two stages expressed in two ?rst-order kinetics equations, and the activation energy can also be figured out with Arrhenius equation. The activation energy decreases with the increasing vinyl concentration of silicone rubber.
  • In vivo study on polyurethane/nano-hydroxyapatitie/polyamid66 femoral condyle for reparing articular osteochondral defects for femur in dog
    SU Bao;LI Ji-dong;JIANG Dian-ming;LI Yu-bao;QIAO Bo;LI Wei-chao
    . 2013, 44(04): 493-497.
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    The PU/n-HA/PA66 femoral condyle was prepared. Material surface was observed with scanning electron microscope and the porosity was measured. The PU/n-HA/PA66 femoral condyle and the autologous femoral condyle were implanted into the distal femur and the articular cartilage and subchondral bone defects were repaired with PU/n-HA/PA66 femoral condyle and autologous femoral condyle separately. Gross examination, histological staining, collagen Ⅰ immunohistochemical staining，CT examination, blood routine and serum biochemical index and histological staining of the liver, kidney and spleen were conducted 24 weeks after operation. The porosity of the composite was 80.89%±5.01% and main pore size reached from 300μm to 800μm.The activity of dogs was normal and the cut healed well in both groups after operation. CT examination，histological investigation and immunohistochemical staining showed the two kinds of condylar prosthesises were closely combined with autologous bone in all the experiment animals. Trabecular bone in the pores of the biological femoral condyle became more and more and calcified gradually into mature bony tissue. The expression of collagen I of newly formed bone in the pores of materials was positive. The blood routine and serum biochemical index were both normal except the level of alkaline phosphatase increased[(62.67±24.04)U/L] after operation. Histological staining of the liver, kidney and spleen was normal 24 weeks after operation. PU/n-HA/PA66 femoral condyle has good internal bone defects repairing ability, cartilage substitution ability and biocompatibility, which is suitable for orthopedic biomaterials.
  • Spinel LiMn2O4 Prapared by Gel-Combustion Method
    LI You-kun;QIU Ke-hui
    . 2013, 44(04): 498-501.
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    Abstract：The precursor was prepared by sol-gel method using LiNO3，Mn(NO3)2 and citic acid monohydrate as the starting materials. The precursor was combusted in air，and then calcined at 600~ 900℃ for the certain times，so the LiMn2O4 with a type of the spinel crystal structure, space group Fd3m, was obtained. The phase transition of the precursor during heat treatment process was caracteristed by TG/DTA. The phase composition and the crystal structure of the LiMn2O4 were investigated by XRD (X-ray diffraction) patterns. The morphogenesis and the crystal particle size of the LiMn2O4 were observed by scanning electron microscopy (SEM). The effects of calcined temperature, heat treatment time and the molar ratio of Li to Mn（nLi/nMn）R on the phase composition，crystal structure and micro-morphology of the samples were researched. The optimal conditions obtained high pure LiMn2O4 sample are the calcination at 800℃ for 10h with the R=1.1/2.
  • Preparation of Lignocellulose-g-Acrylic Acid/ Montmorillonite Hydrogels and Its Adsorption
    SHI Yan-ru;XUE Zhen-hua;WANG Xi-ming;WANG Li;WANG Ai-qin
    . 2013, 44(04): 502-506.
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    Lignocellulose-g-acrylic acid/Montmorillonite (LNC-g-AA/MMT) hydrogels with three-dimensional cross-linked polymeric networks were prepared by a in situ intercalative polymerization technique. The effects of the mass ratio of acrylic acid to Lignocellulose-g-acrylic acid/Montmorillonite (LNC-g-AA/MMT) hydrogels with three-dimensional cross-linked polymeric networks were prepared by a in situ intercalative polymerization technique. The effects of the mass ratio of acrylic acid to lignocellulose, acrylic acid monomer concentration, neutralization degree, initiator and crosslinking agents of superabsorbent composites were explored. The adsorption capacity of LNC-g-AA/MMT was 1994.38 mg/g. And the desorption of MB onto the LNC-g-AA/MMT was experimentally determined, the desorption efficiency of LNC-g-AA/MMT was to 83.4%. The structure of the samples were characterized by XRD、TEM and TG. The results show that lignocellulose-g-acrylic acid intercalates into montmorillonite interlayer via destroying the crystalline structure of montmorillonite, and the exfoliated structure is formed in LNC-g-AA/MMT with better thermal stability.
  • Synthesis and photocatalytic activity of reticular Bi2O3 photocatalysts
    MA Zhan-ying;YAO Bing-hua;HE Yang-qing;BAI Hai-ni;GAO Yi-hong
    . 2013, 44(04): 507-511.
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    The reticular Bi2O3 photocatalysts were synthesized via cotton-template and heat treatment process. XRD, SEM, TGA, UV-Vis diffusion spectra were employed to characterize the phase structure, morphology, thermal stability and optical absorption properties of the samples. Results indicated that cotton played an important role in the formation of reticular structure. The flat Bi2O3 reticles with different diameter were staggered and overlapped, thus reticular Bi2O3 were formed. Using the degradation of MB as a model reaction, the photocatalytic and recycling properties of the reticular Bi2O3 were compared with Bi2O3 powders. Results indicated that the reticular structure materials showed better photocatalytic properties than Bi2O3 powders. The decolorization efficiency of MB solution reached about 93% at irradiation time 100 min and remained above 85% upon repetition (4 times). In addition, the formation mechanism of reticular Bi2O3 was discussed in detail.
  • Synthesis and properties of thermosensitive linear copolymer of P(NIPA-co-EA）
    XIE Sha-sha ZHANG Yi;KE Yu;ZUO Qin-hua;ZHONG Da-gen;LU Jian-bo;HUANG Yue-xin;XUE Wei
    . 2013, 44(04): 512-516.
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    A novel therosensitive copolymer P(NIPA-co-EA) was synthesized based on the monomer of N-isopropylacrylamide (NIPA) and N-ethylacrylamide (EA). 1H-NMR spectra, IR and GPC were employed to characterize the structure of the polymer. The LCST value of P(NIPA-co-EA) was adjusted by the component ratio of the two monomers and measured by turbidity and spectrophotometer methods. Moreover, the influence of additives to the LCST value of linear copolymer P(NIPA-co-EA), NaCl and BSA were studied. The results indicated that the LSCT value of copolymer P(NIPA-co-EA) was increased along with the increasing of molar ratio of EA monomer and it could be adjusted between 32.0-41.6℃. When the amount of NaCl was changed from 0.9 wt% to 2 wt% and added into P(NIPA-co-EA) solution, the LCST value of copolymer P(NIPA-co-EA) was decreased from 34.3℃ to 31.6℃. However, the increased concentration of BSA adding into P(NIPA-co-EA) solution made the LCST valued rised. What’s more, when 20 mg/mL BSA was added into EA10 solution, the LCST value of copolymer P(NIPA-co-EA) could up to 38.9℃.
  • Effects on the Bioactivity of TiO2 Nanotube Size
    WANG Xiao-hong;CAO Yang;LIU Zhong-xin;LI Shi-pu;LIN Shi-wei
    . 2013, 44(04): 517-521.
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    High order TiO2 nanotubes was prepared in glycerol solution as electrolyte by anodic oxidation. The differences of biological activity were studied of the different sizes of TiO2 nanotubes. The samples were soaked in simulated body fluid (SBF) to observe the deposition of hydroxyapatite and explored the biocompatibility by cell cytotoxicity experiments in vitro. Experimental results showed TiO2 nanotubes had different diameter and tube length under different anodic oxidation voltage. With anodizing voltage increasing the nanotubes showed increasing wall and diameter. The samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), etc. Hydrophilicity deposition, MG63 cell adhesion, and other biological evaluation were observed. The conclusion showed the samples showed the better biological activity with the increasing nanotube length and diameter of TiO2 nanotubes.
  • Theoretic and experimental study of Chain-formation mechanism for MRF
    HE Jie;GAO Li-xia;LONG Zheng;LIU Yong-zhi;LIU Xiu-mei
    . 2013, 44(04): 522-526.
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    Comprehensive theoretical and experimental analyses of chain-formation process for MRF are performed in this paper. Firstly, the physical model for the chain-formation process has been established. The Monte Carlo method has been used to simulate the chain-formation process under the gradient magnetic field. Secondly, we study the chain-formation process of magnetorheological fluid under the magnetic field by experiment. Numerical and experimental studies show that: when the magnetic field direction is parallel to the level of magnetorheological fluid and the external magnetic field is zero, magnetic particles are disordered. When the magnetic field strength increases gradually, the magnetic particles form smaller chains ,mesh and even columnar structure along the direction of magnetic field; When there is a certain angle between the magnetic field direction and magnetorheological fluid level, with the increase of magnetic field, in the vertical direction of the level, magnetic particles form the small chains and then become the large chains along the magnetic field, finally, all are in the arrangement of chains or columnar chain. The results of this study for magnetic rheological liquid preparation and magnetorheological fluid rheological study provides a theoretical basis.
  • Synthesis and Characterization of Hyperbranched Collagen Fiber Absorbent
    WANG Xue-chuan;ZHANG Fei-fei;QIANG Tao-tao
    . 2013, 44(04): 527-531.
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    Cr (Ⅵ) is one of contaminants in the industrial wastewater under strict control of pollution. This study used glutaraldehyde as crosslinking agent to graft hyperbranched polyamide amine(HPBN) onto collagen fiber(CF) to prepare hyperbranched collagen fiber absorbent(CF-HBPN). The influence of different conditions on the treatment effect was studied by the amino group content of CF-HBPN. IR, DSC-TGA, SEM-EDS were used to characterized the structure of product. The experimental results indicated that the optimum reaction conditions on the preparation of absorbent were the quality ratio of collagen fiber and HBPN was 1:0.7, the dosage of crosslinking agent was 0.533mL/gCF, the temperature was 40℃, 4h. Under these conditions, the amino content of CF-HBPN was 3.27 times higher than that of CF. Moreover, the absorbent prepared under these conditions was used in the treatment of solution contain Cr(VI), the removal rate was 99.57%.
  • Research on Microstructure and Electrochemical Properties of AlxFeCoNiCrTi (x=0.25, 0.5, 1.0) High-Entropy Alloys
    NIU Xue-lian;WANG Li-jiu;SUN Dan;Julius Jellinek
    . 2013, 44(04): 532-535.
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    The microstructure of AlxFeCoCrNiCu (x=0.25, 0.5, 1) with different Al content have been studied. Their electrochemical properties are compared with 304 stainless steel and AlxFeCoCrNiCu high-entropy alloys. The results show that the structure of prepared high-entropy alloy is gradually changed from a single FCC phase to FCC phase and BCC phase with the addition of Al. With the addition of aluminum from x=0.25 to 1.0, the hardness of the alloys increase from 165 to 485 HV Correspondingly. The polarization curves show that alloys has the better corrosion resistance than 304 stainless steel in 0.5 mol/L H2SO4 solution and 1 mol/L NaCl solution, and meanwhile Al0.5FeCoCrNiCu high-entropy alloy has the best comprehensive corrosion resistance.
  • The Study of Zn2+/Ag+ compound inorganic Antisepticwith Sepiolite as the carrier
    LIU Jing;LU Yu;YANG Fei;YU Min
    . 2013, 44(04): 536-539.
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    Aiming at the problem that sliver ion-contained inorganic antibacterial agent is subjected to discoloration, a technique for preparing dual-ion inorganic antibacterial agent is studied, in which the sepiolite is taken as a carrier, and the silver ion (Ag+) and the zinc ion (Zn2+) are taken as antibacterial constituents. Through detecting the content of antibacterial irons carried by the sepiolite by using the atomic absorption spectrum, the study on the technological conditions for the sepiolite to adsorb the Ag+ and the Zn2+ is carried out, and the testing and the observation for the antibacterial performance and the discoloration resistance of prepared silver-zinc/sepiolite are carried out. It is proven that: under the experimental conditions, when the mol ratio of the initial concentration of the Zn2+ to the initial concentration of the Ag+ in an adsorption solution is 10: 1, the mass ratio of the two antibacterial ions carried by the sepiolite is over 10: 1, so that the aim of increasing the content of the Zn2+ carried by the sepiolite and reducing the content of carried Ag+ is achieved. The prepared silver-zinc/sepiolite has excellent antibacterial performance and discoloration resistance.
  • Synthesis and photoluminescent characteristics of 8-hydroxy-2-methylquinoline gallium
    SUN Chun-yan;LIU Xu-guang;TAO Peng;CHEN Liu-qing
    . 2013, 44(04): 540-543.
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    8-Hydroxy-2-methylquinoline gallium(Ga(mhq)3) was synthesized, and its molecular structure was characterized by FT-IR spectrometry and 1H NMR techniques. Its optical gap and photocurrent properties were investigated by UV-vis absorption spectrometry, cyclic voltammetry, fluorescent emission spectrometry and electroluminescent spectrometry. Experimental results show that its optical gap is about 3.10 eV, as determined from its UV-vis absorption edge. Its UV absorption bands were at 259 and 365 nm. Ga(mhq)3 emitted intensive blue-green fluorescence at peak wavelength of 496 and 472 nm in THF solution and powder state, respectively. Finally, devices using Ga(mhq)3 as the emissive layer were fabricated and investigated. The device A with configuration of ITO/NPB(50nm)/Ga(mhq)3(30nm)/LiF(1nm)/Al(100nm) showed maximum emission peak at 508 nm and the maximum brightness of 901.5 cd/m2, after optimization by introducing electron-transporting material Alq3, brightness can reach 4339 cd/m2.
  • Numerical Simulation of High-temperature Carbonized Ablation Processes for Thermal Protective Composites
    YANG De-jun;LI Xu-dong
    . 2013, 44(04): 544-547.
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    In order to reveal the detailed thermal response of thermal protective composites under high temperature, the carbonized ablation process of composite materials is achieved through the method of finite element numerical simulation. Established a thermal composite finite element model for numerical analysis of ablation process of carbide primarily include internal pyrolysis, material quality loss, heat transfer modeling, carbon coating on the surface of erosion models, and the ablation process of carbon-phenolic composites is numerical simulated. Results show that ablation of the material is the result of combination of a variety of factors, with the ablation time increases, material internal pyrolysis reaction occurs, and the occurrence of layered phenomenon causing the materials been divided into carbide layer, pyrolytic layer and original material layer and the material layer moving over time to the inside material. The wall temperature decreases with the increase of the ablation volume of the material, and the carbonation ablation of materials has played an effective thermal protective effect. The results of numerical simulation meet the requirements of the research program. The research method is applicable for any carbide ablative thermal protection materials.
  • Preparation and characterization of binary fatty acid/SiO2 composite phase change energy storage material
    FU Lu-jun;DONG Fa-qin;YANG Yu-shan;HE Ping
    . 2013, 44(04): 548-551.
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    In order to prepare shape-stabilized phase change energy storage materials which were applied to control temperature of building materials, capric acid was mixed separately with lauric acid, myristic acid and palmitic acid to prepare binary fatty acid eutectic mixtures. The phase transition temperature of binary fatty acid and its corresponding mixing proportion are calculated based on Schroder equation. Shape-stabilized CA-MA/SiO2 composite phase change materials were prepared using sol-gel methods. The structure, microstructure, thermal properties and thermal stability of composite materials were characterized by infrared spectroscope, scanning electronic microscope, differential scanning calorimeter and thermogravimetric analysis apparatus, respectively. It was shown that as prepared binary fatty acid had an appropriate temperature and latent heat which can be applied in building field. The CA-MA was well dispersed in the porous network of SiO2, and there was no chemical interaction between CA-MA and SiO2. The melting temperature and melting latent heat of the composite phase change materials is 20.96 ℃ and 70.17 J/g, respectively, and composite materials have good thermal stability. So the composite materials were considered as an effective latent heat thermal energy storage materials in building energy conservation.
  • Thermoelectric properties of a chalcopyrite compound CuGaTe2
    LI Ya-peng;MENG Qing-sen;ZHOU Hong;YANG Jiang-feng;CUI Jiao-lin
    . 2013, 44(04): 552-554.
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    Abstract: Here we synthesized a Ga2Te3based chalcopyrite compound CuGaTe2 by spark plasma sintering technique. The XRD analysis indicates that the compound is a single phase CuGaTe2 with the band gap (Eg) of 1.0eV, which is much narrowed compared to that of intrinsic Ga2Te3 (1.65eV). The bandgap narrowing is directly responsible for the remarkable improvement of the electrical conductivity of the titled compound that exhibits 1.6×104-1m-1 at 701K. The lattice part dominates the total thermal conductivity that decreases sharply from 3.64 W.m-1.K-1 at room temperature to 1.1W.m-1.K-1 at 701K, almost obeying a T-1 relation, suggesting a dominant Umklapp process. The maximum thermoelectric figure of merit is 0.49 at 701 K, whereas that of Ga2Te3 is 0.16 at 860 K.
  • SYNTHESIS AND PHOTOELECTRIC PROPERTIES OF A SERIESOF POLY(BENZOBISOXAZOLE)S
    CUI Tian-fang;JIANG Jun-qiang;WANG Xiao-dan
    . 2013, 44(04): 555-558.
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    A series of poly(benzobisoxazole)s,including poly(p-phenylene-benzobisoxazole)(PBO), poly(1,4-naphthalene benzobisoxazole) (1,4-PNBO), poly(2,6-naphthalene benzobisoxazole)(2,6-PNBO), poly(2,5-thiophene benzobisoxazole)(PTBO), poly-4,4′-(1,2-diphynylethylene benzobisoxazole)(4,4′-PDPEBO) and poly(2,6-diylvinylene benzobisoxazole)(PBOV), were synthesized by polycondensation of 4,6-diamino-1,3-benzenediol dihydrochloride with terephthalic acid, 1,4-naphthalene dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,5-thiophenedicarboxylic acid, 4,4′-(1,2-diphynylethylene) dicarboxylic acid and 2,6-diylvinylenedicarboxylic acid respectively in polyphosphoric acid. The relationship between the resulting polymer chain structures and the properties of the polybenzobisoxazoles was also investigated.The results show that the target polymers were successfully synthesized characterized by Fourier transform infrared spectra and elemental analysis. The relationship between the structure and properties of poly( benzobisoxazole)s was analyzed using the conductivity meter and fluorescence spectrometer. The results of the study show that, the conductivity of PBO,1,4-PNBO，2, 6-PNBO，4, 4′-PDPEBO，PTBO, PBOV decreased in turn, and the data of PBO was 37.8 ms/cm, the conductive mechanism of polymer is mainly through the delocalization of the electrons in polymer molecules. π electron clouds can flow between the adjacent carbon atoms, but the electric conductivity is lower when conjugate chain become longer to some extent; In addition,the shape of poly(benzobisoxazole)s of fluorescence emission spectrum and stimulate spectrum are very similar, the biggest emission peak wavelength of poly(benzobisoxazole)s are almost consistent, and among them the fluorescence intensity of 2,6-PNBO is the strongest.
  • Spiral Molecular Cluster of Ni-Zn-Fe hydroxide Precursor
    YANG Di-lun;LI Zong-bao;ZENG Neng;YANG Lin;ZHOU Yun-bin
    . 2013, 44(04): 559-561.
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    Abstract: Ni-Zn-Fe hydroxide as a precursor was prepared using the coprecipitation of aqueous solution of mole ratio Ni2+: Zn2+: Fe3+=0.6:0.4:2.0 with OH- in gas bubble liquid membrane. The precursor was characterized by means of elemental analysis, EDS, FTIR, HRTEM, VSM, DSC and XRD. The precursor showed a five phase mixture of 0.6Ni(OH)2(H2O)0.75, (0.4-n)Zn(OH)2, (2-2m-2n)Fe(OH)3, mFe2O3 and nZnFe2O4 by XRD pattern. The microstructure of the precursor shows a large amount of spiral molecular clusters with 2-8nm size, a few of subcrystalline structures with about 10nm size and some disorder point contrasts around the molecular clusters and subcrystalline structures. The precursor can dehydrate slowly at room temperature into Fe2O3, ZnO and water. Fe2O3 and ZnFe2O4 subcrystalline structure were detected from the fresh precursor, which implied that spiral molecular clusters evolve by Fe(OH)3 preferentially dehydrates into Fe2O3 crystal nucleus, Zn(OH)2 dehydrates into ZnO, followed by nascent ZnO molecule self-assembles to Fe2O3 crystal nucleus into ZnFe2O4 subcrystalline structure, during the precursor was prepared. The magnetic property for the precursor was attributed to the presences of Fe2O3 and ZnFe2O4 ferrite both.
    • 工艺 ·技术
  • Preparation and electrochemical properties of polyaniline nanofibers/graphene composite
    WEI Cong-jie;DUAN Fang;NI Zhong-bin;LI Xiao-ting;CHEN Ming-qing
    . 2013, 44(04): 562-565.
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    A composite of graphene oxide (GO) and polyaniline (PANI) nanofibers was prepared by interfacial polymerization of aniline monomer using graphene oxide as substrates. The obtained PANI/graphene oxide composite was reduced to give the PANI nanofibers /graphene composite (PANI/GR) using hydrazine followed by reoxidation of ammonium peroxydisulfate (APS). The morphology and structure of the composites were characterized by FTIR, UV-VIS, XRD, SEM and TEM. It was found that the GO provided the substrates for polymerization of aniline, meanwhile had a doping effect on PANI. The “sandwich” structure composite was obtained in which the PANI fibers were between the graphene sheets. It exhibited the double-layer capacitor as well as Faraday pseudocapacitor charateristics, the highest specific capacitance of 460 F/g at a current density of 400mA/g due to synergistic effect between the two components, by cyclic voltammetry and galvanostatic charge-discharge analysis. The product shows a good electrochemical activity.
  • Study on preparation and properties of temperature-sensitive terpolymer microgels
    TANG Yi-qiang;SHI Dong-jian;NI Zhong-bin;HE Bing-xiao CHEN Ming-qing
    . 2013, 44(04): 566-568.
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    A series of novel terpolymer microgels were synthesized by surfactant-free emulsion polymerization of N-isopropylacrylamide (NIPAM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and N-tert-butylacrylamide (NTBA) using N,N-methylenebisacrylamide(MBA) as crosslinker in the presence of ammonium persulfate (APS) as initiator. The results showed that the terpolymer microgels had spherical structure and particle size was uniform based on the analysis of transmission electron microscopy (TEM). It is find that reducing of the lower critical solution temperature (LCST) of terpolymer microgels with the increasing amount of hydrophobic monomer NTBA in feed. It means increasing NTBA can effectively adjust of the LCST of terpolymer microgels. And we make a preliminary exploration on the drug loading and release.
  • Synthesis and Adsorption Properites of Pb2+ chromogenic imprinted adsorbent
    CHENG Wen-xia;LIU Cheng-lun;XIE Tai-ping
    . 2013, 44(04): 569-572.
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    A new type of Pb2+ chromogenic imprinted adsorbent was prepared by sol-gel approach with Pb2+ as the template and dithizone grafting onto the silica gel surface .The adsorbent was characterized by FT-IR and scanning electron microscopy. The adsorption property, chromogenic property and selective recognition ability of the adsorbent were studied by equilibrium-adsorption method. Results showed that the dithizone was coated on the silica gel through hydrogen bond. The chromogenic limit of the printed adsorbent was 10 μmol/L，the relative selectivity coefficient was 250 while Cd2+ existed; The extraction behavior of the Pb2+ was conformed by Langmuir’s equation and the enthalpy of adsorption was 66.054 KJ/mol. The adsorption capacity reached 97% in 5 min and it could be used for separation and determination of trace Pb2+ in the waste water.
  • A Novel filtration of cigarette smoke Prepared by Two Steps Grafting of AA and AMPS Monomer onto PP Matrix
    WANG Hai-tao;WE Jun-fu;WANG Ao;CHEN Yuan;ZHAO Yu;YANG Chuang
    . 2013, 44(04): 573-576.
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    In order to improve the poor adsorption for cigarette smoke and tar of polypropylene (PP) fiber, AA and AMPS were grafted onto PP fiber matrix by two steps plasma irradiation grafting for preparation a novel composite filtration of cigarette smoke PP-g-(AA+AMPS). The factors influenced the grafting degree were discussed, such as the irradiation time, concentration of monomer and the concentration of inhibitor. Attenuated total re?ection-Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM) were used to characterize the chemical and morphological changes of the original and grafted PP fiber matrix, the results indicated that AMPS was grafted onto the surface of PP fiber matrix. The results indicated that the filtration efficiency of PP fiber was improved significant after graft modification, the total particulate matter in mainstream cigarette smoke reduces 30.5%, and the concentration of tar and nicotine are decrease 43.2% and 31.7%, respectively.
  • Fabrication and Optimization of Integrated Magnetic Switch
    AI Ming-zhe;JIA Ya-ting;CHEN Zhong-zhi;XU Hui-zhong;PENG Bin
    . 2013, 44(04): 577-580.
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    In this paper, radio frequency and DC magnetron sputtering were used to prepare NiFe thin-film. The influence of the thickness of Ta buffer layer and the sputtering power of the NiFe thin-film were investigated. Results show that increase of the sputtering power can increase the MR of the NiFe film which is resulted from the enhanced (111) texture of the NiFe film. Lift-off procedures were used to fabricate the MR resistance bridge onto wafers. The chips show magnetic switch between at 5 and 10 Oe.
  • Preparation and electrical properties of insulating aluminum oxide thin films by sol-gel process
    SHAN Wei;YAO Man-wen;HU Bao-fu;YANG Peng-fei;YAO Xi
    . 2013, 44(04): 581-584.
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    Aluminum oxide thin films were prepared on various substrates by the sol-gel spin-coating process from a stable coating sol using 2-ethoxyethanol as solvent, aluminum isopropoxide as precursor and acetylacetone as chelating agent. The microstructure and the surface morphology of sol-gel films were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and metallurgical microscope. The results indicate that the thin films obtained are uniform, dense，crack-free and amorphous in structure. The J-E and J-t curves were measured to study the electrical properties of the films. When electric field strength is 0.5 MV/cm, the leakage current density is about 9.0×10-6A/cm2. The breakdown electric field Eb of the films is in the range of 2.0-3.0 MV/cm.
  • Preparation of single phase semiconducting Mg2Si film on Si substrate by low vacuum heat treatment
    XIAO Qing-quan;XIE Quan;SHEN Xiang-qian;ZHANG Jin-min;CHEN Qian
    . 2013, 44(04): 585-589.
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    Semiconducting Mg2Si films were prepared by magnetron sputtering, Mg film was deposited onto Si substrate and subsequent low vacuum heat treatment was carried out. X-ray diffraction, scanning electron microscopy and Raman spectra were performed to characterize and analyze the structure of films. Effects of heat treatment temperatures (350-550 ℃) and heat treatment time (3-7 h) on the formation of Mg2Si films were investigated under low vacuum (10-1-10-2 Pa). The results show that the optimal heat treatment conditions for preparing single phase Mg2Si film are 400-550 ℃ and 4-5 h in low vacuum. Two distinguished peaks at 256 cm-1 and 690 cm-1 are observed in Raman scattering spectra, which are characteristic peak position of Mg2Si.
  • Preparation and Properties of PVA-PAA-KOH Alkaline Polymer Electrolyte Membrane
    LU Xia;WU Ren-xiang;ZHU Yun-feng;LI Li-quan
    . 2013, 44(04): 590-594.
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    PAA was prepared by the situ polymerization of AA with various neutralization degrees in PVA solution under the action of initiator and crosslinker and PVA-PAA blended membrane was prepared by the solution casting method. PVA-PAA-KOH alkaline polymer electrolyte was activated by the alkaline solution. The morphology and structure of the polymer electrolyte were characterized by means of SEM, XRD and FTIR. The electrochemical properties were represented by the AC impedance and the cyclic voltammetry. The results indicated that a homogeneous PVA-PAA blended membrane was successfully obtained. The increased water content of the membrane and the decreased crystallinity of the PVA owed to the presence of PAA. The maximum ionic conductivity of the electrolyte reached to 3.55×10-2 S/cm. The alkaline polymer electrolyte with 7:3 mass ratio of PVA:AA could achieve a good synthetical property with electrochemical stability window more than 2V and could meet the demands of MH-Ni battery.
  • Application of diacetone acrylamide on air conditioning aluminum foil
    ZHANG Juan;SHEN Yi-ding;WANG Hai-hua;FEI Gui-qiang
    . 2013, 44(04): 595-598.
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    Abstract：Polyacrylate emulsion containing active Keto groups was prepared by using seed polymerization, in which diacetone acrylamide as function monomers. Then the coating used as air conditioning aluminum foil was obtained by blending polyacrylate emulsion and adipic dihydrazide. Solidified films of the polyacrylate were prepared by casting emulsions on Teflon surfaces. Crosslinking degree on the effect of film on the delimit resistance was diacussed. The surface roughness and surface morphology of the films ofwaterborne polyurethanes were observed by (SEM) and atomic force microscopy (AFM). The particle size and distribution of the resultant polymer emulsions was tested by the dynamic laser light scattering (DLLS). The results shows that, with the increase of the dosage of diacetone acrylamide，emulsion particle size increases first, then decreases, while emulsion viscosity decreases increased first,then decreases; delimit resistance increase. It was found that the tensile strength of films of polyacrylate increased while the elongation at break decreased with increasing dosage of diacetone acrylamide, and smoothness of films of polyacrylate increase.
  • Functionalization with self-assembled monolayers of 1-pyrenebutyric acid on glass wafer surfaces
    GAO Bo;YAN Hua;WANG Xue-mei
    . 2013, 44(04): 599-602.
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    A fluorescent film was fabricated by chemical immobilization of 1-pyrenebutyric acid on a glass wafer surface, the resulting layers were characterized by wettability studies and fluorescence measurements. The effect of temperature to the reaction between amidocyanogen and 1-pyrenebutyric acid on the wafer surface was shown by fluorescence spectra. Further experiments study the stability of the film. It is shown that immersing in solution at lower temperature producing significant improvements in the quality of the film. Finally，medium has significant effect on the stability of the film.
  • The Optimization of triple layer anti-refiection coatings and its application on solar cells
    GONG Chen;ZHANG Jing-quan;FENG Liang-huan;WU Li-li;LI Wei;LI Bing;ZENG Guang-gen;WANG Wen-wu
    . 2013, 44(04): 603-606.
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    The anti-reflection coatings with the structure of Al2O3/H4/MgF2 triple layer were prepared with electron beam evaporation technology on the glass substrate. The transmittance and surface morphology of the films were examined. The anti-reflection coating structure was optimized considering AM1.5 spectrum and the spectroscopy response band of CdS/CdTe thin film solar cells through TFCALC software simulation. Then the optimized anti-reflection coatings were prepared on the CdTe thin film solar cells. It was found that the quantum efficiency of solar cells with anti-reflection coatings increase by 7.3% than without, and the photoelectric conversion efficiency increased from 12.5% to 13.3%.
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