Local Piezoresponse of Electrospun PVDF/BaTiO3 Nanocomposite Fibers

Nanocomposite fibers of poly(vinylidene fluoride) (PVDF) with embedded BaTiO3 nanoparticles were produced in the form of oriented meshes by rotating collector electrospinning. Local piezoelectric response was probed on single nanofibers by non-contact piezoresponse force microscopy (NC-PFM). The value of local d33 piezoelectric coefficient found on the nanofiber is consistent with literature data for the semicrystalline polymer containing the ferroelectric crystallographic beta-phase. Piezoresponse amplitude is not uniform along the fiber, probably due to the twisting direction of ferroelectric polarization. Decrease of piezoresponse is generally found in correspondence of nanoparticles, with occasional spots of increased response. Such finding can be explained by a tradeoff between drop of electric field intensity, due to the high dielectric constant of BaTiO3, and piezoelectric coefficients of the two materials, along with the mutual orientation of polar axes.