Spectroscopic studies were performed on carbon
nanotubes including single-walled carbon nanotubes
(SWNTs) and double-walled carbon nanotubes (DWNTs).

First, we followed the reported method to obtain the
individually dispersed SWNTs with the assistance of
surfactants in aqueous phase. The absorption and
fluorescence spectra of this surfactant/SWNTs
suspension were captured and the species
distribution for the semiconducting tubes was
assigned as well. Afterwards, we studied how the
surfactant/SWNT suspension is affected by sonication
temperature, centrifugation time, pH, and the...