CHARGE-TRANSPORT AND MAGNETIC-PROPERTIES IN POLYANILINE DOPED WITH METHANE SULFONIC-ACID AND POLYANILINE-POLYURETHANE BLEND

Charge transport in polyaniline protonated fully with methane sulphoni c acid (MSA) and polyaniline (MSA)-polyurethane [PANI(MSA)-PU] blend h as been investigated through measurements of temperature (T) and elect ric field (E) dependence of conductivity (sigma), temperature dependen ce of thermoelectric power and magnetic susceptibility and electron sp in resonance at room temperature. PANI(MSA) exhibits a three-dimension al variable-range hopping (VRH) type of conduction, which is not the c ase with HCl-doped PANI and the electric field dependence of its condu ctivity is also consistent with VRH behavior. The thermopower in PANI( MSA) shows metallic behavior. The blend follows a one-dimensional VRH type of conduction and the electric field dependence of its conductivi ty exhibits the Poole-Frenkel effect. The temperature-dependent magnet ic susceptibility measurements indicate the presence of Pauli and Curi e spins in both the samples. From electron spin resonance measurements the percentage of Lorentzian and Gaussian spins have been estimated. In PANI-MSA a larger number of spins are found to be delocalized. The conduction mechanism in PANI-PU blend is discussed in comparison to ot her commercial conducting polymer blends.