Induced anisotropy in electrically modified Polymer/Ceramic nanocomposites

Polymer/Ceramic composites with controlled spatial distribution of fillers are synthesized, and the corresponding changes in their properties are studied. Using dielectrophoretic assembly we create anisotropic composites of aligned BaTiO3 particles in silicone elastomer, and study their electrical properties as a function of ceramic volume fraction, connectivity and composite morphology. We investigate these composites for a variety of electrical properties i.e. permittivity, d.c. conduction, dielectric breakdown and energy density. The energy density of these electric-field-structured composites is found to be highly dependent on the anisotropy present in the system. This study emphasizes the important role of conductivity, permittivity, and particularly local cluster distribution in controlling high field dielectric behavior. Designed anisotropy in dielectric properties can provide new paradigms for the development of high energy density materials and gain important insights into the mechanisms that control dielectric breakdown strengths and non-linear conduction at high fields in polymer/ceramic composites.