Published online by Cambridge University Press: 15 April 1999
In this paper, a simple model classically used to describe electrical behavior in conducting polymers can take into account transport properties in polyaniline dopedwith two different counter-ions and in polyaniline-polystyrene blends. Conduction isMaynly limited by hopping or tunneling between polaronic conducting clusters. When thestructural disorder is less pronounced, a metallic contribution can occur near roomtemperature in series with the hopping/tunneling one. This heterogeneous picture usedfor unblended polyaniline can be applied to explain electrical blend properties abovethe percolation threshold when conduction occurs among completely connectedpolyaniline paths. Below the percolation threshold, the model has to take into accountan additional contribution due to a hopping mechanism between large disconnectedsegments of polyaniline. It is shown that thermoelectric power reflects essentiallythe metallic behavior of the conducting clusters.