  Vibrational properties of composites based on single-walled carbon nanotubes
(SWNTs) and conducting polymers of the type polyaniline (PANI) and poly
(3,4-ethylene dioxythiophene) (PEDOT) are reported. For PANI-functionalized
SWNTs, the intensity increase of the Raman band at 178 cm-1, associated with
radial breathing modes of SWNTs bundles, indicates an additional roping of
nanotubes due to the presence of the polymer. The interaction of this composite
with NH4OH solution involves an internal redox reaction between PANI and SWNTs.
Thus, the polymer chain undergoes a transition from the semi-oxidized state
into a reduced one. The functionalization of SWNT side walls with PEDOT is
invoked as well.
