Structure and electrical properties of the oriented polyaniline films

The structure of oriented polyaniline (PANI) films were characterized by elemental analysis, FTIR, XPS, SEM, and X-ray diffraction, and their electrical properties were measured as a function of the protonation state, elongation ratio, temperature, and applied pressure. A maximum conductivity at room temperature for oriented PANI films can be achieved up to 500 s/cm with conductivity anisotropy as high as 20:1. The temperature dependence of conductivity for both unoriented and oriented films at 77-300 K and applied pressure of 0-11.4 kbar is consistent with the 3-D variable-range hopping model; however, the hopping barrier of oriented films is one order magnitude lower than that of unoriented films. The mechanism of enhanced conductivity for oriented PANI films is discussed.