Transports in blends of conducting polymers

We investigated the transport properties of solution-processed conductive polymer blends of polyaniline-(camhpor sulfonic acid), PANI-CSA, with insulating polymethylmethacrylate (PMMA), as a function of various volume fraction (ƒ) of PANI-CSA. Due to the phase separated morphology and the fibrillar geometry of percolating objects, a self-assembled PANI-CSA network in insulating matrix shows extremely low percolation threshold (ƒc ≈ 0.003). The characteristic metallic properties of pure PANI-CSA, such as positive temperature coefficient of resistivity at high temperature, linear temperature dependence of thermoelectric power, and frequency independent ac conductivity, are retained in PANI-CSA/PMMA blends down to ƒc. At low temperature, the hopping transports through the conducting polymer network depends on the volume fraction of PANI-CSA in blends and its network structure.