AC conductivity of conjugated polymer onto self-assembled aligned carbon nanotubes

Abstract

This work focuses on the combination of the complementary properties of carbon nanotube (CNT) thin film and poly3-octylthiophene (P3OT), following a dielectric route to the characterization of a novel composite material. The structural and electrical characterization of a P3OT/CNTs hybrid system performed by X-ray diffraction, differential scanning calorimetry and a.c. impedance spectroscopy show interesting effects, including the tendency of the nanotube structure to nucleate crystal growth and substantial changes in the dielectric behavior of the polymer, due to the effect of the polymer on the nanotube conformation. Dielectric relaxation spectroscopy demonstrates that the crystallization of the polymer onto the nanotubes results into a different relaxation of the composite's electronic structure. The changes in the dielectric properties can be explained in terms of a reduced vibrational freedom of the polymer chains as a consequence of the intercalation of the polymer matrix into the nanotubes’ lattice.