scholarly journals Synthesis of Boron Nitride Nanotubes by Self-Propagation High-Temperature Synthesis and Annealing Method

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Jilin Wang ◽  
Yunle Gu ◽  
Laiping Zhang ◽  
Guowei Zhao ◽  
Zhanhui Zhang
Keyword(s):  
High Temperature ◽  
Boron Nitride ◽  
Average Diameter ◽  
Boron Nitride Nanotubes ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Effects Of Temperature ◽  
Temperature Time ◽  
Annealing Method ◽  
Bn Nanotubes

High-quality boron nitride nanotubes were synthesized by annealing porous precursor in flowing NH3gas at 1150°C. The porous precursor B18Ca2(MgO)9was produced by self-propagation high-temperature synthesis (SHS) method using Mg, B2O3, and CaB6as the starting materials, which played an important role in synthesis of BN nanotubes in large quantities. Samples were characterized by SEM, TEM, EDX, HRTEM, X-ray powder diffraction (XRD), Raman, and Fourier transform infrared (FTIR) spectroscopy. The as-synthesized BN nanotubes have an average diameter of about 150 nm with a wall/diameter ratio of 2/3. Mean length of the BN nanotubes was more than 10 μm. The effects of temperature, time, and the possible mechanism of the growth of the BN nanotubes were also discussed.

Selective Synthesis of Boron Nitride Nanotubes

2011 ◽  
Vol 694 ◽  
pp. 408-412
Author(s):  
Lai Ping Zhang ◽  
Ji Lin Wang ◽  
Guo Wei Zhao ◽  
Zhan Hui Zhang ◽  
Fang Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Boron Nitride ◽  
Boron Nitride Nanotubes ◽  
Selective Synthesis ◽  
Controllable Synthesis ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Transmission Electron ◽  
Bn Nanotubes ◽  
Shs Method

Four types of boron nitride (BN) nanotubes are selectively synthesized by annealing porous precursor in flowing NH3 and NH3/H2 atmosphere at temperature ranging from 1000 to 1200°C in a vertical furnace. The as-synthesized BN nanotubes, including cylinder, wave, bamboo and bubble-chain, are characterized by scanning and transmission electron microscopy. Selectivity of BN nanotubes is estimated as approximately 80 to 95%. The porous precursor B31Fe17(MgO)27 prepared by self-propagation high-temperature synthesis (SHS) method plays a key role in controllable synthesis of the as-grown BN nanotubes. The chemical reaction and annealing mechanism are also discussed.

High-Yield Synthesis of Bamboo-Like BN Nanotubes Using Self-Propagation High Temperature Synthesized Porous Precursor

2011 ◽  
Vol 694 ◽  
pp. 59-63
Author(s):  
Lai Ping Zhang ◽  
Ji Lin Wang ◽  
Yun Le Gu ◽  
Guo Wei Zhao ◽  
Qiong Li Qian ◽  
...  
Keyword(s):  
High Temperature ◽  
Boron Nitride ◽  
Synthesis Method ◽  
Chemical Vapor ◽  
Boron Nitride Nanotubes ◽  
High Yield ◽  
Synthesis Process ◽  
Chemical Vapor Deposition Method ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

High-yield and high-purity bamboo-like boron nitride nanotubes were synthesized via an effective chemical vapor deposition method by annealing porous precursor under ammonia atmosphere at 1150 °C. The porous precursor, prepared by self-propagation high temperature synthesis method, was the key to bulk synthesis process. The as-synthesized boron nitride nanotubes were characterized by SEM, TEM, HRTEM, XRD, Raman and FTIR spectroscopy. These nanotubes had a bamboo-like structure with uniform diameters about 90 nm and length of more than 10 μm. The associated growth model is proposed in this paper.

Preparation of Submicron Metastable Spherical β-Bi2O3 Particles by Self-Propagating High-Temperature Synthesis Method

2019 ◽  
Vol 19 (11) ◽  
pp. 7436-7441
Author(s):  
Chu Zhang ◽  
Qi-Yu Wang ◽  
Ming-De Li ◽  
Guo-Dong Zhang
Keyword(s):  
High Temperature ◽  
High Efficiency ◽  
Synthesis Method ◽  
Reaction System ◽  
Average Diameter ◽  
Spherical Particles ◽  
Molar Ratio ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
One Step

Sub-micrometer particles of β-Bi2O3 were successfully synthesized via a one-step self-propagating high-temperature synthesis (SHS) method for the first time. The experiments were carried out in the air at room temperature. The products were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). In this study, three experiments were designed to optimize the heat source, Bi source and additive for the reaction system. Results showed that the system composed of Al, Bi2O3 and Al2O3 powders could synthesize monodisperse high-purity β-Bi2O3 spherical particles with the average diameter of 369 nm and the as-prepared products kept stable after being exposed in air for one month. Then, the influences of the ratio of the three components on system were investigated. Interestingly, it was found that a slight adjustment on the ratio of Al:Bi2O3:Al2O3 had significant effects on the reactions happening in a system. Specifically, when the amount of Al2O3 exceeds the molar ratio of 2:1:1 (Al:Bi2O3:Al2O3), it is difficult to ignite the reaction system; when the amount is less than 2:1:0.5, the reaction system becomes too violent to obtain pure products. However, there are no obvious differences on the morphology and structure of final products with the two ratios because of few changes in adiabatic temperature. Preparation of β-Bi2O3 by SHS technique enjoying many advantages, such as high efficiency, inexpensive experimental equipment and simple processes, would has a promising prospect for industrial application.

Obtaining the Nanostructured Nitride Composition TiN-BN Powder by the Self-Propagating High-Temperature Synthesis from the Azide KBF4-NaN3-Na2TiF6 and "NH4BF4-NaN3-Na2TiF6 Systems

2014 ◽  
Vol 698 ◽  
pp. 507-512
Author(s):  
Irina Kerson ◽  
Ljudmila Shiganova
Keyword(s):  
High Temperature ◽  
Boron Nitride ◽  
Sodium Azide ◽  
Composite Powder ◽  
The Self ◽  
Nanosized Powder ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Halide System ◽  
One Step

This paper presents the results of a study on the preparation of nanostructured nitride composition TiN-BN in the boron halide - sodium azide - titanium halide system by the azide SHS technology. SHS-Az technology makes it possible to produce powders having the desired properties, only in one step, without blending separately prepared powders of titanium nitride and boron nitride, and to obtain the final product in the form of micro-and nanosized powder nitride compositions TiN-BN by using complex halides of titanium and boron. Thus, the composite powder TiN and BN obtained from the KBF4-NaN3-Na2TiF6» and «NH4BF4-NaN3-Na2TiF6 systems can be classified as a nanostructured powder (nanopowder).

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