Dielectric properties and thermal conductivity of PVDF reinforced with three types of Zn particles

In this study, three types of Zinc (Zn) particles, i.e., the spherical Zn (s-Zn), flaky Zn (f-Zn), and metal–semiconductor Zn@ZnO core–shell structure, are incorporated in poly(vinylidene fluoride) (PVDF) to obtain high dielectric permittivity polymer. The morphological, dielectric properties and thermal conductivity of the composites are characterized. The results indicate that compared with the s-Zn/PVDF the Zn@ZnO/PVDF at lower filler loading exhibited obviously higher dielectric permittivity due to the duplex interfacial polarizations, and that the f-Zn/PVDF showed larger dielectric permittivity and thermal conductivity owing to f-Zn’s high aspect ratio facilitating the formation of bridges between themselves. Furthermore, the dissipation factors of the s-Zn/PVDF and Zn@ZnO/PVDF were still at low level owing to the presence of self-passivation layer or ZnO shell between Zn core and PVDF, leading to a high critical filler concentration, whereas, a noticeable variation in the dissipation factor for the f-Zn/PVDF is observed up to 12 vol.% f-Zn.