Hide/Show Apps

Bor nitrür nanotüp üretimi

Download
2010
Sezgi, Naime Aslı
Özmen, Didem
Balcı, Suna
The further developments in nanotechnology in last few years provide usage of nanoscale particles for many applications in various areas such as electronics, pharmaceutical, and biomedical due to their strengthened mechanical, thermal and electrical properties. Boron nitride nanotubes are a good example of nanoparticles. In this study, boron nitride nanotubes were successfully synthesized from the reaction of ammonia gas with mixture of boron and iron oxide. Physical and structural properties of the synthesized materials were determined by X-Ray Diffraction, Energy Dispersive X-Ray Spectroscopy, nitrogen sorption, X-Ray Photoelectron Spectroscopy, Fourier Transform Infrared Spectroscopy, and Scanning Electron Microscopy. Experiments were conducted in a tubular furnace at different temperatures, inlet gas compositions, and weight ratios of boron to iron oxide. Qualitative and quantitative chemical analyses of the reactor effluent stream were carried out using a mass spectrometer. The mass spectrometer analysis of the reactor effluent proved formation of nitrogen and hydrogen during the reaction of ammonia gas with the mixture of boron and iron oxide. Decomposition of ammonia gas was the only reaction taking place in the gas phase. Nitrogen formed from decomposition of the ammonia reacted with FeB formed from the reaction of boron and iron oxide to form boron nitride nanotubes. XRD results showed that hexagonal and rhombohedral boron nitrides and cubic iron were the solid phases formed in the product. FTIR and XPS results also indicated the presence of boron nitride and the atomic ratio of boron to nitrogen was compatible with the chemical stoichiometric relation between boron and nitrogen. It was observed that the crystanility of the product increased with an increase in temperature. The diameter of the produced nanotubes varied from 64 nm to 136 nm. The synthesized nanotubes exhibited Type II isotherms. The surface areas of the produced x boron nitride nanotubes decreased with a decrease in both temperature and the weight ratio of boron to iron oxide. The best temperature and weight ratio of boron to iron oxide to produce boron nitride nanotubes were found to be 1300°C and 20, respectively.