Effect of shell-layer thickness on dielectric properties in Ag@TiO2 core@shell nanoparticles filled ferroelectric poly(vinylidene fluoride) composites

The Ag@TiO2 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@TiO2/PVDF nanocomposites. The Ag@TiO2 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@TiO2 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 shell-layer thickness of the Ag@TiO2 core@shell nanoparticles. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim