Highly thermally conductive PVDF-based ternary dielectric composites via engineering hybrid filler networks

Abstract Thermally conductive ternary poly (vinylidene fluoride) (PVDF)-based dielectric materials were fabricated via engineering the filler networks using hexagonal boron nitride (hBN) nanosheets and surface functionalized silicon carbide (f-SiC) nanowires. The hBN nanosheets and f-SiC nanowires synergistically improved the thermal conductivity of the composites, in a way that parallelly oriented f-SiC nanowires bridged by the hBN nanosheet networks. The ternary composites with 20 wt% hBN nanosheets and 26 wt% f-SiC nanowires exhibited a high thermal conductivity of 1.41 W/mK, about 5.9 times of that of neat PVDF. In addition, the ternary composites showed superior dielectric permittivity, while maintaining a low loss at 1 kHz. The presence of f-SiC nanowires contributed to the interfacial polarization between the fillers and PVDF matrix, resulting in the increased dielectric permittivity. Meanwhile, low dielectric loss could be maintained due to the isolation of f-SiC nanowires by insulating hBN nanosheets and PVDF matrix.