Fabrication and Characterization of Piezoelectric Composite Nanofibers Based on Poly(vinylidene fluoride-co-hexafluoropropylene) and Barium Titanate Nanoparticle

Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)-based composite nanofibers containing different barium titanate (BaTiO3) nanoparticle contents of 10–60 wt% were fabricated by an efficient electrospinning. The piezoelectric performance of PVDF-HFP/BaTiO3 composite nanofibers under a periodic compressional pressure of ∼20 kPa was investigated by considering the BaTiO3 content and the electric poling. The X-ray diffraction patterns revealed the presence of piezoelectric tetragonal BaTiO3 nanoparticles in the composite nanofibers with PVDF β-form crystals. The SEM images demonstrated that the BaTiO3 nanoparticles were dispersed uniformly in the composite nanofibers at relatively low loadings of 10–20 wt%, but they formed aggregates at high loadings of 30–60 wt%. The piezoelectric performance of the composite nanofibers increased with the BaTiO3 content up to 20 wt% and decreased at higher BaTiO3 contents of 30–60 wt%, which results from the trade-off effect between the piezoelectric performance and the dispersibility of BaTiO3 nanoparticles in the composite nanofibers. Accordingly, the composite nanofibers with 20 wt% BaTiO3 exhibited maximum piezoelectric outputs such as voltage of ~9.63 V, current ~0.52 µA, and electric power of ~7892.2 nW. After the electric poling, the piezoelectric performance was further enhanced to ~11.69 V, ~20.56 µA, and ~1115.2 nW, which was high enough to light up a small LED bulb after rectification.