Electrical conductivity of a single conducting polyaniline nanotube

We report the electrical properties of a single conducting polyaniline nanotube measured by a standard four-terminal technique. Camphor sulfonic acid doped polyaniline nanotubes were self-assembled by a template-free method. The directly measured conductivity of the single polyaniline nanotube is very high (similar to31.4 S/cm), and its temperature dependence follows the three-dimensional variable range hopping model. However, the bulk conductivity of the polyaniline nanotube pellets is much smaller than the nanotube itself (only 3.5x10(-2) S/cm) and ln rho(T) is linear in T-1/2, which is due to the large intertubular contact resistance. These results will help us to understand the conduction mechanism in conducting polymers. (C) 2003 American Institute of Physics.