Biomedical Engineering Reference
In-Depth Information
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(iv) A second observed mode (2450-2650 cm
) assigned to the
first overtone of the D-mode and often called
.
(v) A combination mode of the D-band and G-band between
2775-2950 cm
G
-mode
. Usually, the I (G-mode)/I (D-mode) peak
intensity ratio is used as figure of merit to assess the ranking
of order/disorder in the CNTs layers grown.
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Figure 9.7
Raman spectrum showing the main features of carbon
nanotubes: RBM, the D-band, the G-band, and G
-band.
Spectrum achieved from SWCNTs sample (diameter of
1.07 nm) mixed with KBr using an excitation laser with
energy of 1.16 eV (wavelength of 1064.5 nm). The sample is
produced by electric arc-discharge followed by air-oxidation.
Reprinted with permission from Elsevier [41].
FTIR spectroscopy is currently used to study the effects of the
chemical modifications of the CNTs dispersed in solution phase
on the band gaps of the semiconducting SWCNTs. Chen
.
[49] demonstrated that the reaction of the soluble SWCNTs with
dichlorocarbene led to the functionalization of the nanotube walls.
The IR spectrum of the CNT solution in the range from 700 to
1800 cm
et al
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shows typical features of the radial mode and tangential
mode by demonstrating the successfully occurred surface modi-
fication in the CNTs.
X-ray diffraction (XRD) analysis is a nondestructive method used
to achieve information on the spacing, the structural strain, and the
