Intermolecular Interaction in Carbon Nanotube Ropes

Abstract

Using Raman spectroscopy we determined the van-der-Waals component of the low-frequency vibration in ropes of single-walled nanotubes at 171 cm À1 . While Raman peaks in this frequency range are commonly believed to correspond to the pure radial breathing mode of a single tube, our pressure and temperature-dependent measurements show that van-der-Waals contribution of the peak observed at 514.5 nm excitation is necessary to explain its large pressure coefficient of 9.7 cm À1 /GPa. Our results are consistent with the small elastic modulus predicted for nanotube ropes.

High Pressure Studies of the Raman-Active Phonons in Carbon Nanotubes

“…in Table 1, the results of published experiments and calculations known to us [21,[27][28][29][30][31][32][33][34]. For the highest frequency peak in the T band region, a linear or quadratic function of pressure has been fit to the data; i.e.…”

Strength of radial breathing mode in single-walled carbon nanotubes

“…Raman scattering is therefore often used to determine the diameter or diameter distribution in nanotube samples [2,3,4]. In detail, the relation between nanotube diameters in real samples and the radial breathing mode spectrum is more complicated, because of the resonances in the Raman process and additional force constants coming from the tube-tube vander-Waals interaction in bundled nanotubes [3,5,6]. Furthermore, the RBM eigenvector has a small non-radial component [7,8].…”

High Levels of Electrochemical Doping of Carbon Nanotubes: Evidence for a Transition from Double-Layer Charging to Intercalation and Functionalization

“…30,31 Last but not least, the Raman efficiency of the RBM in an individual SWNT increases with decreasing diameter. 32 The experimentally observed behavior of the RBM band implies that factors ii and iii have a prevailing influence because factor i alone would lead to an apparent blue shift of the band.…”