Microstructure and electrical properties of green electrospun PVDF-HFP nanofibers

Abstract

Currently, with the recent increase of concern on the environmental hazards, toxicity, chemical and toxic waste, there has been growing interest in “green solvents” as alternative solvents instead of toxicity solvents. Most of the research reported on the preparation of Poly (vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) by using N, N- dimethylformamide (DMF) as a solvent which is considered a cancerogenic substance. Alternatively, dimethyl sulfoxide (DMSO) will be selectively decided as a low toxicity solvent and not hazardous. In this research, the mixture solvents of acetone/DMSO which was used as a co-solvent for the excellent fabricated PVDF-HFP nanofibers by using the electrospinning technique. The PVDF-HFP nanofiber membranes with various solvent ratios of 60:40, 70:30 and 80:20, denoted as A6D4, A7D3, and A8D2, respectively. All nanofiber films were investigated and characterized on the morphology, dielectric properties, and percentage of crystallinity. As a result, the dielectric constant of nanofiber membranes increased with the acetone contents. The maximum dielectric constant is devoted to A6D4 at 10 Hz. The copolymers structure with a different solvent ratio was modified β-phase which significantly affected the bandwidth dielectric properties. These fabricated PVDF-HFP nanofibers with the difference in the solution mixture can tune the electrical properties and phase orientation, and those fabricated nanofibers can be promoted in terms of energy storage, energy conversion, sensors, and electrocaloric application.