Piezoelectric response of graphene-filled PVDF nanocoposites through piezoresponse force microscopy (PFM)

The piezoelectric properties of Poly(vinylidene fluoride) (PVDF) mainly depend on its most polar β-phase. In this work, we investigated through Piezoresponse Force Microscopy (PFM) the piezoelectric properties of PVDF composite films when we induce the formation of β-phase crystals adding graphene nanoplatelets (GNPs) without any chemical modification or poling. At first, we fabricated GNP-filled PVDF composite films by the solution casting method. Then, we investigated the piezoelectric response of different samples: neat PVDF, PVDF-based nanocomposites filled with 0.3 wt%, 0.5 wt% and 0.7 wt% GNPs . The morphology of the produced PVDF/GNP composites was investigated through field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). The β-phase formation was assessed through Fourier transform infrared spectroscopy (FT-IR) measurements.