Preparation and electroactive properties of a PVDFano-TiO_2 composite film

摘要

In the present study, poly( vinylidene fluoride) (PVDF)ano-TiO2 electroactive film was prepared by coating a substrate with an acetone/DMF solution, which was evaporated at a high temperature (110 ℃). The crystallisation behaviour, dynamic mechanical properties and electroactive properties of this PVDFano-TiO_2 electroactive film were investigated. The cross-section and surface of the film were observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) results showed that the film containing the PVDF β phase, the desired ferroelectric phase, was obtained by crystallising the mixed solution of nano-TiO_2 and PVDF at 110℃, while the film containing the a phase was obtained from the crystallisation of the pure PVDF solution at the same temperature. It was found that the storage modulus, the room-temperature dielectric constant and the electric breakdown strength of the composite films were much higher than those of a pure PVDF film. TiO_2 improved the mechanical properties and electroactive properties of the film. The results indicate that PVDFano-TiO_2 composite films can be applied to the fabrication of self-sensing actuator devices.