Enhanced dielectric properties of poly(vinylidene fluoride-co-hexafluoropropylene) nanocomposites using oriented nickel nanowires

Abstract The alignment of fillers in polymer matrix plays an important role in the dielectric properties of composite materials, but there are currently limited ways to effectively control the orientation of the fillers. In this paper, nickel nanowires (Ni NWs) with natural ferromagnetism were aligned under the external magnetic field during the fabrication process of poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) based nanocomposite. Subsequently, orientation effects of Ni NWs, including the in-plane, through-plane and random patterns along the electric field orientation, on the dielectric performance of P(VDF-HFP) nanocomposites were investigated. The results showed that the dielectric properties of Ni NWs-P(VDF-HFP) nanocomposites were related to the anisotropy of Ni NWs. The highest dielectric constant of polymer nanocomposites with the 1.3 vol% Ni NWs reached to 41 at 1 kHz when the orientation of nanofiber was parallel to electric field, which is 274% higher than that of unaligned one and is 513% higher than the neat polymer. In addition, the nanocomposites kept the low dielectric loss. The results can be explained by combining the percolation theory, micro capacitor model and interfacial polarization theory. The finding provides a new method to prepare the nanocomposite dielectric materials with fillers arrangement. On the other hand, it is meaningful to in-depth understand the effect of fillers arrangement on the dielectric properties of composite materials.