Electrical conductivity and seebeck coefficient at different temperatures,and thermal conductivity at room temperature for various doped polyaniline (PAn) samples were measured,and the thermoelectric figure of merit Z...
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Electrical conductivity and seebeck coefficient at different temperatures,and thermal conductivity at room temperature for various doped polyaniline (PAn) samples were measured,and the thermoelectric figure of merit ZT was *** effects of preparation methods and temperature on thermoelectric properties were *** results show that the electrical conductivity and the seebeck coefficient of PAn are strongly dependent on the preparation conditions and *** electrical conductivity becomes larger and the seebeck coefficient becomes smaller as PAn molecular weight *** by organic acid and HCl results in an increase in both electrical conductivity and Seebeck coefficient of PAn,and therefore ZT *** electrical conductivity increases and the seebeck coefficient decreases as the temperature increases when TT *** thermal conductivity is lower,and insensitive to the sample preparation conditions.
The objective of this paper is to understand the flow mechanism through visualization experiments and discuss theinfluence of process parameters on mold filling process. A 2D leakage flow model is developed to simulat...
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The objective of this paper is to understand the flow mechanism through visualization experiments and discuss theinfluence of process parameters on mold filling process. A 2D leakage flow model is developed to simulate the moldingprocess, and the simulation results show good agreement with experiments.
The homogeneous glass samples of the (1-x)As 2S 3 xCdCl 2 where x=0 and 0.05 were prepared by the conventional melt quenched *** addition of 5mol% CdCl 2 enhanced the glass transition temperature of pure As 2S ...
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The homogeneous glass samples of the (1-x)As 2S 3 xCdCl 2 where x=0 and 0.05 were prepared by the conventional melt quenched *** addition of 5mol% CdCl 2 enhanced the glass transition temperature of pure As 2S 3 glass sample by about 30℃.Based on the experimental data,the microstructure is considered to be that the discrete molecule species of AsCl 3 and nanocrystal CdS is homogeneously dispersed in the disordered polymer network formed by AsS 3 pyramids interconnected by sulfur bridges.
Highly photoactive bi-phase nanocrystalline TiO2 photocatalyst was prepared by a solvent evaporation-induced crystallization (SEIC) method, and calcined at different temperatures. The obtained TiO2 photocatalyst was c...
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Highly photoactive bi-phase nanocrystalline TiO2 photocatalyst was prepared by a solvent evaporation-induced crystallization (SEIC) method, and calcined at different temperatures. The obtained TiO2 photocatalyst was characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM) and BET surface areas. The photocatalytic activity was evaluated by the photocatalytic oxidation of acetone in air. The results show that solvent evaporation can promote the crystallization and phase transformation of TiO2 at 100°C. When calcination temperatures are below 600°C, the prepared TiO2 powders show bimodal pore size distributions in the mesoporous region. At 700°C, the pore size distributions exhibit monomodal distribution of the inter-aggregated pores due to the collapse of the intra-aggregated pores. At 100°C, the obtained TiO2 photocatalyst by this method shows good photocatalytic activity, and at 400°C, its photocatalytic activity exceeds that of Degussa P25. This may be attributed to the fact that the prepared TiO2 photocatalyst has higher specific surface areas, smaller crystallite size and bimodal pore size distribution.
A novel and efficient methodology for obtaining highly active photocatalyst of bi phase TiO 2 with small particle size and high specific surface area was developed by solvent evaporation induced crystallization (SE...
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A novel and efficient methodology for obtaining highly active photocatalyst of bi phase TiO 2 with small particle size and high specific surface area was developed by solvent evaporation induced crystallization (SEIC) method at low temperature. The prepared TiO 2 powder was characterized with X ray diffraction (XRD), transmission electron microscopy (TEM) and BET surface areas. The photocatalytic activity was evaluated by the photocatalytic oxidation of acetone in air. The results showed that the photocatalytic activity of the TiO 2 powder prepared by this method approached that of Degussa P25. This may be attributed to the fact that the prepared TiO 2 powder had larger specific surface areas (265 m 2·g -1 ) and smaller crystallite size (about 5 nm), but relatively low crystallinity, as compared with Degussa P25.
Ti 3SiC 2 materials have been fabricated by spark plasma sintering of the elemental powders with the addition of Al. At the heating rate of 80 ℃/min and under the pressure of 30 MPa, the ideal synthesis temperature o...
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Ti 3SiC 2 materials have been fabricated by spark plasma sintering of the elemental powders with the addition of Al. At the heating rate of 80 ℃/min and under the pressure of 30 MPa, the ideal synthesis temperature of Ti 3SiC 2 is in the range of 1 1501 250 ℃. The addition of Al is in favor of the formation of Ti 3SiC 2. The synthesized compound has the molecular of Ti 3Si 0.8Al 0.2C 2 and lattice parameters of a=0.306 9 nm, c=1.767 0 nm. Its grain is plane-shape with a size of about 50 μm in the elongated dimension. The prepared material has Vickers hardness of 3.55.5 GPa(at 1 N and 15 s) and is as readily machinable as graphite’s.
CoSb/sub 3/ micrometer powder was synthesized by solid-state reaction using high purity powder of Co, Sb as the starting materials. CoSb/sub 3/ nano-powder and block material with nanostructure were prepared by high-e...
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CoSb/sub 3/ micrometer powder was synthesized by solid-state reaction using high purity powder of Co, Sb as the starting materials. CoSb/sub 3/ nano-powder and block material with nanostructure were prepared by high-energy ball-milling and by Spark Plasma Sintering (SPS), respectively. The influence of mass ratio of big balls and small balls, milling speed and time on particles size of CoSb/sub 3/ powder, and sintering temperature and time on grains size of CoSb/sub 3/ were investigated. The influence of nanostructure on thermal transport properties of CoSb/sub 3/ was also studied.
Since some transition metal diborides have the same crystal structure with TiB 2, which can react with TiB 2 to form solid solution by adequate technique. With ZrB 2 used as additive, the TiB 2-ZrB 2 solid solution wa...
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Since some transition metal diborides have the same crystal structure with TiB 2, which can react with TiB 2 to form solid solution by adequate technique. With ZrB 2 used as additive, the TiB 2-ZrB 2 solid solution was prepared by hot pressing. The effects of additive content on mechanical properties of composite were investigated. The microstructure analyzing were employed by EPMA, SEM and TEM. It is shown that TiB 2 can partly form solid solution with ZrB 2 and redound to gain uniform grains, which results in the increase of mechanical properties.
Composite particles consisting of polyaniline( PAn) core and barium tilanate ( BaTiO3) Layer shell were synthesized. The PAn-BaTiO3 composites particles were characterized with TEM and XRD. The dielectric behavior of ...
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Composite particles consisting of polyaniline( PAn) core and barium tilanate ( BaTiO3) Layer shell were synthesized. The PAn-BaTiO3 composites particles were characterized with TEM and XRD. The dielectric behavior of particles was tested and the electrorhcologicak(ER) behavior of the suspensions of PAn/ BaTiO3 panicles in chlorinated paraffin oil with a 20vol % was investigated under DC electric field. The results show that the ER effect of composite particle is far stronger than that of pure polyaniline and barium titanate which mere synthesized by the stone method. pH and thickness of BuTiO3 have an important. influence on the ER effects.
The influence of pretreatment of fibre on interfacial and mechanical properties of glass fibre/ polypropylene composites was investigated. Firstly, the glass fibres were coated with the blends of m-IPP (maleic anhydri...
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The influence of pretreatment of fibre on interfacial and mechanical properties of glass fibre/ polypropylene composites was investigated. Firstly, the glass fibres were coated with the blends of m-IPP (maleic anhydride grafting isotatic polypropylene ) and m-APP ( maleic anhydride grafting amorphous polypropylene) in different, ratios. Secondly, the interfaced reaction of the coated composites was analysed by FTIR, which shows that the interfacial chemical reaction between m-IPP/m-APP in the fibre coating and the fibre surface- bound coupling agent is in existence. Thirdly, the microstructure of the coated composites wax studied by SEM. The results indicate that the coating treatment is effective on improving interfacial adhesion of the, fibre-matrix and the right amount of m-APP added to the coal impels the plastic deformation surrounding the point of cracks , which makes cracks turn to region and prevents from further interface debonding. Lastly, the mechanical properties were evaluated by measurement, of the flexural strength and impact strength of the composites. It was found that, the flexural strength and impact strength of the composites with coating fibre are higher than those of uncoating fibre composite. The results of these investigations draw the conclusion that the pretreatment of fibre with m-IPP/m-APP blends can form an optimize interlayer between the fibre and the PP matrix, which improves both the strength and lough-ness of the composites.
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