Significantly enhanced dielectric property in PVDF nanocomposites flexible films through a small loading of surface-hydroxylated Ba_0.6Sr_0.4TiO₃nanotubes

Abstract

Polymer composite flexible films with high dielectric constant are highly desirable in electronic and electrical industry. Higher loading of the ceramic fillers is usually needed in order to realize high dielectric constant. However, such composites exhibit low breakdown strength and poor mechanical and processing properties. In this work, by incorporating high aspect ratio surface-hydroxylated Ba0.6Sr0.4TiO3 nanotubes (BST NT) prepared via electrospinning into a polyvinylidene-fluoride (PVDF) matrix, PVDF nanocomposite flexible films with high dielectric constant have been successfully obtained. The nanocomposite containing 10 vol% BST NT-OH has a dielectric constant of 48.2 at 1 kHz, which is 6.1 times higher than that of the pure PVDF (7.9). The dielectric properties of the composites are closely related to the combined effects of the surface modification, large aspect ratio, high surface area and paraelectric polarization behavior of the BST NT.