Influence of nanoparticle size on nucleation of electroactive phase and energy storage behaviour of zinc ferrite/ poly(vinylidene fluoride) nanocomposite

Abstract

The incorporation of different size of nanoparticles in polymer matrix plays a dominating role in determining the overall structural, microstructural and electrical properties of the fabricated composites. In this paper, an investigation was done in order to establish the effect of incorporating different size of zinc ferrite (ZF) nanoparticles in poly(vinylidene fluoride) (PVDF) matrix. The incorporated spherical ZF nanoparticle induced nucleation of electroactive phases in PVDF matrix by means of electrostatic interaction between the surface charge of the filler and the dipoles of PVDF. The fraction of nucleated electroactive phases is strongly dependent on the size of the nanoparticles. There is a critical size of the nanoparticle, below which the nucleation efficiency of the filler diminishes as it may be swelled by the polymer macromolecules. On the other hand, if the filler size is too large, there is a possibility of formation of mixed conformation of polar and nonpolar phase. Further, this behaviour was correlated with the electrical response of composite where nanoparticle with the critical radius incorporated PVDF composite, exhibited maximum dielectric and ferroelectric property. Finally, a number of participating dipoles of polymer chain interact with ZF nanoparticle of different size were calculated by a model analysis and were represented schematically.