Enhanced Electrical Properties of PVDF Thin Film by Addition of NaCl by Near-Electric-Field 3D Printing

Abstract

Polyvinylidene fluoride (PVDF) thin films with high β-phase content exhibit excellent piezoelectric and dielectric properties. In this work, PVDF–NaCl composite film with high β-phase content was prepared by near-electric-field three-dimensional (3D) printing. The mechanism of the influence of NaCl on the nucleation and phase transition of the PVDF thin films was revealed based on the synergistic effect of the electric field and salt addition. The composite films were characterized by scanning electron microscopy, fourier transform infrared spectroscopy, x-ray diffraction analysis, and measurements of electrical properties. The results showed that NaCl can increase the density of the membrane, while the β-phase content and dielectric properties of the PVDF composite membrane are positively correlated with the amount of NaCl added. The β-phase content reached a maximum value of 52.68% when the amount of NaCl added was 0.05% by weight. The dielectric constant of the PVDF composite film increased with increasing NaCl content. The electrical properties also indicated that PVDF composite film with higher NaCl content showed higher electrical output voltage, while the response voltage of the composite film with 0.05 wt.% NaCl was higher than that of pure PVDF film.