1 PHYSICAL PROPERTIES OF ZnO/PVA NANOCOMPOSITE FILMS

Nano-sized zinc oxide (ZnO) was synthesized by sol-gel method, and mixed with polyvinyl alcohol (PVA) to produce nanocomposite films. X-ray diffraction (XRD) revealed that the average particle size of ZnO is about 26 nm and its original structure remains unaltered in the PVA matrix. Scanning electron microscopy (SEM) was used to observe the morphology and dispersion of ZnO on the surface of the PVA films. The results of differential scanning calorimetry (DSC) showed that both thermal stability and degree of crystallinity of pure PVA were reduced by the addition of ZnO nanoparticles. Dielectric constant ( ') and ac conductivity (ac) of all samples were measured within temperature and frequency ranges of 300-468 K and 10 kHz-2 MHz, respectively. The behavior of ac(f) for pure PVA, as well as composite films indicated that the conduction mechanism was correlated barrier hopping (CBH). The results from this work were discussed and compared with those of previous studies of PVA composites