Fabrication and comprehensive investigation on structural, morphological and electrical properties of polyvinylidene fluoride–nickel oxide nanocomposite thin films

This study is mainly centered on augmenting the β-phase content in polyvinylidene fluoride (PVDF) films by adding nickel oxide (NiO) for sensors and actuators applications. PVDF–NiO nanocomposite films with varying concentration of NiO were fabricated by simple sol–gel casting technique. The impact of NiO nanofiller on physical, structural, morphological and electrical properties of PVDF–NiO nanocomposite films were investigated by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR) and current–voltage (I–V characteristics) measurements. The XRD pattern show the semi-crystalline structure of PVDF–NiO nanocomposite films and possesses crystalline α and β phases. The estimated structural parameters such as crystalline size, micro strain and dislocation density have also been estimated from the XRD data. XRD and FTIR spectra of PVDF–NiO nanocomposite films confirm the reduction in the intensities of α phase with the dominance of electroactive β-phase as compare to pristine PVDF. As a result, the β-phase content increases and crystallinity also increase from 52% (for pristine PVDF) to 66% (7 wt% NiO). SEM images showed the uniform distribution of NiO particles within the PVDF pattern with the increase in porosity which enhances the ionic conductivity. The significant increase in the ionic conductivity is also analyzed by I–V characteristics which make this nanocomposite suitable for miniaturized electronic devices.