BaTiO3@carbon/silicon carbide/poly(vinylidene fluoride-hexafluoropropylene) three-component nanocomposites with high dielectric constant and high thermal conductivity

Abstract

This work reports a new three-component composite which is consisted of dielectric carbon coated barium titanate hybrid particles (BT@C), thermal conductive silicon carbide nanoparticles (SiC NPs), and flexible poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP). The BT@C is synthesized via hydrothermal reaction of BT nanoparticles with glucose and further carbonized at 800 °C. The TEM images and Raman spectra reveal that the structure of carbon coating layer is high ordering graphitic carbon. Compared with the two-component BT@C/PVDF-HFP and SiC/PVDF-HFP composites, the three-component BT@C/SiC/PVDF-HFP composites show a positive synergistic effect of the two fillers in enhancing not only thermal conductivity but also dielectric constant. The results show that with the addition of 5.5 wt% and 10 wt% SiC NPs into BT@C-2(50 wt%)/PVDF-HFP composite, the thermal conductivity increases to 0.69 W m−1k−1 and 0.92 W m−1k−1 respectively (0.61 W m−1k−1 as control). For dielectric performance, the dielectric constant of BT@C-2(50 wt%)/PVDF-HFP increases from 80 to 1394 at 1 kHz with addition of 7.8 wt% SiC NPs. The dielectric constant is almost 158 times greater than that of pure PVDF-HFP (8.8, measured) and the dielectric loss tanδ is 0.9. These results show a good balance of dielectric performance. This method offers us a potential for the design and fabrication of polymeric dielectric composites which could be applied in electronic devices.