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

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 degrees 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%)/PVDFHFP composite, the thermal conductivity increases to 0.69 W m(-1) k(-1) and 0.92 W m(-1) k(-1) respectively (0.61 W m(-1) k(-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 tans 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.