Enhanced dielectric properties of conductive-dielectric composites by reducing particle size and core@shell method

Abstract

Based on the percolation threshold theory of conductive-dielectric composites, the dielectric constant can be improved more by adding a certain mass fraction of conductive particle into polymer matrix. However, the dielectric loss increases with the increasing mass fraction of conductive particle. In this paper, conductive Polyaniline (PANI) with different particle sizes is utilized to illustrate that reducing particle size can improve the dielectric properties. The dielectric constant is increased from 319 to 540, and dielectric loss is decreased from 2.34 to 0.85 when PANI with smaller particle size is used. Moreover, PANI coated with an insulating surfactant layer can further improve the dielectric properties, the experimental results show that the dielectric constant of the composite could be more than 1000, while the dielectric loss is 0.35 at 1[Formula: see text]KHz.