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. (author)