BaTiO3 is studied as a typical ferroelectric material with high
dielectric permittivity, low dielectric loss and other excellent
ferroelectric properties[1]. Owing to the outstanding properties,
BaTiO3 has been widely applied in capacitors, sensors, nonvolatile
random access memory and many composites[2]. With their high
intrinsic dielectric permittivities, the nanostructured BaTiO3 particles,
such as spheres[3] or fibers[4], have also been employed as
dielectric fillers in polymer composites to improve the dielectric
behavior of the composites. The dielectric as well as geometric
(size, shape etc) properties of the BaTiO3 particles play a critical
role in determining the dielectric behavior of the polymer composites[5,6].
There have also been efforts in making three-phase
polymer composites filled with both BaTiO3 particles and
conductive fillers. The presence of BaTiO3 nanoparticles prevents
the conductive fillers from connecting into conducting paths,
giving rise to lower dielectric loss. Our recent results show that akind of three-phase polymer composite filled with BaTiO3 nanoparticles
and graphene nanopellets could be polarized up to
150 kV/mm without much increased leakage current[7]. Yet,
BaTiO3 nanofibers are considered more promising over their
spherical counterparts as dielectric fillers to improve the dielectric
strength of their composites with polymers under high electric
field. Due to their large aspect ratios and hence larger dipolar
moment along their longitudinal axis, BaTiO3 nanofibers are
capable of increasing the dielectric permittivity of polymer composites[8].
Recent studies further indicate that surface treatments of
BaTiO3 nanofibers leads to stronger interfaces between the
nanofibers and polymer matrix, giving rise to enhanced dielectric
breakdown strength of polymer composites[9]. Enhanced dielectric
strength of these BaTiO3 nanofibers-filled polymer composites
is attributed to the orientation of BaTiO3 nanofibers in directions
perpendicular to the external electric field. Both phase field
modeling[6] and finite element simulation[10] indicate that the
orientation of BaTiO3 nanofibers is favorable for mitigating the
electric field concentration in polymer matrix, which is caused by
the large differences in dielectric permittivity between the BaTiO3
(εr w 1000) and polymer matrix (εr w 2e3).
Electrospinning is one of the methods to fabricate onedimensional
materials. It is a convenient and versatile method
to produce fibers, for instance, polymer, ceramic and composite
fibers[11e14]. In this study, continuous BaTiO3 nanofibers are
prepared via electrospinning with solegel precursor.