Conducting polymers. VI. Effect of doping with iodine on the dielectrical and electrical conduction properties of polyacrylonitrile

摘要

The effect of doping of polyacrylonitrile (PAN) with iodine on the dielectical properties and ac conductivity as a function of temperature and frequency is investigated. Thermogravimetric analysis, TGA, and FTIR measurements show that PAN undergoes degradation starting at 523 K. Doping PAN with I_2 enhances the ac electrical conductivity σ_(ac) in the temperature range under investigation due to oligo-merization of the nitrile groups giving a conjugated polyimine. The thermal activation energy, A￡, is calculated for PAN and PAN/I_2 and found to be in the range 0.16-1.16 eV at 0.1 kHz. The correlated barrier hopping (CBH) conduction mechanism is found to be the dominant conduction mechanism for PAN and PAN/I_2 samples.