The effect of processing conditions on the crystal structure and electroactive properties of poly(vinylidene fluoride)/ multi-walled carbon nanotubes nanocomposites

Abstract

The most common approaches for the fabrication of poly(vinylidene fluoride)(PVDF)/ multi-walled carbon nanotubes(MWNTs) nanocomposites involve solution crystallization and melting crystallization methods. In this study, PVDF/ MWNTs nanocomposites with varied contents of MWCNTs (up to 0.3wt.%) were prepared via solution crystallized at 80 °C, solution crystallized at 120 °C and melting at 200 °C. The effect of processing conditions on the crystal structure, morphology, dielectric and ferroelectric properties of PVDF with the presence of MWNTs was investigated. It is seen that crystallization temperatures and the concentrations of MWNTs have a synergetic effect of on the crystal phase and crystallinity of PVDF. Higher crystallization temperatures appeared to be detrimental to the dispersion of MWNTs in PVDF matrix, however, it was advantage to the growth of crystals and leaded to a higher degree of crystallinity. Lower crystallization temperatures favored the dispersion of MWNTs in PVDF matrix, which can effectively promote the formation of polar crystalline β-phase of PVDF. In addition, MWNTs at relatively low content (<0.1 wt.%) can disperse well in PVDF matrix in different approaches, resulting in high content of -phase and enhancements in dielectric and ferroelectric properties.