Effect of PEO crystallization on dielectric response of PVDF/PEO@IL coaxial electrospinning nanofiber films

Abstract

AbstractIn this study, core‐shell structured nanofibers (P/E/@IL), in which the blend of poly(ethylene oxide) (PEO) and ionic liquid (IL) acted as core and poly(vinylidene fluoride) (PVDF) acted as shell layer, were prepared by coaxial electrospinning in order to explore the effect of PEO crystallization on the ionic conductivity and dielectric property. For comparison, the blended spinning fibers of PVDF, PEO, and IL (abbreviated as P/E/IL) were also fabricated. It can be observed that the incorporation of IL dramatically improves the dielectric constant () of P/E/@IL composites. However, the tan δ also exhibits a sharp increase with increasing content of IL due to the ion conduction, whereas compared with blended films, the PEO and IL in the core layer exhibit a more positive effect on suppressing the tan δ of film via PEO crystallization. Through melting the PEO lamellae in core, it can be found that the ion conduction as well as tan δ were enhanced. Based on these results, it is confirmed that the ion transport stemmed from IL was suppressed by the PEO lamellae. As the content of IL reached up to 20 wt%, tan δ of the composites with PEO lamellae was reduced to half of P/E/IL spinning fibers.