The Experts below are selected from a list of 40506 Experts worldwide ranked by ideXlab platform
Abbas Fahami - One of the best experts on this subject based on the ideXlab platform.
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influence of titania content on mechanosynthesis of chlorapatite titania composite Nanopowders
Ceramics International, 2014Co-Authors: Abbas Fahami, Bahman NasiritabriziAbstract:Abstract The effect of titania content on mechanochemical synthesis of chlorapatite–titania composite Nanopowders was studied for the first time. According to the obtained data, the phase compositions, structural features as well as morphological characteristics of the composites were influenced by the titania content. In the presence of 3–5 wt% titania, milling for 5 h resulted in the formation of chlorapatite–titania composite Nanopowders. The crystallite size of the samples was around 25±1 and 23±1 nm in the presence of 3 and 5 wt% titania, respectively. With increasing the titania content to 7 wt%, no chemical reaction happened during the milling. The composite Nanopowders showed high volume fraction of grain boundaries. Based on the FT-IR results, the products had high chemical purity which is very important in biomedical applications. The TEM images indicated that the composite nanopowder was composed of spheroidal particles with a mean size of around 35 nm. The proposed synthesis strategy provides a facile pathway to obtain novel chlorapatite-based composite Nanopowders with high purity and optimal properties.
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synthesis and characterization of chlorapatite zno composite Nanopowders
Ceramics International, 2014Co-Authors: Bahman Nasiritabrizi, Abbas FahamiAbstract:Abstract The influence of zinc oxide content on the formation of chlorapatite-based composite Nanopowders in the mechanically alloyed CaO–CaCl 2 –P 2 O 5 –ZnO system was studied. To mechanosynthesize composite Nanopowders, different amounts of hydrothermally synthesized zinc oxide nanoparticles (0–10 wt%) were mixed with ingredients and then were mechanically activated for 5 h. Results showed that in the absence of zinc oxide, high crystalline chlorapatite nanopowder was obtained after 5 h of milling. In the presence of 4 and 7 wt% zinc oxide, the main product of milling for 5 h was chlorapatite–zinc oxide composite nanopowder. On increasing the zinc oxide content to 10 wt%, composite nanopowder was not formed due to improper stoichiometric ratio of the reactants. The crystallite size, lattice strain, volume fraction of grain boundary, and crystallinity degree of the samples fluctuated significantly during the milling process. In the presence of 7 wt% zinc oxide, the crystallite size and crystallinity degree reached 51±2 nm and 79±2%, respectively. During annealing at 900 °C for 1 h, the crystallization of composite nanopowder occurred and as a result the crystallinity degree rose sharply to 96±3%. In addition, the crystallite size increased to 77±2 nm after annealing at 900 °C. According to SEM and TEM images, the composite nanopowder was composed of both ellipse-like and polygonal particles with a mean size of about 98 nm.
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Influence of titania content on mechanosynthesis of chlorapatite–titania composite Nanopowders
Ceramics International, 2014Co-Authors: Abbas Fahami, Bahman Nasiri-tabriziAbstract:Abstract The effect of titania content on mechanochemical synthesis of chlorapatite–titania composite Nanopowders was studied for the first time. According to the obtained data, the phase compositions, structural features as well as morphological characteristics of the composites were influenced by the titania content. In the presence of 3–5 wt% titania, milling for 5 h resulted in the formation of chlorapatite–titania composite Nanopowders. The crystallite size of the samples was around 25±1 and 23±1 nm in the presence of 3 and 5 wt% titania, respectively. With increasing the titania content to 7 wt%, no chemical reaction happened during the milling. The composite Nanopowders showed high volume fraction of grain boundaries. Based on the FT-IR results, the products had high chemical purity which is very important in biomedical applications. The TEM images indicated that the composite nanopowder was composed of spheroidal particles with a mean size of around 35 nm. The proposed synthesis strategy provides a facile pathway to obtain novel chlorapatite-based composite Nanopowders with high purity and optimal properties.
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Synthesis and characterization of chlorapatite–ZnO composite Nanopowders
Ceramics International, 2014Co-Authors: Bahman Nasiri-tabrizi, Abbas FahamiAbstract:Abstract The influence of zinc oxide content on the formation of chlorapatite-based composite Nanopowders in the mechanically alloyed CaO–CaCl 2 –P 2 O 5 –ZnO system was studied. To mechanosynthesize composite Nanopowders, different amounts of hydrothermally synthesized zinc oxide nanoparticles (0–10 wt%) were mixed with ingredients and then were mechanically activated for 5 h. Results showed that in the absence of zinc oxide, high crystalline chlorapatite nanopowder was obtained after 5 h of milling. In the presence of 4 and 7 wt% zinc oxide, the main product of milling for 5 h was chlorapatite–zinc oxide composite nanopowder. On increasing the zinc oxide content to 10 wt%, composite nanopowder was not formed due to improper stoichiometric ratio of the reactants. The crystallite size, lattice strain, volume fraction of grain boundary, and crystallinity degree of the samples fluctuated significantly during the milling process. In the presence of 7 wt% zinc oxide, the crystallite size and crystallinity degree reached 51±2 nm and 79±2%, respectively. During annealing at 900 °C for 1 h, the crystallization of composite nanopowder occurred and as a result the crystallinity degree rose sharply to 96±3%. In addition, the crystallite size increased to 77±2 nm after annealing at 900 °C. According to SEM and TEM images, the composite nanopowder was composed of both ellipse-like and polygonal particles with a mean size of about 98 nm.
Bahman Nasiri-tabrizi - One of the best experts on this subject based on the ideXlab platform.
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Influence of titania content on mechanosynthesis of chlorapatite–titania composite Nanopowders
Ceramics International, 2014Co-Authors: Abbas Fahami, Bahman Nasiri-tabriziAbstract:Abstract The effect of titania content on mechanochemical synthesis of chlorapatite–titania composite Nanopowders was studied for the first time. According to the obtained data, the phase compositions, structural features as well as morphological characteristics of the composites were influenced by the titania content. In the presence of 3–5 wt% titania, milling for 5 h resulted in the formation of chlorapatite–titania composite Nanopowders. The crystallite size of the samples was around 25±1 and 23±1 nm in the presence of 3 and 5 wt% titania, respectively. With increasing the titania content to 7 wt%, no chemical reaction happened during the milling. The composite Nanopowders showed high volume fraction of grain boundaries. Based on the FT-IR results, the products had high chemical purity which is very important in biomedical applications. The TEM images indicated that the composite nanopowder was composed of spheroidal particles with a mean size of around 35 nm. The proposed synthesis strategy provides a facile pathway to obtain novel chlorapatite-based composite Nanopowders with high purity and optimal properties.
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Synthesis and characterization of chlorapatite–ZnO composite Nanopowders
Ceramics International, 2014Co-Authors: Bahman Nasiri-tabrizi, Abbas FahamiAbstract:Abstract The influence of zinc oxide content on the formation of chlorapatite-based composite Nanopowders in the mechanically alloyed CaO–CaCl 2 –P 2 O 5 –ZnO system was studied. To mechanosynthesize composite Nanopowders, different amounts of hydrothermally synthesized zinc oxide nanoparticles (0–10 wt%) were mixed with ingredients and then were mechanically activated for 5 h. Results showed that in the absence of zinc oxide, high crystalline chlorapatite nanopowder was obtained after 5 h of milling. In the presence of 4 and 7 wt% zinc oxide, the main product of milling for 5 h was chlorapatite–zinc oxide composite nanopowder. On increasing the zinc oxide content to 10 wt%, composite nanopowder was not formed due to improper stoichiometric ratio of the reactants. The crystallite size, lattice strain, volume fraction of grain boundary, and crystallinity degree of the samples fluctuated significantly during the milling process. In the presence of 7 wt% zinc oxide, the crystallite size and crystallinity degree reached 51±2 nm and 79±2%, respectively. During annealing at 900 °C for 1 h, the crystallization of composite nanopowder occurred and as a result the crystallinity degree rose sharply to 96±3%. In addition, the crystallite size increased to 77±2 nm after annealing at 900 °C. According to SEM and TEM images, the composite nanopowder was composed of both ellipse-like and polygonal particles with a mean size of about 98 nm.
Bahman Nasiritabrizi - One of the best experts on this subject based on the ideXlab platform.
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influence of titania content on mechanosynthesis of chlorapatite titania composite Nanopowders
Ceramics International, 2014Co-Authors: Abbas Fahami, Bahman NasiritabriziAbstract:Abstract The effect of titania content on mechanochemical synthesis of chlorapatite–titania composite Nanopowders was studied for the first time. According to the obtained data, the phase compositions, structural features as well as morphological characteristics of the composites were influenced by the titania content. In the presence of 3–5 wt% titania, milling for 5 h resulted in the formation of chlorapatite–titania composite Nanopowders. The crystallite size of the samples was around 25±1 and 23±1 nm in the presence of 3 and 5 wt% titania, respectively. With increasing the titania content to 7 wt%, no chemical reaction happened during the milling. The composite Nanopowders showed high volume fraction of grain boundaries. Based on the FT-IR results, the products had high chemical purity which is very important in biomedical applications. The TEM images indicated that the composite nanopowder was composed of spheroidal particles with a mean size of around 35 nm. The proposed synthesis strategy provides a facile pathway to obtain novel chlorapatite-based composite Nanopowders with high purity and optimal properties.
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synthesis and characterization of chlorapatite zno composite Nanopowders
Ceramics International, 2014Co-Authors: Bahman Nasiritabrizi, Abbas FahamiAbstract:Abstract The influence of zinc oxide content on the formation of chlorapatite-based composite Nanopowders in the mechanically alloyed CaO–CaCl 2 –P 2 O 5 –ZnO system was studied. To mechanosynthesize composite Nanopowders, different amounts of hydrothermally synthesized zinc oxide nanoparticles (0–10 wt%) were mixed with ingredients and then were mechanically activated for 5 h. Results showed that in the absence of zinc oxide, high crystalline chlorapatite nanopowder was obtained after 5 h of milling. In the presence of 4 and 7 wt% zinc oxide, the main product of milling for 5 h was chlorapatite–zinc oxide composite nanopowder. On increasing the zinc oxide content to 10 wt%, composite nanopowder was not formed due to improper stoichiometric ratio of the reactants. The crystallite size, lattice strain, volume fraction of grain boundary, and crystallinity degree of the samples fluctuated significantly during the milling process. In the presence of 7 wt% zinc oxide, the crystallite size and crystallinity degree reached 51±2 nm and 79±2%, respectively. During annealing at 900 °C for 1 h, the crystallization of composite nanopowder occurred and as a result the crystallinity degree rose sharply to 96±3%. In addition, the crystallite size increased to 77±2 nm after annealing at 900 °C. According to SEM and TEM images, the composite nanopowder was composed of both ellipse-like and polygonal particles with a mean size of about 98 nm.
Jeong-hwan Song - One of the best experts on this subject based on the ideXlab platform.
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Facile glycothermal synthesis of ZnO nanopowder at low temperature
Ceramics International, 2016Co-Authors: Je-hyeok Ryu, Phimmavong Kongsy, Dae-young Lim, Seung-beom Cho, Jeong-hwan SongAbstract:Abstract ZnO nanopowder was synthesized using a relatively facile and convenient glycothermal process with various reaction temperatures and times. ZnO nanopowder was successfully synthesized at temperatures as low as 120 °C using zinc acetate as the Zn source and diethylene glycol as the solvent. No mineralizers or precipitation processes were used in the fabrication, which suggests that the spherical ZnO Nanopowders were directly prepared in the glycothermal process. The prepared ZnO Nanopowders were characterized using XRD, FE-SEM, TG-DTA, UV–vis, TEM, and PL measurements. The shape and dispersibility of the ZnO Nanopowders could be controlled by the glycothermal reaction conditions. The prepared hexagonal ZnO nanopowder exhibited a spherical shape with diameters of approximately 10–50 nm. When the reaction temperature was increased to above 200 °C, the shape of the ZnO powder changed from spherical to rod-like. The highest intensity of the UV emission peak centered at 383.5 nm was increased upon increasing the reaction temperature in the room temperature PL spectrum of the ZnO nanopowder synthesized using the glycothermal process, suggesting that the ZnO Nanopowders with the best crystallinity were obtained under these conditions.
Takayuki Watanabe - One of the best experts on this subject based on the ideXlab platform.
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growth model of binary alloy Nanopowders for thermal plasma synthesis
Journal of Applied Physics, 2010Co-Authors: Masaya Shigeta, Takayuki WatanabeAbstract:A new model is developed for numerical analysis of the entire growth process of binary alloy Nanopowders in thermal plasma synthesis. The model can express any nanopowder profile in the particle size-composition distribution (PSCD). Moreover, its numerical solution algorithm is arithmetic and straightforward so that the model is easy to use. By virtue of these features, the model effectively simulates the collective and simultaneous combined process of binary homogeneous nucleation, binary heterogeneous cocondensation, and coagulation among nanoparticles. The effect of the freezing point depression due to nanoscale particle diameters is also considered in the model. In this study, the metal–silicon systems are particularly chosen as representative binary systems involving cocondensation processes. In consequence, the numerical calculation with the present model reveals the growth mechanisms of the Mo–Si and Ti–Si Nanopowders by exhibiting their PSCD evolutions. The difference of the materials’ saturation pressures strongly affects the growth behaviors and mature states of the binary alloy nanopowder.
