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 beta-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 mu A, and electric power of 7892.2 nW. After the electric poling, the piezoelectric performance was further enhanced to 11.69 V, 20.56 mu A, and 1115.2 nW, which was high enough to light up a small LED bulb after rectification.