Abstract
Conducting polymer polyaniline and insulating polymer polycarbonate composites have been prepared. Electrical conductivity can be controlled in a wide range (more than 15 orders of magnitude) by a small amount of polyaniline. This characteristic can be explained by a percolation model. That is, at the threshold concentration, the electrodes must be bridged by a conducting channel of polyaniline. The percolation threshold and critical exponent of the conductivity parallel to the film surface are different from those perpendicular to the film surface. This suggests the anisotropy of conductivity in the composite. The conductivity of a high polyaniline concentration composite is found to be stable up to 160° C.