Structural, AC and DC Electrical Transport Properties of Nano Titania - Polyacrylamide Composite Films

The microstructural features as well as the AC and DC electrical properties of titanium dioxide (titania or TiO2) nanoparticle (NP) filled polyacrylamide (PAM) composite films with filler level (FLs) Varied from 0.02 up to 19.5 Wt % were experimentally studied . SEM images revealed that the composite films with FLs equal to 0.02 and 0.40 Wt % (low FLs) showed homogeneous dispersion of spherical TiO2 NPs, whereas aggregation of the filler was observed at higher FLs. The XRD patterns of these composite films revealed an increase in their amorphousness at low FLs. The activation energy (E_a) determined from Arrhenius equation showed that the composite with FL equal to 0.40 Wt % exhibited the lowest value of E_a (equal to 0.84 eV). Dielectric study revealed that the composite film with FL equal to 0.40 Wt % exhibited the highest value bulk conductivity at room temperature (4.39×10^-6S m^-1 at 303 K). Hence, the composite sample with FL 0.40Wt %, along with pure PAM, were subjected to a detailed dielectric study at various fixed temperatures ranging from 303K up to 353K. The composite sample with FL 0.40 Wt % showed a maximum bulk conductivity of 1.12×10^-4 S m^{- 1}at temperature 353K, while it was 3.45×10^-8 S m^-1 for pure PAM at 303 K.