15 July 2014, Volume 45 Issue 13

    

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研究 开发
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  Preparation and corrosion behavior of Ni-TiN coatings deposited by ultrasonic electrodeposition

  . 2014, 45(13): 1-0.

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  Ni-TiN coatings were successfully prepared by ultrasonic electrodeposition on the surface of mild steel. The coating microstructure, composition and corrosion behavior were investigated by atomic force microscopy, high-resolution transmission electron microscopy, X-ray diffraction, and scanning electron microscope. The results indicate that the grains of Ni-TiN coating are refined with the increase of ultrasonic power. TiN particles are uniformly distributed in Ni-TiN nanocoating, and matrix grain is refined. the average diameter of Ni grains and TiN particles are respectively 80 nm and 30 nm, respectively. In corrosion tests, the corrosion rate of Ni-TiN nanocoating is very small, and it is about 1.9×10-5 kg/(m2?h), and the surface is smoother, there are a few corrosion holes in the coating.
工艺 技术
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  Fabrication and properties of ultra-thin PVP gate dielectrics films by solvent-vapor-assisted process

  ;;;

  . 2014, 45(13): 2-0.

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  The ultra-thin PVP gate dielectrics films were fabricated by the solvent-vapor-assisted process. Based on this approach, the PVP films had low leakage current density（1.12×10-9A/cm2 at 1MV/cm；5.42×10-9A/cm2 at 2MV/cm）when their thickness were 10nm, and the capacitance per unit reached to 566nF/cm2. Furthermore，the surface roughness were decreased from 0.36nm to 0.21nm after the solvent vapor-assisted annealing，and the trap density in films were decreased by 26% analyzed by SCLC.
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  Analysis on microstructure and composition of SiC coated rigid carbon fibre felt prepared by silicon evaporation

  Bing WANG;;;;Jia-Yang Li

  . 2014, 45(13): 3-0.

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  SiC coated rigid carbon fibre felt was produced via the direct reaction between silicon vapor and carbon stemming from graphite coating carbon fiber and substrates by silicon evaporation. Successful silicon carbide layer calls for a graphite coating given on the substrate surface by means of a slurry coating technology. The microstructural characterisation including phase structure and components, surface and profile micrograph, microhardness of SiC coating were studied by XRD, SEM, EDS and microhardness tester. The influence of evaporation time and surface roughness of graphite coating on coating and forming course of SiC coating was investigated. The main results show that only β-SiC exists on coating surface evaporated after three hours and with the increase of evaporation time, density and continuity of coating increase and cracks and holes decrease. The grain size of silicon carbide becomes smaller with low surface roughness of graphite coating as reaction matrix. The microhardness of SiC coating evaporated on high surface roughness of graphite coating is larger.
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  Mechanism Investigation of Surface Alloying through Lost Foam Casting Technique

  CHEN Dong Feng ;CHEN dong feng

  . 2014, 45(13): 4-0.

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  Surface alloying forming mechanism was investigated under lost foam casting（LFC） technology through orthogonal experiment. Surface alloyed model was established and driving force was analyzed. Homogeneous alloyed layer has been formed on the Mg-alloy matrix on condition that the vacuum degree and metal grain size were different, pouring temperature was 780℃ respectively, scanning electron microscopy (SEM) was used to examined the change of surface layer microstructure, micro area composition analysis of new phase formed on the matrix and line scan composition characteristics on the surface were carried out. The results show that the surface layer consists of β- Mg17Al12 phase, micro-hardness value was enhanced greatly compared with the matrix. Analyzed the alloying mechanism and the important factors during the alloying process that influenced the formation of uniform alloyed layer, it has been found that alloying metal grain size and casting infiltration driving force are the key factors in the experiment, with the increase of grain size and vacuum degree, the surface alloying effect has become better.
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  Preparation and cutting performance of TiCN-based functionally gradient cermets

  siwen TANG

  . 2014, 45(13): 5-0.

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  TiCN-based functionally gradient cermets were prepared by controlling of the composition and atmosphere and by using TiCN-WC-Mo2C-TaC-Co-Ni as experimental materials. Material microstructure and phase composition were observed and analyzed by scanning electron microscopy with EDS and X-ray diffractometer, and the cutting performance was investigated by turning. The result shows that TiCN-based functionally gradient cermets with Ti-enriched surface layer, W-enriched middle layer and the bottom were obtained by the control of atmosphere when WC content was lower. Appropriate increasing of the sintering temperature was benefit to increase the thickness of gradient layers. WC was concentration at the surface when WC content was higher in raw composition sintering at nitrogen gas. The thickness of Ti and W enriched layer is about 15~20 microns when 15%WC-TiCN based ceramics sintered at 1460 ℃ in nitrogen atmosphere for 1 h. The (Ti,W,Mo) (C,N) diffraction peaks of the material surface shift to the right relative to the internal after nitriding sintering. In vacuum sintering, the element of Ti and W was distributed uniform in a vacuum sintering when WC content was low. With the increase of WC content, the layers with poor Ti and W-enriched in gradually were appeared on the surface; in the meantime, the thickness of W-enriched on surface layer was increased. When WC content is 24%, W enriched layer thickness is more than 25 microns. Cutting experiment shows that TiCN-based functionally gradient cermets with Ti-enriched surface layer is superior than that with W-enriched surface.
研究 开发
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  Structural Expressions and Retarding Mechanism of inorganic modified fire-retardant asphalt

  . 2014, 45(13): 6-0.

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  Considering the problem of heavy smoke, toxic, high cost of some flame retardants, two new inorganic flame retardants were developed, and the fire-retardant modified asphalts were prepared；In order to study the internal structure and the flame-retardant mechanism of our new developed flame-retardant asphalt, the combination between flame retardant particles and asphalt were analyzed by scanning electron microscopy (SEM) test and the effect of the flame retardants on the functional groups was studied by infrared spectroscopy (FTIR) test. The effect of inorganic fire-retardants on the nature of asphalt was analyzed by using TG experiment. The research results showed that the flame retardant effect of the modified asphalt is well; The inorganic fire-retardant modifiers can be evenly distributed in asphalt and there was no phenomenon of reunion. FTIR test shows that there is no covalent generating when the two flame retardants are added into the asphalt. The thermal weightlessness of inorganic modified fire-retardant asphalt is greater than that of base asphalt.
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  Prediction for corrosion resistance of pulse electrodeposite Ni-TiN Composite Coatings Using BP Artificial Neural Networks

  . 2014, 45(13): 7-0.

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  Synthesis and Characterization of PAMAM-COOH and Its Effect on Sanitary Properties of Microfiber Synthetic Leather

  Longfang Ren;Na Wang

  . 2014, 45(13): 8-0.

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  G0.5 PAMAM-COOH and G1 PAMAM-COOH were prepared by modifying G0.5 PAMAM and G1 PAMAM with hydrochloric acid and aldehyde acid respectively. The modifying conditions of G1 PAMAM with glyoxalic acid were optimized by single-factor experiment. The n(G1 PAMAM):n(aldehyde acid) was 1:12, the reaction temperature was 35℃ and the reaction time was 2h. The G0.5 PAMAM-COOH and G1 PAMAM-COOH were used to modify polyamide microfiber synthetic leather base. The results showed that the water vapor permeability of microfiber synthetic leather base increased by 26.97% and 34.59%. The SEM images of the modified base showed that the microfiber became loose and the pore became big. The water contact angle test revealed that the hydrophilic groups increased. Compared to unmodified base, the water penetration time of bases modified by G0.5 PAMAM-COOH and G1 PAMAM-COOH shortened by 71.74% and 78.26%. These showed that the sanitary properties of microfiber synthetic leather were greatly improved.
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  Sorption behavior of Rhodamine 6G onto sodium alginate graft poly (acrylic acid-co-2-acrylamido-2-methyl propane sulfonic acid )/ kaolin composite hydrogel

  ;;ma-tai DING;

  . 2014, 45(13): 9-0.

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  Research of alkaline treatment of bamboo fiber toughened cement

  . 2014, 45(13): 10-0.

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  Abstract: Cement is a kind of brittle material. It often occurrs brittle failure in the downhole which can cause the failure of well integrity and affect the exploitation .This paper is studied about the influence of the bamboo fiber on the mechanical properties of cement for toughening the cement. In the experiment, surface treatment of bamboo fiber used by sodium hydroxide solution; Investigated the influence of the modified bamboo fiber on the mechanical properties of cement; Analyzed the reasons why the hydrophilicity and the dispersity of bamboo fiber improved through IR , TG and SEM test; Compared the modified and unmodified bamboo fiber cement micro-morphology, and explored the toughening mechanism. The results showed that 1) the stickiness and dispersion improved , modified bamboo fiber surface glue was removed and polarity decreased through SEM after the fiber were soaked 24h in the 10% sodium hydroxide solution; 2) the cement included 5% bamboo fiber toughened obviously. Its ratio of bending-compressive strength increased 100% and the elasticity modulus decreased 31% than the blank sample; 3) bamboo fiber cement toughening mechanism is that the cohesiveness between the fiber and cement have improved. The fiber plays a role of "bridge" in cement crystals, and it closes bond between fiber and cement like "brace".
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  Preparation of Mn2O3 with Different Morphologies and Their Catalytic Performance for Chlorobenzene

  ;Quan-Rui quanrui YI;;

  . 2014, 45(13): 11-0.

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  The Mn2O3 catalysts with typical morphologies, such as core-shell spheres, hollow cubes and one-dimensional nanorods were synthesized by sacrificial template and hydrothermal methods, and their catalytic properties for oxidation of chlorobenzene (CB) were tested. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and so on. The XRD result indicated that all samples had the same crystal structure. The catalytic activity tests showed that the performance for CB oxidation depended on the morphology of Mn2O3, following in the order of hollow cubes > core-shell spheres > nanorods. The H2-TPR and N2 adsorption–desorption results demonstrated that the mobility of oxygen and specific surface area of the catalysts were considered as the dominant factors for low temperature catalytic destruction of CB.
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  Thermal stability study of the PVDF based porous composite separator for polymer lithium battery, Thermal stability study of the PVDF based porous composite separator for polymer lithium battery

  . 2014, 45(13): 12-0.

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  PVDF composite separator was prepared through solution blending method, using acetone as solvent, PVDF as film forming material and nano-silica as the filling. The study showed the separator reacted at 420℃ and decomposed completely at 500℃. The ARC curve illustrated the heat release rate of the separator reached threshold of 0.05K/min at 185℃. The SEM results showed the pore diameter was 2μm. The separator was beneficial to adsorb electrolyte because of many microporous. The resistance of the polymer lithium battery made by the separator was 0.85Ω?cm2. The surface temperature rising of the 40AH battery was 5.8℃, discharged at 3C rate at 55℃. The capacity of 14s-60AH batteries faded 16.2% after 500 cycles., PVDF composite separator was prepared through solution blending method, using acetone as solvent, PVDF as film forming material and nano-silica as the filling. The study showed the separator reacted at 420℃ and decomposed completely at 500℃. The ARC curve illustrated the heat release rate of the separator reached threshold of 0.05K/min at 185℃. The SEM results showed the pore diameter was 2μm. The separator was beneficial to adsorb electrolyte because of many microporous. The resistance of the polymer lithium battery made by the separator was 0.85Ω?cm2. The surface temperature rising of the 40AH battery was 5.8℃, discharged at 3C rate at 55℃. The capacity of 14s-60AH batteries faded 16.2% after 500 cycles.
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  Preparation and characterization of alumina fiber via solution blowing method

  ;; Yi-Xia ZHAO;

  . 2014, 45(13): 13-0.

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  Sol-gel and solution blowing techniques were incorporated to produce the as-spun alumina fiber followed by calcination. The resulting fibers were characterized using optical microscope, TGA and XRD. The results indicate that sol-gel solution viscosity plays the major role in as-spun fiber morphology and fiber diameter distribution. The as-spun fibers with a uniform diameter can be obtained when the solution viscosity is 3.10Pa.s,and the average diameter is 17.76μm. During the thermal treated process, the surfaces of the fibers are smooth with the low sintered temperature, whereas the temperature up to 900℃，the fibers become more fine and the surfaces is coarsen until 1100℃. It can be found that the organic ingredients pyrolysis completely at 600℃.Finally, the resulting fibers with γ phase are obtained after 1100℃ sintered treatment.
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  Study on effects of processing parameters on copper-coated tungsten powders prepared by electroless plating

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  . 2014, 45(13): 14-0.

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  The copper-coated tungsten powder was prepared by electroless plating method in this study. The effects of surface treatment, reducing agent, complexing agent, stabilizer, and pH value of the solution on copper coating were studied. Tungsten powder surface should be coarsened, sensitized and activated at first. By combination of two complexing agents of potassium sodium tartrate and EDTA-2Na, free copper particles are decreased, and solution stabilization and plating rate are increased. The maximum plating rate can be reached when the weight ratio of the two complexing agents. The stability of plating solution was also affected by reducing agent formaldehyde and solution pH value, and the optimum content of formaldehyde is 10-20ml/L and pH value is 12-13. The optimum temperature of plating solution is 45-55℃. The copper coating on tungsten particle is dense, uniform and complete.
综述 进展
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  Research Process of Solution processed Transparent oxide thin film transistor

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  . 2014, 45(13): 15-0.

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  Transparent oxide thin film transistor has attracted much attention due to advantages of a high field effect mobility, excellent uniformity, and the compatibility with flexible substrate compared to conventional amorphous and polycrystalline silicon thin film transistors, that can be widely used in active flat panel display areas, especially organic light emitting diode display driver back plane. Solution processed thin film transistor does not require high vacuum environment, low cost, simple process, easy to control compound ingredients, also can achieve uniform molecular level doped quantitative, meet the demand for new technology research and development. The research was concentrated in the film composition and process temperature on device performance. The all solution processed fabrication and low temperature preparation based on flexible substrate have also made good progress, which provide a reliable and low cost technology for the future flat display industry, However, it still has relative high fabrication temperature and poor stability. This paper summarizes the remarkable work、research direction and progress in the field.
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  Research progress on nano-carbon/dendrimers composites

  ; ;;;

  . 2014, 45(13): 16-0.

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  In recent years, nano-carbon/dendrimers composites have attracted intensive interests because of their unique structures and outstanding properties. In this paper, the research development and application prospects of nano-carbon/dendrimers composites materials prepared by dendrimers with fullerene,carbon nanotubes or graphene were reviewed.
工艺 技术
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  The Effects of Small Amounts of SiO2 on the Properties of Polyimide/Al2O3 Composite Films

  ; Ling Weng

  . 2014, 45(13): 17-0.

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  In this paper, the polyimide(PI)/Al2O3/SiO2 composite films with the same nano-alumina(Al2O3) content and the different nano-silica(SiO2) content were prepared. The morphology and molecular structure of the composite films were characterized by Scanning Electron Microscopy(SEM) and Fourier Transform Infrared Spectroscopy(FTIR) respectively. The SEM and FTIR results indicated that nanoparticles were homogeneously dispersed in the PI matrix, the addition of nanoparticles had no effect on the molecular structure of PI and the thermal imidization of polyamic acid. The mechanical properties, electric breakdown strength and Corona-resistant performance of the composite films were tested. Test results showed that the breakdown field strength and Corona resistant time of the composite film with 5wt‰ of nano-SiO2 content were 211.15kV/mm, 378min respectively and were superior to the composite films with 0wt‰, 1wt‰, 3wt‰, 7wt‰ of nano-SiO2 content, and its mechanical properties are more excellent.
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  Study on the Synthesis of Crosslinking Waterborne Polyurethane-Acrylic Composite Emulsion and the Film Properties

  . 2014, 45(13): 18-0.

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  A novel emulsion of crosslinked waterborne polyurethane-acrylic copolymers (PUA)was successfully synthesized by in-situ emulsion copolymerization method in this paper,using IPDI,PCDL-1000,BDO,DMPA,GMA as the main raw material.The effects of the content of crosslinking agent on the properties of composite emulsion and its films was studied systematically.FT-IR,TGA, XRD,SEM were employed to investigate the structures and properties of the composite latex and their polymers. The results showed that moderate crosslinking could contribute to improving the water resistance and mechanical properties of materials.When n(GMA)/n(DMPA)=0.1~0.2,the WPUA latex has a stable performance as well as an excellent thermal stability and water resistance of the polymer,the bibulous rate of the crosslinked films was low to 5.4%.The tensile strength of the crosslinked WPUA films achieved 28.9 MPa, increased by 173% of the uncrosslinked one.
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  Effect of Hydrophobic Alkyl Ester Side Chain on the Dispersion and Slump Retention Properties of Polycarboxylate Superplasticizer

  . 2014, 45(13): 19-0.

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  Abstract: In order to study how the hydrophobic side chain in polycarboxylate superplasticizer structure affect the slump loss of the fresh concrete, four polycarboxylate superplasticizer (PCA) with different hydrophobic side chain length were synthesized by free radical copolymerization of maleic anhydride (MAH), methallyl alcohol polyethylene oxide ether (TPEG) and acrylic alkyl ester using ammonium persulfate [(NH4)2SO4, APS] as initiator. The dispersing and flow retention performance of the four PCA was investigated respectively by testing the fluidity of cement paste. The adsorption mechanism of NPC was discussed by testing the adsorption amount and ζ-potential. The fluidities and flow loss of cement paste show that the dispersing performance of PCA gradually improves with the increase of the hydrophobic side chain length. The results of the ζ-potential and the continuous adsorption ability of PCA on the surface of cement particles gradually increase with increasing the length of the hydrophobic side chain.
研究 开发
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  Preparation and Performance of Ethylene-Vinyl Alcohol Copolymer Coatings on 316L Stainless Steel Stent

  ;xia fa feng

  . 2014, 45(13): 20-0.

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  EVAL coatings were prepared on the surface of 316L stainless steel by ultrasonic-sprayed deposition method. The surface morphology and performance of coatings were investigated using AFM, contact angle meter and SEM. The results show that the surface roughness of 316L steel, S-EVAL and US-EVAL coatings is Ra=123.677 nm, Ra=14.994 nm, and Ra=2.830 nm, respectively. Surface contact angle of S-EVAL and US-EVAL coatings is 75.6°and 74.3°, which is less than that of 316L stainless steel. And the adhered and clustered platelet number of US-EVAL coating is the least.
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  Effects of pH on the properties of MAA/MMA copolymer emulsion

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  . 2014, 45(13): 21-0.

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  Preparation and properties of pH-sensitive SA/GO composite hydrogel beads

  . 2014, 45(13): 22-0.

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  Graphene oxide was individually dispersed in SA aqueous solution through physical blending , and then the SA and SA/GO hydrogel beads were prepared by Ca2+ crosslinking successfully. The chemical structure and properties were characterized by FTIR, XRD, TGA. The swelling and adsorption properties of hydrogel beads were studied .The effect factors including contact time, dosage and MB initial concentration on the adsorption properties of methylene blue onto calcium alginate immobilized grapheme oxide composites hydrogel beads were investigated. The results indicate that SA/GO beads exhibit higher swelling ratio in pH=7.4 buffer solution than in pH=1.2 solution and show pH sensitivity. With increasing the amount of GO, the adsorption capacities increase, while the swelling ratios decrease gradually. The maximal removal percentage and adsorption capacity of MB on the beads are up to 96.78% and 153.8mg/g with 5 wt% GO incorporated respectively, and the adsorption of MB is in accordance with Langmuir model.
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  Antioxidant Activity of Hydrogen-Reduced Alkali Lignin Prepared Using SO42-/ZrO2 as Catalyst

  Sheng-Ming ZHANG;;MA YANLI;

  . 2014, 45(13): 23-0.

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  In this study, laboratory-prepared SO42-/ZrO2 catalysts were used for the reduction of alkali lignin by hydrogen in order to increase alkali lignin activity，and the active functional groups of alkali lignin were analyzed by chemical method，the antioxidation abilities of alkali lignin was evaluated on DPPH radicals scavenging, superoxide anion radicals scavenging and reducing power. Results showed that the contents of total hydroxyl and phenolic hydroxyl of alkali lignin after reaction were 9.39% and 3.32%，with an increase of 55.98% and 15.28% respectively compared with the original alkali lignin，both alkali lignin and its reduced products had strong radical scavenging activity against DPPH at a concentration ranging from 0.005 to 0.160mg/ml in reaction system, the maximum DPPH free radical scavenging rates of activated alkali lignin were 80.91%, with an increase of 4.61% compared with the original alkali lignin, alkali lignin had low radical scavenging activity against superoxide anion at a concentration ranging from 0.0025 to 0.080mg/ml in reaction system, the reducing power of alkali lignin after reaction was enhanced at a concentration ranging from 0.002 to 0.060mg/ml in reaction system. Alkali lignin could be used as natural antioxidant.