The Synthesis Of Processing Parameters And Nitrogen Beam Bombardment Modification On Carbon Nanotubes By CVD Method

Since carbon nanotubes were found, it caused widespread concern. After nearly two decades of research, people had the more profound understanding of the carbon nanotubes’ mechanical properties and microstructures, which had made important progress in basic research and application areas. At present a bottleneck in the field of carbon nanotube is whether can we make controllably carbon nanotubes under the requirements of people.This topic was based on the basic conditions of our laboratory, and the influencing factors of the growth of carbon nanotubes had been studied, which was to optimize the preparation process. In order to change the properties of carbon nanotube, the process of nitrogen ion beam bombardment of carbon nanotubes was also explored. To further optimize the performance of carbon nanotubes, the contact angle measure-ment, X-ray photoelectron spectroscopy (XPS), Laser Raman spectroscopy (LAMA-N), Fourier transform infrared spectrometry(FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to detect and analysis the microstructure of carbon nanotubes.The experimental results showed that:in the preparation of carbon nanotubes, the major factors affecting the growth of carbon nanotubes were temperature, catalyst and growth conditions. The reaction temperature played a major role in the growth of carbon nanotubes. The diameter of carbon nanotubes with the changing reaction temperature showed an upward trend, and the diameter tended to be uniform. The diameter reached to104nm at the temperature of860℃, but the diameter of CNTs decreased with the addition of temperature. At the temperature of900℃, the carbon tube diameter was reduced to78nm. The influence of catalyst concentration mainly through the iron film thickness to reflect, it affected the diameter of the carbon nanotubes size and thickness extent.In the preparation of nitrogen-doped carbon nanotubes, the reaction temperature also played a critical role. When the reaction temperature is950℃, the carbon nanotubes was very, very uniform, no less amorphous carbon and other impurities, and there was a uniform layer of carbon nanotube film on the substrate, the outer diameter of carbon nanotubes were concentrated in the50-100nm and the inner diameter in the10-20nm. The contact angle of the sample surface on carbon nanotubes was124.69°, which was judged to a hydrophobic material. XPS analysis results showed that the content of nitrogen atom on the sample surface was an upward trend with increasing temperature, the N/C on the sample surface reached to1/23, the percentage of the nitrogen atoms was4.06%, while the nitrogen atom binding energy increased to401.10eV. The results of TEM showed that the carbon nanotubes prepared by the method were nitrogen-doped carbon nanotubes.In the modification of carbon nanotubes by nitrogen ion beam bombardment, the content of nitrogen on the sample surface had increased, and the hydrophilicity of the carbon nanotubes showed a increasing trend, When the beam intensity was increased to15mA, the contact angle of the sample was72.64°, the percentage of nitrogen atoms on the sample surface increased to8.6%, while nitrogen atom binding energy was reduced to399.6eV. There were new polarity nitrogen functional group appear. The emergence of new polar functional groups.