Monitoring oxidation of multiwalled carbon nanotubes by Raman spectroscopy
Article first published online: 11 APR 2007
Copyright © 2007 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy
Special Issue: Raman Spectroscopy on Nanomaterials
Volume 38, Issue 6, pages 728–736, June 2007
How to Cite
Osswald, S., Havel, M. and Gogotsi, Y. (2007), Monitoring oxidation of multiwalled carbon nanotubes by Raman spectroscopy. J. Raman Spectrosc., 38: 728–736. doi: 10.1002/jrs.1686
- Issue published online: 29 MAY 2007
- Article first published online: 11 APR 2007
- Manuscript Accepted: 28 NOV 2006
- Manuscript Received: 24 AUG 2006
Multiwalled carbon nanotubes (MWCNTs) were oxidized in air and acids while varying the treatment time and/or temperature. The goal of this approach was to create the highest density of carboxyl groups with moderate sample loss, which is necessary for nanocomposite applications. In situ Raman experiments allowed real-time observation of the structural changes in MWCNTs upon oxidation. The ratio of the Raman intensities of the D and G bands was used to estimate the concentration of defects. It was found that while an oxidation for 6 h in H2SO4/HNO3 provided the strongest effect, a ‘flash oxidation’ in air (15 min at 550 °C) also leads to an efficient functionalization in a cost-effective and environmentally friendly way. Transmission electron microscopy, Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis and electrophoretic mobility analysis were used to study the oxidized nanotubes. Copyright © 2007 John Wiley & Sons, Ltd.