▎ 摘　　要

In the present work, the surface-modified graphene (SMG)/poly(vinylidene fluoride) (PVDF) fibrous membranes obtained from the electrospinning were treated by the hot pressing in the laminating mode to form the SMG/PVDF composites. The SMG was prepared by subjecting the graphene oxide to silane modification, NaBH4 reduction, and PVDF grafting in sequence. The successful surface modification of graphene was confirmed by TEM, XPS, Raman spectroscopy, FTIR, WAXD, and TGA. Furthermore, the structures of SMG/PVDF composites fabricated by the electrospinning-hot pressing method were studied by SEM, FTIR, and WAXD, which exhibited the well dispersion of SMG in the PVDF matrix. Finally, the investigation showed that the dielectric permittivities of SMG/PVDF composites increased with the SMG content, which were significantly higher than that of pristine PVDF. The dielectric permittivity of SMG (16 wt%)/PVDF composite (83.8) at 1000 Hz was found to be ten-fold that of the corresponding value of pristine PVDF (8.3) with a relatively low dielectric loss factor (0.34) and a relatively high thermal conductivity (0.679 W/mK).