Engineering of core@double-shell structured Zn@ZnO@PS particles in poly(vinylidene fluoride) composites towards significantly enhanced dielectric performances

Polymeric dielectrics with high dielectric permittivity (epsilon ') and low loss have momentous applications in energy storage devices. In this study, to concurrently improve the epsilon ' and restrain the loss of original Zn (Zinc)/poly(vinylidene fluoride, PVDF), the core@double-shell structured Zn@ZnO(zinc oxide)@PS(polystyrene) particles were prepared and composited with the PVDF. The impacts of the dual shells on the dielectric properties and polarization mechanism of composites were explored by fitting the experimental data with a Havriliak-Negami (H-N) equation. The Zn@ZnO@PS/PVDF exhibit remarkably higher epsilon ' in comparison to the raw Zn and Zn@ZnO fillers owing to the induced multiple polarizations originating from the combined contributions of the alpha relaxation of PVDF, slow interparticle polarization and fast intraparticle polarization. More importantly, the epsilon ' of the composites remarkably increases with the PS shell' thickness, while the loss is still kept at rather low levels owing to the PS shell' barrier effect on long-range charges migration. So, the introduction of the PS shell synchronously promotes both the interparticle and intraparticle polarizations in the Zn@ZnO@PS/PVDF composites toward enhanced dielectric properties. The developed strategy opens a novel path to the design and fabrication of polymer composites with desirable dielectric performances for applications in electronics and electrical industry.