Enhanced dielectric performance of P(VDF-HFP) composites filled with Ni@ polydopamine@BaTiO3 nanowires

Dielectric polymer nanocomposites have been attracting increasing attention because of their wide range of applications in electronics industry. To improve their dielectric properties, incorporating conducive fillers and ceramic fillers into the polymer matrix is considered to be an effective solution. Here, Ni nanoparticles (about 50-90 nm) were decorated onto the surface of polydopamine (PDA) coated BaTiO3 nanowires to synthesize Ni@ polydopamine@BaTiO3 nanowires (Ni@PDA@BT NWs, also denoted as NPB) with different Ni loading amount The nanowires were then added into poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) matrix and composite films were prepared. The dielectric performance of composite films is largely enhanced owing to the microcapacitor effect and interfacial polarization effect induced by Ni nanoparticles. This enhancement can be improved by increasing the loading amount of Ni. Crystallization behavior of the films were also investigated. With 20 vol% of Ni@PDA@BT NWs added, the dielectric constant of the composite film reaches 48.4 at 1 kHz, in contrast to 29.5 for 20 vol% of BT and 10.6 for pristine P(VDF-HFP). And the dielectric loss tangent remains at a low level of 0.23 at 1 kHz. These composite films exhibit potential for applications in flexible electronic devices and electrical systems.