PTFE dispersion composites filled with nanometer ZnO were successfully prepared by controlling stirring speed and using ultrasonic mixture with no damage to PTFE dispersion. Properties of PTFE composites, such as wear...PTFE dispersion composites filled with nanometer ZnO were successfully prepared by controlling stirring speed and using ultrasonic mixture with no damage to PTFE dispersion. Properties of PTFE composites, such as wear rate, friction coefficient and thermal conductivity coefficient were tested respectively. Also, the grain size of nanometer filler in composites were observed by different methods, such as small angle X-ray scattering (SAXS), transmission electron microscopy (TEM) and dynamic light scattering particle size distribution analyzer (DLSPSDA). Results show that nanometer ZnO fillers can further improve properties of PTFE-based composite, and its properties varies with the content of the fillers.展开更多
Nanometer ZnO particles were synthesized by evaporating of zinc powders of averageparticle size of 370μm studied by XRD, TEM and electron diffraction. The particleswere formed by the oxidation of evaporated zinc vapo...Nanometer ZnO particles were synthesized by evaporating of zinc powders of averageparticle size of 370μm studied by XRD, TEM and electron diffraction. The particleswere formed by the oxidation of evaporated zinc vapor in the air. It was found that the particles range from 70 to 100nm in average particle size. The effect of experimental parameters was investigated, the increase of the air flow-rates reduced the average particle size, while increasing the evaporation temperature and the amount of metal charged increased the average particle size. TEM of the particles collected showed that the crystal habits of particles have a tetrapod-like of wurtzite structure consists of four needle crystals. It was found by electron diffraction that all particles were single crystal.展开更多
ZnO nanocrystals were prepared by a direct current electrochemical deposition process under 3.0V working voltage and 30A/m^2 current density using zinc sulfate as raw materials.The nanocrystals were characterized by X...ZnO nanocrystals were prepared by a direct current electrochemical deposition process under 3.0V working voltage and 30A/m^2 current density using zinc sulfate as raw materials.The nanocrystals were characterized by X-ray diffraction (XRD)and transmission electron microscopy(TEM).The results indicated that the nanocrystals are hexagonal wurtzite ZnO with particle size range of 25nm～40nm without any treating.Gas sensing properties of the sensors were tested by mixing a gas in air at static state;the tested results showed that the sensors based on nanocrystalline ZnO had satisfied gas sensing properties to H_2S gas at rather low temperature.展开更多
文摘PTFE dispersion composites filled with nanometer ZnO were successfully prepared by controlling stirring speed and using ultrasonic mixture with no damage to PTFE dispersion. Properties of PTFE composites, such as wear rate, friction coefficient and thermal conductivity coefficient were tested respectively. Also, the grain size of nanometer filler in composites were observed by different methods, such as small angle X-ray scattering (SAXS), transmission electron microscopy (TEM) and dynamic light scattering particle size distribution analyzer (DLSPSDA). Results show that nanometer ZnO fillers can further improve properties of PTFE-based composite, and its properties varies with the content of the fillers.
文摘Nanometer ZnO particles were synthesized by evaporating of zinc powders of averageparticle size of 370μm studied by XRD, TEM and electron diffraction. The particleswere formed by the oxidation of evaporated zinc vapor in the air. It was found that the particles range from 70 to 100nm in average particle size. The effect of experimental parameters was investigated, the increase of the air flow-rates reduced the average particle size, while increasing the evaporation temperature and the amount of metal charged increased the average particle size. TEM of the particles collected showed that the crystal habits of particles have a tetrapod-like of wurtzite structure consists of four needle crystals. It was found by electron diffraction that all particles were single crystal.
文摘ZnO nanocrystals were prepared by a direct current electrochemical deposition process under 3.0V working voltage and 30A/m^2 current density using zinc sulfate as raw materials.The nanocrystals were characterized by X-ray diffraction (XRD)and transmission electron microscopy(TEM).The results indicated that the nanocrystals are hexagonal wurtzite ZnO with particle size range of 25nm～40nm without any treating.Gas sensing properties of the sensors were tested by mixing a gas in air at static state;the tested results showed that the sensors based on nanocrystalline ZnO had satisfied gas sensing properties to H_2S gas at rather low temperature.
