Silver nanoparticles–deposited sub-micro sized BaTiO3/PVDF composites: greatly increased enhanced constant and effectively suppressed dielectric loss

Abstract

Silver (Ag) nanoparticles deposited sub–micro sized BaTiO3 particles (µBT) were fabricated as hybrid particles (Ag@µBT) to promote the dielectric response in a poly(vinylidene fluoride) (PVDF). The dielectric constant (ε′) of the Ag@µBT/PVDF composites continuously increased as the volume fraction (f Ag@µBT) increased, while the loss tangent (tanδ) was effectively suppressed. The ε′∼173.49 was obtained in the composite with f Ag@µBT=0.49, while a low tanδ was achieved (0.024), which was close to 0.021 for the PVDF. The Ag@µBT hybrid particles played essential roles in increased ε′ and inhibited conductive pathways, resulting in a low tanδ. The ε′ increased slightly, whereas tanδ changed significantly over the measured temperature range. Furthermore, ε′ was fitted with the effective medium percolation theory model. Therefore, the significantly improved dielectric properties were attributed to the high ε′ value of the µBT phase and interfacial polarization between the conductive Ag and insulating phases (i.e. µBT and PVDF).