Effect of sodium niobate (NaNbO₃) nanorods on β-phase enhancement in Polyvinylidene fluoride (PVDF) polymer

Ferroelectric nanocomposite thin films of Polyvinylidene Fluoride (PVDF) having 0 to 15 wt% of Sodium Niobate (NaNbO₃) nanorods, were prepared by solution casting method. Sodium Niobate nanorods were prepared by hydrothermal method. In the present work, it has been shown that the polar crystalline β-phase of PVDF, which is responsible for the piezoelectric property, enhances piezo properties from 52 to 75% by adding appropriate quantity of NaNbO₃ nanorods into the PVDF matrix without any additional mechanical and electrical treatment. The structural properties of nanocomposite films are analyzed by x-ray diffractometer (XRD) measurements and polar crystalline β-phase has been analyzed by Fourier transform infrared spectroscopy (FTIR). The composite films synthesized from 15 wt% loaded NaNbO₃ in PVDF showed remnant polarization (P_r) is 0.016 89 μC/cm² at an electric field of 150 kV cm⁻¹, generates maximum output voltage of 3.34 V and short circuit current 0.503 μA by repetitive finger imparting pressure. The power so generated is sufficient to drive micro watt power consuming device. It has been shown that NaNbO₃ nanorods not only facilitate the alignments of dipoles in PVDF but also increase the piezoelectric properties of the nanocomposite due to inherent piezoelectric property of NaNbO₃ nanorods. (paper)