Abstract:
A proton-conducting polymer electrolyte system based on starch doped ammonium
nitrate �N03) has been prepared through solution casting method. The ionic
conductivity for the starch- NH4N03 was conducted over a wide range of frequency
between 50Hz and 1MHz and at temperatures between 303K and 37 3K. Fourier
Transform Infrared (FTIR) spectroscopy showed that the complexation has occurred.
The sample containing 25wt% ammonium nitrate exhibit the highest conductivity at
room temperature at 2. I 9x10-
6
S·cm-
1
for sample SAN25 studied using
Electrochemical Impedance Spectroscopy (EIS). The conductivity by various
temperatures obey Arrhenian rule and found to influence the proton conduction.
Calculations using the Rice and Roth model provide number of mobile ions, 17,
diffusion coefficient, D and ionic mobility,µ. The transport parameter of the samples
shows that the increase in conductivity is due to the increase in the mobility of ions,
diffusion coefficient where the value of the cation diffusion coefficient, D+ at
5.99xl011
cm
2
s-
1
obtained is higher than the value of the cation diffusion coefficient,
12
D_ at l.70xl0-
2
1
and the value of the cation ionic mobility,µ+ at 2.29xI0-
cm
s-
09
cm
2
Y-
1
s1
is
higher
than
the
value
of
the
anion
ionic
mobility,µ_
at
7.08x
1011
cm
2
Y-
1
s-
1
.The Transference Number Measurement was performed to correlate the diffusion
phenomena to the conductivity, a behaviour of starch-NH4N03 polymer electrolyte.
Therefore, this study had proven that the starch-ammonium nitrate polymer electrolyte
is a proton conductor.