Preparation of magnetoelectric composites by nucleation of the electroactive β-phase of poly(vinylidene fluoride) by NiZnFe2O4 nanoparticles

Abstract

Composites consisting on poly(vinylidene fluoride), PVDF, and nano-size NiZnFe2O4 ferrites have been prepared by solution casting. The addition of NiZnFe2O4 nucleates the polar β-phase of PVDF, leading to magnetoelectric composites suitable for sensor and actuator applications. The amount of β-phase increases with increasing amount of nanoparticles up to filler concentrations of ~5%wt. For this concentration almost 90% of the crystalline phase of the polymer is in the electroactive β-phase. The nucleation occurs due to epitaxial crystallization at the nanoparticle surface, leading to variations in the crystallization kinetics and to the stabilization of the β-phase.