Low dielectric loss and weak frequency dependence of dielectric permittivity of the CeO2/polystyrene nanocomposite films

Nanocomposite films with cerium oxide (CeO2) nanoparticles as functional fillers and polystyrene (PS) as polymer matrix were prepared using solution casting method. Physical properties including both weak frequency dependence of dielectric permittivity and low dielectric loss were experimentally discovered in the CeO2/PS nanocomposite films. To improve the dielectric properties of films further, the surface of CeO2 nanoparticles was treated by H2O2 to increase the homogeneity of the nanocomposite film, which was confirmed by scanning electron microscopy (SEM) results. Furthermore, it was found that both the filler size and the filler volume fraction played a role on the dielectric properties of the nanocomposite films.