Effect of shell-layer thickness on dielectric properties in Ag@TiO ₂ core@shell nanoparticles filled ferroelectric poly(vinylidene fluoride) composites

The Ag@TiO ₂ core@shell nanoparticles filled ferroelectric poly(vinylidene fluoride) (PVDF)-based composites (0-3 connectivity) were prepared in order to study the effect of core@shell structure on dielectric permittivity in the Ag@TiO ₂/PVDF nanocomposites. The Ag@TiO ₂ core@shell nanoparticles were synthesized via a water-thermal meting route. Transmission electron microscope (TEM) images showed the nanoparticles were about 60-120 nm in diameter and the thickness of the shell layer was about 6-12 nm, which can be adjusted by changing the fabrication conditions. Results of dielectric measurements showed that the shell-layer thickness of the Ag@TiO ₂ core@shell nanoparticles played a key role in deciding the final values of the dielectric properties of the nanocomposites. The variation of dielectric properties of the nanocomposites with temperature also depends on the shelllayer thickness of the Ag@TiO ₂ core@shell nanoparticles.