Enhanced thermoelectric performance of single-walled carbon nanotubes/polyaniline hybrid nanocomposites

Abstract

Hybrid nanocomposites containing carbon nanotubes (CNTs) and ordered polyaniline (PANI) have been prepared through an in situ polymerization reaction using a single-walled nanotube (SWNT) as template and aniline as reactant. TEM, SEM, XRD, and Raman analyses show that the polyaniline grew along the surface of CNTs forming an ordered chain structure during the SWNT-directed polymerization process. The SWNT/PANI nanocomposites show both higher electrical conductivity and Seebeck coefficient as compared to pure PANI, which could be attributed to the enhanced carrier mobility in the ordered chain structures of the PANI. The maximum electrical conductivity and Seebeck coefficient of composites reach 1.25 ×104 S m-1 and 40 μV K -1, respectively, and the maximum power factor is up to 2 × 10-5 W m-1 K-2, more than 2 orders of magnitude higher than the pure polyaniline. This study suggests that constructing highly ordered chain structure is a novel and effective way for improving the thermoelectric properties of conducting polymers. © 2010 American Chemical Society.