Question

Solution calculate the diameter of the nanotube

Answer 1

The diameter of SWNT was calculated from the RBM wavenumber.
The figure below shows a Raman spectrum of a single-walled carbon nanotube (SWNT).
By Raman spectroscopy, the RBM, D-band and G-band peaks are observed from the low-wavenumber end as typical peaks.

 

RBM (Radial Breathing Mode): 100 to 300 cm-1, vibration at which the nanotube diameter contracts and expands
D-band: vicinity of 1350 cm-1, defect-derived peak
G-band: vicinity of 1590 cm-1, in-plane vibration of graphite

 

As the frequency of RBM is inversely proportional to a diameter, it can be used to determine the nanotube diameter.
D (nm) = 248/ω = 248/184 = 1.3 (nm)

Whereas Raman spectroscopy focuses on average values, SPM (Scanning Probe Microscopy) allows each diameter to be individually viewed.