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摘要: The zinc (Zn) substituted hydroxyapatite were synthesized using a chemical precipitation method. The chemical precursors were prepared from di-ammonium hydrogen orthophosphate, calcium oxide (CaO) derived from chicken eggshell and zinc nitrate (Zn(NO3)2). The Zn(NO3)2 contents in the prepared samples were varied from 1 to 25 %wt of CaO. The Zn substituted hydroxyapatite were heated at the various temperatures from 200 to 1300 °C in the furnace with an incremental temperature of 100 °C. The crystal structure, function group and morphology of sample were analyzed by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM), respectively. The results show that the hydroxyapatite doped Zn was a hydroxyapatite phase as well as pure hydroxyapatite. The crystalline size of sample decreased with increasing the Zn content. And, the crystallinity of hydroxyapatite phase was increased following by increasing heat treatment temperature. However, the amount of Zn has the effect on phase transformation of hydroxyapatite phase after heat treatment. Zn concentration accelerates hydroxyapatite transforms to β-tricalcium phosphate phase.
摘要: At present the applications of the conductive polymer are monitor, batteries and the sensors but there have been limitations due to the manufacturing costs, material inconsistencies, toxicity, poor solubility in solvents, and inability to directly melt process. Regarding these problems, in this research to studies the condition to enhance the conductive polymer were conducted via the carbon dioxide plasma technique coated on ITO-PET. The plasma power is 50, 75, 100, 125 and 150 watts in the vacuum conditions for periods 10, 20 and 30 mins respectively. The electrical properties were measured via the 4 point probe. The contact angle for analyzing the hydrophobic was analyzed. The result demonstrated that the power of the plasma and the time has influence on the conductive polymer. With the time for doping at 20 mins the current increased compare to the control item. However, with the time doping at 10 and 30 mins the current decreased. The maximum current at 10 mins doping is 22 mA at the 7 volts in the conduction of 75 watts plasma power. The contact angle of the ITO-PET polymer decrease from 110 degree to 44-95 degree. Henceforth when using the carbon dioxide plasma the phenomenal of hydrophilic increases.
摘要: The thermal decomposition was used to prepare BaTiO3 powders. Using BaCO3 and TiO2 powders as precursors and heat treatment in the temperature range of 600-1000 °C for 6 hr. The final product (BaTiO3) proceeds through a trace amount of Ba2TiO4. The phase transformation was investigated by X-ray diffraction (XRD) as a function of sintering temperature. The results show that the microstructures of BaTiO3 were developed during sintering at different temperature. In additional, the particle growth of BaCO3 and TiO2 are the major factors to affect of the particle growth mechanism.
摘要: The granular structure of ceramic material influences the electrical properties. Ceramics of YMNO (Y2NiMnO6) doped with Nd were produced by compression and sintering. Grain size was determined from SEM image analysis. Generally, As the Nd dopant concentration was increased, the grain size increased with sintering time. However, at the highest dopant levels of 30% and 20% Nd, a large range in grain size was observed with regions of defective growth. In contrast, a more uniform grain growth was seen for the 10% Nd doped ceramic at all sintering times.
摘要: Bismuth borophosphate glasses containing different doping cerium oxide have been synthesized at 1200 °C by melt-quenching technique. The doping concentration of the Ce3+ was varied from 0.05 mol% to 2.0 mol%. The glass samples were characterized through optical absorption and luminescence spectral measurements. UV-visible and near infrared absorption spectra of glass samples were not observed nevertheless the absorption edge was shift to the longer wavelength. The photoluminescence and radioluminescence spectra show emission bands around 367 nm under 317 nm excitation wavelength. Also, the highest emission intensity was found at 0.5 mol% CeF3 dopant for both of photoluminescence and radioluminescence.
摘要: In this work, the optical and luminescence properties of Dy2O3 doped barium phosphate glass with different alkaline earth oxides (MgO, CaO and SrO) have been investigated. The glass samples were prepared by the melt-quenching technique at the melting temperature of 1200 °C. The absorption spectra of glasses were recorded in the ultraviolet, visible and near infrared (UV-Vis-NIR) region. The absorption bands centered at 385, 424, 452, 472, 754, 803, 901, 1093, 1273 and 1683 nm, respectively have been observed. The emission spectra of glass samples centered at 482, 574, 662 and 751 nm, respectively have been observed with 350 nm excitation wavelength. The result of radioluminescence spectra were slightly different with photoluminescence spectra. The coordinate of emitting color (x, y) for 350 excitation wavelength is 0.3781 and 0.4252, respectively which is located in white light region of CIE diagram.
摘要: The combination of elastic natural rubber (NR) and conductive graphene were assessed for such improved electromechanical properties that are promising material in an actuator applications. For this work, dielectric elastomer composite films were prepared with varied graphene contents. These films were fabricated by solution casting method. The morphology along with electrical and mechanical properties, and specifically the electrostrictive coefficient, were studied. The electrostrictive behavior was determined from electric field induced strain, observed with a photonic displacement apparatus in the film thickness direction. It is shown that the electrostrictive coefficient for the NR/Graphene composite has already raised over 3.7 times compared to the neat natural rubber by the reason of an interfacial polarization. The surface between NR matrix and graphene filler generates the larger permittivity. Meanwhile, the Young's modulus was quite invariant. Consequently, the enlarging of the electrostrictive coefficient under low electric field of the NR/Graphene composites is representing a potentially good actuation response base on the electrostriction phenomena.
摘要: The combination of carbon materials and polymer has been well studied according to their compatable mixture in polymer with promising properties. Due to their excellent electrical and thermal properties for some types of carbons such as carbon nanotubes and graphite, they have been selected as component for nanocomposites. Here, capability of multi-walled carbon nanotubes (MWNTs) and graphite for nanocomposites were demonstrated. Nanotubes were functionalized by chemical process, and added into polyvinyl chloride (PVA) matrix. They were then used as main filler to modify thermal and electrical conductivities. Conductivities of different composite mixtures were finally investigated. With the use of low total amount of carbon materials, it was found that although there is no significant change in electrical and thermal conductivities, the highest conductivities could be obtained from MWNT to graphite ratio of 1:1 in PVA matrix, while the G-band mode does not give a rise to electron transfer.
摘要: Determining the structure of ceramic materials is essential in order to fully characterize the electrical properties and improve existing materials. YMNO ceramics (Y2NiMnO6) prepared by compression and sintering were doped with TiO2 and analyzed using XRD and SEM. The calcined sample prior to sintering contained phases of the YMNO double perovskite and TiO2. Following sintering at 1400°C, the perovskite structure was replaced by Y2Ti2O7 fcc structure, and the grain size was found to increase with sintering time up to 18 hours. This sets a limit to the amount of TiO2 which can be used to successfully dope the YMNO ceramic.