Piezoelectricity Assessment of PVDF-Based Ternary Composites Simultaneously Tuned via Electrostatic and Hydrogen Bonding Interaction

Tuning the polarity of poly(vinylidene fluoride) (PVDF) via interfacial interactions with fillers has been widely explored in the past few years. However, most of the past works dealt with a single type of interfacial interaction. In the present work, we investigate the simultaneous effect of electrostatic and hydrogen bonding interactions on the polarity and piezoelectricity of PVDF-based composites. For this purpose, ZnO with negative surface charges has been used to induce electrostatic interaction with −CH2 dipoles, and ZnSn(OH)6, having a lot of −OH groups, has been used to induce hydrogen bonding interaction with −CF2 dipoles of PVDF. The polar phase increases to ∼90% for the mixed filler-loaded composite, which was ∼83% for the single filler-loaded composites. This simultaneous effect has also significantly improved the piezoelectric output voltage of the corresponding piezoelectric nanogenerator to ∼30 V, up from ∼18 V for any single type of interaction. The positive effect of the mentioned simultaneous interactions in PVDF has also been further established via theoretical simulations. Considering both the effect of the polarity of the composites and the individual piezoelectricity of the fillers, the theoretical simulations, as well as the experiments, have proven that polarity plays the main dominating role in tuning the piezoelectric performance of PVDF-based composites loaded with smaller amounts of filler particles.