The effect of core-shell BaTiO3@SiO2 on the mechanical and dielectric properties of PVDF composites

Abstract

In this study, polymer composite films were prepared by the solution casting method using ceramic filler barium titanate (BT) to enhance the mechanical and dielectric properties of polyvinylidene fluoride (PVDF). A silicon dioxide (SiO2) shell was coated on BT surface by hydrolysis reaction of tetraethyl orthosilicate (TEOS) at different concentrations in order to provide a strong interface between PVDF and BT. The influence of SiO2 coating on morphology, structure, thermal, tensile and dielectric properties of composites were investigated compared to neat PVDF. The results of analyses show that SiO2 is successfully coated on BT and that the ceramic filler enhances the tensile and dielectric properties of the composites. At low BT concentrations (5 and 10 vol.%) the tensile strength and Young modulus are improved compared to neat PVDF. For films having a high content of SiO2, in particular, coated BT high values, such as 24.8 at 10(2) Hz are found for the dielectric constant, which is greatly improved by almost 2.3 times compared to neat PVDF. Properties, such as flexibility and thermal stability, are well retained in the prepared composites.