Dielectric properties of zinc oxide/low density polyethylene nanocomposites

ZnO/low density polyethylene (LDPE) nanocomposites with either homogeneous or controlled inhomogeneous dispersions of ZnO nanoparticles were prepared. The dielectric constants of the composites with filler concentrations up to 40 vol.% were measured and compared with the dielectric constants of conventional submicron size ZnO filled LDPE composite. The filler particles were coated with silane coupling agents and mixed with LDPE to take advantage of the high surface area of nanoparticles for the introduction of high dipole moment molecules to the composite. The effect of filler distribution on the dielectric constant was also examined and the observed differences are attributed to the differences in the two kinds of interfaces present: one formed between the touching ZnO particles and the other formed between LDPE and ZnO.