Vibrational Properties of Carbon Nanotubes

In comparison with SWNTs, DWNTs show some RBM bands in the low-frequency 170-350 cm region due to the inner wall tube breathing modes, and bands below 170 cm due to the outer tubes [138]. J.M.Benoit et al. have presented a detailed low-frequency Raman study of arc-discharge MWNTs. A comprehensive simulation of the Raman spectrum shows that the low-frequency spectrum of MWNTs is very sensitive to their internal diameter [139]. 

The first vibrational calculations concerning the IR active modes in SWNTs reported that the main absorption bands are localized at ca. 682, 806, 854, 956, 1033, 1095-1164, 1262, 1443, 1541, 1585, and 1730 cm and were all assigned [140]. According to the authors knowledge, until now, additional IR vibrations modes for the DWNTs and MWNTs have not been reported. 

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