Dielectric properties and energy storage densities of poly(vinylidenefluoride) nanocomposite with surface hydroxylated cube shaped Ba0.6Sr0.4TiO3 nanoparticles

Abstract

Ceramic-polymer nanocomposites, consisting of surface hydroxylated cube-shaped Ba0.6Sr0.4TiO3 nanoparticles (BST-NPs) as fillers and poly(vinylidenefluoride) (PVDF) as matrix, have been fabricated by using a solution casting method. The nanocomposites exhibited increased dielectric constant and improved breakdown strength. Dielectric constants of the nanocomposite with surface hydroxylated BST-NPs (BST-NPs-OH) were higher as compared with those of their untreated BST-NPs composites. The sample with 40 vol % BST-NPs-OH had a dielectric constant of 36 (1 kHz). Different theoretical models have been employed to predict the dielectric constants of the nanocomposites, in order to compare with the experimental data. The BST-NPs-OH/PVDF composites also exhibited higher breakdown strength than their BST-NP/PVDF counterparts. A maximal energy density of 3.9 J/cm3 was achieved in the composite with 5 vol % BST-NPs-OH. This hydroxylation strategy could be used as a reference to develop ceramic-polymer composite materials with enhanced dielectric properties and energy storage densities.