Development and characterisation of polyvinylidene fluoride-polyaniline films for piezoelectric power generation

Abstract

Piezoelectric polymer nanocomposites are prepared to improve the dielectric properties of polyvinylidene fluoride (PVDF) as micropower generators. Polyaniline (PANI) was chosen as a filler material to prepare the nanocomposites. PVDF-PANI nanocomposite films were prepared using the solvent cast method with different volume fractions of PANI varying from 0.04 to 0.06%. The films were then characterised for structural, mechanical and surface morphological properties using X-ray diffraction, differential scanning calorimeter, Raman spectra, Infrared spectra, tensile testing and scanning electron microscopy. X-ray diffraction analysis shows that the prepared PVDF-PANI films were in beta-phase. DSC scans indicate that the degree of crystallinity in PVDF-PANI has improved. Raman and Infrared spectrum further confirm the presence of beta-phase in PVDF-PANI film. Tensile properties of PVDF-PANI films show good mechanical properties. The surface feature shows that PANI is uniformly distributed in PVDF and also results in the disappearance of spherulites. The influence of volume fractions of PANI in PVDF on the dielectric properties were analysed. The results showed that the dielectric permittivity of PVDF-PANI (137.36) was much higher than that of PVDF (12). The sensitivity of these films were studied by the application of pressure, and it was observed that the voltage response of the film sensor is 12.4 V pk–pk, which is steady with the constant application of 1.85 kg weight. PVDF-PANI film sensor shows higher sensitivity with a longer period of time. These films were tested to use as micropower generators when coupled with supercapacitors.