temperature. In both types of motions, i.e., charge carriers
through the polymer backbone system and hopping of electron
between localised sites can be affected by the frequency and
also the aniline concentration positively.
The Cole–Cole or Nyquist plot of the complex impedance
Z=Z/+ Z//, (Real (Z) versus Im (Z)) at room temperature
for D2–D4 is shown in Fig. 9 for frequency range of 50 kHz
to 1 MHz. Theoretically, an ideal Nyquist impedance plot features
a semicircle over the high frequency region and a linear
part in the low frequency range. The plot for three
PANI(DBSA)/PVA blends shows similar trend like ideal
Nyquist impedance plot. The D2 blend with low aniline content
has the larger semicircle amongst the three, which represents
higher interfacial charge-transfer resistance and is
attributed to the poor electrical conductivity of the materials,
whereas D4 has the smallest radius of semicircle indicating
low resistance and high conductivity of the material. And the
straight line of the Nyquist plot in the lower frequency region
corresponds to the resistance resulting from ion diffusion.
The temperature dependent conductivity for sample D4 for
five different frequencies conducted is shown in Fig. 10. From
the plot it is seen that at high temperature region for all frequencies
there is no change in conductivity. However the difference
in the conductivity values can be seen in low
temperature region. From the plot it is also clear that the mode
of conductivity is different for low temperature and high temperature
for all the frequency ranges.