Effect of graphene oxide on the ferroelectric properties of P(VDF-TrFE) (56/44)

Graphene oxide (GO) based poly (vinylidene fluoride-trifluoroethylene) P(VDF-TrFE) (56/44) nanocomposite films were prepared using solution casting. Differential scanning calorimetry results showed increase in the crystallinity at lower GO content up to 0.3 wt %, where the 0.3 wt % GO-copolymer showed ∼13 % higher crystallinity than the pure copolymer under similar annealing conditions. However, at higher GO content, the high aspect ratio GO sheets suppress the crystallization of the polymer, resulting in 3 % lower crystallinity than the pure copolymer. The dielectric permittivity of the GO-copolymer showed improvement, likely due to the interfacial interaction between GO and polymer dipoles and also due to the higher crystallinity. At 20 Hz, the dielectric permittivity increased from ∼14.5 for pure copolymer to ∼18 for 0.3 wt % GO copolymer. Similarly, electrical conductivity of the GO-copolymer increased with GO content; however, even at the 0.6 wt % content GO, the copolymer nanocomposites did not attain the percolation threshold and displayed an insulative behavior like the pure copolymer. The presence of GO improved the ferroelectric properties of the copolymer films by increasing the remnant polarization from 47 (mC/m²) for pure copolymer to 57 (mC/m²) for the 0.3 wt % GO-copolymer.