Abstract

Polymer-ceramic composites having polyvinylidene fluoride (PVDF) matrix filled with nanocrystalline barium titanate (BT) and multiwalled carbon nanotubes (MWNTs) were prepared by sonicated solution mixing method. The dielectric permittivity and electrical conductivity of such hybrids were measured over a wide range of frequencies. The results showed that the dielectric permittivity of PVDF/BT 50/50 composite at room temperature increases from ∼ 94 to ∼ 620 at 1 kHz by adding a small amount (2.5 vol. %) of nanotubes. Moreover, the dielectric permittivity of this hybrid composite tended to increase with increasing temperature and reached an apparent maximum value of 780 at 122 °C. The excellent dielectric performance of the composite was analyzed in terms of the percolation and dielectric relaxation concepts.

Keywords: Dielectric permittivity, conductivity, nanocomposites, carbon nanotubes, barium titanate