4.5 Conclusions
Raman spectra of graphite, single-walled, and multi-walled carbon nanotube
(SWCNT and MWCNT, respectively) materials were recorded using three different
excitation wavelengths. The G-bands of SWCNTs were found to have a noticeable
asymmetry at each wavelength and, therefore, were fitted taking three/four peaks
into account using two different line shape functions. The low wavenumber component of the G-band was fitted with a Breit-Wigner-Fano (BWF) and the other
two/three components with a Lorentzian line shape function. The presence of both
BWF and Lorentzian features in the Raman profiles of the G bands of the SWCNTs
together with the observed changes of line positions and shapes point to a mixture
of semiconducting and metallic CNTs in the CNT bundles. The values of the
apparent Young’s modulus of the SWCNT and MWCNT materials were calculated
using an empirical relationship recently published [36]. These calculations yielded
the values 1.39, 1.13 and 0.15 TPa for the SWCNTs and MWCNTs, respectively.
Thus, the SWCNTs materials have a larger apparent Young’s modulus, which goes
along with a higher crystallinity compared to the MWCNTs.
Acknowledgements AKO is grateful to the Alexander von Humboldt Foundation for the award
of a research fellowship. The authors would like to express sincere thanks to Prof. B. P. Asthana
and Dr. A. Srivastava for the MWCNT material and suggestions to initiate this work.
References
1. Kroto HW, Heath JR, O’Brien SC, Curl RF, Smalley RE (1985) C60: Buckminsterfullerene.
Nature 318:162–163
2. Ijima S (1991) Synthesis of carbon nanotubes. Nature 354:56–58
3. Kruss S, Hilmer AJ, Zhang J, Reuel NF, Mu B, Strano MS (2013) Carbon nanotubes as
biomedical sensors. Adv Drug Deliv Rev 65:1933–1950
4. Zaporotskova IV, Boroznina NP, Parkhomenko YN, Kozhito LV (2016) Carbon nanotubes:
sensor properties. A review. Mod Electron Mater 2:95–105
5. Iannazzo D, Piperno A, Pistone A, Grassi G, Galvagno S (2013) Recent advances in carbon
nanotubes as delivery systems for anticancer drugs. Curr Med Chem 20:1333–1354
6. Dalton AB, Collins S, Munoz E, Razal JM, Ebron VH, Ferraris JP, Coleman JN, Kim BG,
Baughman RH (2003) Super-tough carbon-nanotube fibres. Nature 423:703–703
7. Bokobza L (2012) A Raman investigation of carbon nanotubes embedded in a soft polymeric
matrix. J Inorg Organometallic Polym 22(3):629–635
8. Baibarac M, Baltog I, Lefrant S (2011) Recent progress in synthesis, vibrational
characterization and applications trend of conjugated polymers/Carbon nanotubes composites.
Curr Org Chem 15:1160–1196
9. Bose S, Khare RA, Moldenaers P (2010) Assessing the strengths and weaknesses of various
types of pre-treatments of carbon nanotubes on the properties of polymer/carbon nanotubes
composites: a critical review. Polymer 51:975–993
4 Material Analysis Using Raman Spectroscopy
135
Raman spectra of graphite, single-walled, and multi-walled carbon nanotube
(SWCNT and MWCNT, respectively) materials were recorded using three different
excitation wavelengths. The G-bands of SWCNTs were found to have a noticeable
asymmetry at each wavelength and, therefore, were fitted taking three/four peaks
into account using two different line shape functions. The low wavenumber component of the G-band was fitted with a Breit-Wigner-Fano (BWF) and the other
two/three components with a Lorentzian line shape function. The presence of both
BWF and Lorentzian features in the Raman profiles of the G bands of the SWCNTs
together with the observed changes of line positions and shapes point to a mixture
of semiconducting and metallic CNTs in the CNT bundles. The values of the
apparent Young’s modulus of the SWCNT and MWCNT materials were calculated
using an empirical relationship recently published [36]. These calculations yielded
the values 1.39, 1.13 and 0.15 TPa for the SWCNTs and MWCNTs, respectively.
Thus, the SWCNTs materials have a larger apparent Young’s modulus, which goes
along with a higher crystallinity compared to the MWCNTs.
Acknowledgements AKO is grateful to the Alexander von Humboldt Foundation for the award
of a research fellowship. The authors would like to express sincere thanks to Prof. B. P. Asthana
and Dr. A. Srivastava for the MWCNT material and suggestions to initiate this work.
References
1. Kroto HW, Heath JR, O’Brien SC, Curl RF, Smalley RE (1985) C60: Buckminsterfullerene.
Nature 318:162–163
2. Ijima S (1991) Synthesis of carbon nanotubes. Nature 354:56–58
3. Kruss S, Hilmer AJ, Zhang J, Reuel NF, Mu B, Strano MS (2013) Carbon nanotubes as
biomedical sensors. Adv Drug Deliv Rev 65:1933–1950
4. Zaporotskova IV, Boroznina NP, Parkhomenko YN, Kozhito LV (2016) Carbon nanotubes:
sensor properties. A review. Mod Electron Mater 2:95–105
5. Iannazzo D, Piperno A, Pistone A, Grassi G, Galvagno S (2013) Recent advances in carbon
nanotubes as delivery systems for anticancer drugs. Curr Med Chem 20:1333–1354
6. Dalton AB, Collins S, Munoz E, Razal JM, Ebron VH, Ferraris JP, Coleman JN, Kim BG,
Baughman RH (2003) Super-tough carbon-nanotube fibres. Nature 423:703–703
7. Bokobza L (2012) A Raman investigation of carbon nanotubes embedded in a soft polymeric
matrix. J Inorg Organometallic Polym 22(3):629–635
8. Baibarac M, Baltog I, Lefrant S (2011) Recent progress in synthesis, vibrational
characterization and applications trend of conjugated polymers/Carbon nanotubes composites.
Curr Org Chem 15:1160–1196
9. Bose S, Khare RA, Moldenaers P (2010) Assessing the strengths and weaknesses of various
types of pre-treatments of carbon nanotubes on the properties of polymer/carbon nanotubes
composites: a critical review. Polymer 51:975–993
4 Material Analysis Using Raman Spectroscopy
135