Experimental Investigation of Piezoelectricity of Near Field Electrospun PVDF Nanofibers

Abstract

In this paper, the roles of mechanical stretch and electric poling on phase transition and piezoelectric response of Poly (vinylidene fluoride) (PVDF) nanofibers during Near Field Electrospinning (NFES) are investigated. By adjusting applied voltage or speed of motion stage while keeping other parameters constant, PVDF nanofibers enduring different electric poling and mechanical stretch are prepared. The average fiber diameter is observed by scanning electron microscope (SEM). The crystal structure of the fiber is analyzed through Fourier Transform Infrared spectrum (FTIR) and X-Ray diffraction (XRD), and the β phase responsible for the piezoelectricity is calculated for the quantitative analysis. The piezoelectric response is investigated utilizing a home-made testing system. The experimental results show that the piezoelectric response increases although the β phase content remains almost the same under stronger electric poling. On the contrary, the piezoelectric response remains almost the same while the β phase content increases under stronger mechanical stretch. This indicates that electric poling resulted from electric field is the main reason for the piezoelectric performance of PVDF.