Preparation and electroactive properties of a PVDF/nano-TiO2 composite film

In the present study, poly(vinylidene fluoride) (PVDF)/nano-TiO2 electroactive film was prepared by coating a substrate with an acetone/DMF solution, which was evaporated at a high temperature (110 degrees C). The crystallisation behaviour, dynamic mechanical properties and electroactive properties of this PVDF/nano-TiO2 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 beta phase, the desired ferroelectric phase, was obtained by crystallising the mixed solution of nano-TiO2 and PVDF at 110 degrees C, while the film containing the alpha 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. TiO2 improved the mechanical properties and electroactive properties of the film. The results indicate that PVDF/nano-TiO2 composite films can be applied to the fabrication of self-sensing actuator devices. (C) 2010 Elsevier B.V. All rights reserved.