Enhancement of piezoelectric properties for [poly (vinylidene fluoride)/barium zirconate titanate] nanocomposites

Abstract.

Poly (vinylidene fluoride) / barium zirconate titanate nanocomposite samples with the formula [x (PVDF) / (1 - x) BZT] (where x = zero, 0.2, 0.4, 0.6, 0.8 and 1) are prepared using the hot pressing method. The BZT is prepared using the tartrate precursor method. The properties of these nanocomposites are characterized by X-ray diffraction (XRD), scan electron microscope (SEM), transmission electron microscope (TEM) and Fourier transformed infrared (FTIR) at room temperature. The XRD patterns indicate that the average crystallite size ranges from 7.5 to 23.8nm. The grain size is estimated from SEM micrograph and lies between 263 and 186nm, whereas the average crystallite size has a distribution between 14 and 70nm from TEM images. The FTIR spectra illustrate the absence of any absorption band related to the ($\gamma$) phase, but the absorption bands characteristic for ($\alpha$), and ($\beta$) phases of PVDF are observed. The fraction of the ($\beta$) phase of PVDF increases by increasing the BZT content, which is very useful in industrial applications, such as sensors, actuators and transducers. The high value of the piezoelectric coefficient $d_{33}$ is measured for the PVDF/BZT nanocomposites.