To investigate the contribution of the nano fillers in amplifying the number of charge carrier concentration in the system dielectric constant with silica content was studied at room temperature at three different frequencies. From the figure it can be observed that the variation of dielectric constant with silica content at room temperature follows the same trend as conductivity. This observation is an ample evidence of the fact that the ion motion and polymer chain movement are coupled. The observation further affirms that the increase in the number charge carriers is a major contributing factor in enhancing the conductivity.
Correlating with the results of FTIR investigations it may be concluded that the formation of bonds between nano SiO2–Starch or, nano SiO2–PVA play a vital role in constructing
the conductive pathways and the three dimensional network structure that facilitate the ionic motion. In addition increased interaction of starch with the bound water in the system may be factor that amplifies the number of charge carriers by accelerating the dissociation of
the salt and aggregates. Reduction in large scale heterogeneity of the system caused by the nano filler is another probable reason that increases dielectric constant and the conductivity of the system [31]. The variation of ionic conductivity with silica content at room temperature
establishes that Starch/PVA blend with glycerol, glutaraldehyde and fumed SiO2 can prove to be an efficient polymer system for realizing ionic conductivities 103 S/cm at ambient conditions. The decrease in dielectric constant at 4 wt% silica is attributed to the decrease in the number of charge carriers due to neutral pair formation and blocking of the conductive pathways due to agglomeration of nano fumed silica nanoparticles. The conductivity 103 S/cm could be achieved at 5 wt% of LiBr which is much low compared to several studies. This is another aspect of momentous significance in the present study