Significantly enhanced dielectric properties of ag-deposited (In1/2nb1/2)0.1ti0.9o2/pvdf polymer composites

Abstract

The enhanced dielectric permittivity (ε′) while retaining a low loss tangent (tanδ) in silver nanoparticle−(In1/2Nb1/2)0.1Ti0.9O2/poly(vinylidene fluoride) (Ag-INTO/PVDF) composites with dif-ferent volume fractions of a filler (fAg-INTO) was investigated. The hybrid particles were fabricated by coating Ag nanoparticles onto the surface of INTO particles, as confirmed by X-ray diffraction. The ε′ of the Ag−INTO/PVDF composites could be significantly enhanced to ~86 at 1 kHz with a low tanδ of ~0.044. The enhanced ε′ value was approximately >8-fold higher than that of the pure PVDF polymer for the composite with fAg-INTO = 0.5. Furthermore, ε′ was nearly independent of frequency in the range of 102–106 Hz. Therefore, filling Ag−INTO hybrid particles into a PVDF matrix is an effective way to increase ε′ while retaining a low tanδ of polymer composites. The effective medium percolation theory model can be used to fit the experimental ε′ values with various fAg-INTO values. The greatly increased ε′ primarily originated from interfacial polarization at the conducting Ag na-noparticle–PVDF and Ag–INTO interfaces, and it was partially contributed by the high ε′ of INTO particles. A low tanδ was obtained because the formation of the conducting network in the polymer was inhibited by preventing the direct contact of Ag nanoparticles. © 2021 by the authors.