Influence of BaTiO3@TiO2 core-shell inclusions on dielectric properties of PVDF-based composites

The inclusion of ferroelectric ceramic particles into a polymer matrix increases the electric energy storing capability of the material, combining the high dielectric constant of the inclusions with the high breakdown field of polymers. The coating of the inclusions with a shell of binary oxide with a different dielectric constant, modifies the electric field distribution and tailors the final dielectric properties. PVDF-based composites containing BaTiO3 particles coated, by three different procedures, with a thin layer of TiO2 were prepared by solvent casting. The morphological and spectroscopic features of the BaTiO3@ TiO2 core-shell particles, their dispersion and the polymorphism of PVDF, were correlated to the dielectric properties. Gathered results show the influence of the morphological features of the core-shell particles on the final dielectric properties.