Event Information
Carbon nanotubes; synthesis and control their properties
- Abstract:
This project synthesizes double- and few-walled carbon nanotubes (DWNTs, FWNTs) in high yield by chemical vapor deposition (CVD) over a Mo-Co catalyst supported on magnesium oxide particles using a combustion method. The vertical CVD system was developed to increase the yield and improve the quality of carbon nanotubes (CNTs) as well as to demonstrate the effect of the feed gases, such as carbon monoxide and methane. Furthermore, a new combustion catalyst was created to reduce the harmfulness of the original combustion catalyst, due to its extremely low density. This new catalyst is denser than the original one, but it keeps its ability to produce CNTs with high yield. In order to maximize the yield, oxidation temperature was optimized. This project also studied comparison of DWNTs and FWNTs in the Raman spectra. While DWNTs’ Raman data agreed previous Raman data in other groups, Raman spectra of FWNTs was carefully investigated by comparing with DWNTs’. Lastly, FWNTs were separated by centrifugation in the density gradient solution. This project demonstrated the ability of sorting CNTs by their mechanical properties, such as different diameter and the number of walls. UV-vis, Raman spectra and TEM images supported this ability.
Preliminary Examination Seminar
Student Exams Seminar