F-TiO 2 /P(VDF-HFP) hybrid films with enhanced dielectric permittivity and low dielectric loss

In this study, self-assembly flower-like TiO 2 (F-TiO 2 ) particles with an average diameter of 400 nm are synthesized via a facile one-pot solvothermal method. P(VDF-HFP)-based composites with F-TiO 2 particles of different volume ratio as fillers are prepared. Microstructure and thermal analyses confirm that F-TiO 2 does not change the crystallization process of the polymer matrix, but disrupts the crystallization degree of P(VDF-HFP). Dielectric properties measured at various frequencies and temperatures indicate that the addition of the F-TiO 2 fillers enhances the dielectric constant of the composites, while the dielectric loss and electric conductivity do not significantly increase. The dielectric permittivity of the polymer nanocomposites is enhanced by 200% over that of the P(VDF-HFP) matrix at a filler content of 20 vol% while maintaining a rather low dielectric loss (0.043 at 1 kHz). Especially, the F-TiO 2 /P(VDF-HFP) composites exhibit low electric conductivity (≤10 −11 S cm −1 ) at low frequencies. All the improved performances suggest an easy method to fabricate nanocomposites having potential electrical applications.