Effects of applied voltage on the morphology and phases of electrospun poly(vinylidene difluoride) nanofibers

Abstract

Electrospinning is a simple and flexible process in continuous fiber fabrication. We investigate the effect of applied voltage on morphology and phases of poly(vinylidene difluoride) nanofibers obtained using the electrospinning technique. Quantitative and qualitative analyses were performed employing multiple characterizations such as Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). The fiber diameter, affected by the spinning jet's deformation, has non-uniform distribution at low voltages (10-16 kV) and is uniform at higher voltages (20 kV). Fiber uniformity developed due to the increased tension, which shrank the Taylor cone. The highest electroactive fraction (F EA ) of phases was obtained for the smallest diameter fiber with an average diameter of 110 nm at an applied voltage of 20 kV. FTIR spectroscopy and XRD results indicate that the electric field raises the amount of F EA phase to 74% at the present working parameters. HRTEM analysis revealed that the crystallites are very small, with ⊍-phase showing a size of around 10 nm and ⊎-phase is only of nanometric scale. Results also show that the c-axis of ⊍-phase crystallites had a preferred orientation along the fiber axis. On the other hand, the c-axis of ⊎-phase had a preferred orientation perpendicular to the fiber axis, implying that the direction of crystal growth for the ⊍-phase and ⊎-phase was different.

Processes of Electrospun Polyvinylidene Fluoride-Based Nanofibers, Their Piezoelectric Properties, and Several Fantastic Applications

“…This is because with the continuous increase in voltage (greater than 18 kV), the flow rate also gradually increases, the evaporation time of the solvent is shortened, and the effective stretching of the NFs is reduced. The effect of voltage on the crystalline phase transition was also confirmed in the work of Nugraha et al [ 87 ], and the change in β phase is a key factor affecting the piezoelectric properties of PVDF.…”

“…When the voltage gradually increases, the large surface aperture becomes elliptical and the grooves become more numerous because the Taylor cone is stretched more rapidly, and the roughness decreases because it is less affected by the buckling instability, as shown in Figure 4 (1). In addition, the PVDF fiber under high voltage is more uniform, and the crystallinity of PVDF is improved [ 87 ]. In this process, the polymer solution is stretched to produce β phase due to the effect of the electric field.…”

Local analysis of crystalline phases and properties of poly(vinylidene fluoride) electrospun composites with BaTiO3 nanorods

“…74 As consistent with previous findings, all samples exhibited weak indications of γ-phase within the 1225-1230 cm −1 band. [74][75][76][77] Although all results showed the appearance of γ-phase formation, only in samples with 1% BT rods could the γ-phase formation be calculated. The result shows that adding 1% BT rods is the optimal point for forming the γ-phase.…”

Recent Progress on Structure Manipulation of Poly(vinylidene fluoride)‐Based Ferroelectric Polymers for Enhanced Piezoelectricity and Applications

“…Nugraha et al. also studied the effect of the spinning voltage on the content of β crystals, [ 121 ] and found that increasing the voltage could increase the content.…”

“…Drum speed, electric field, and flow rate are the next important factors that affect the percentage of the 𝛽 phase with variations of 6.3%, 5.9%, and 5.7% in the 𝛽 content, respectively. Nugraha et al also studied the effect of the spinning voltage on the content of 𝛽 crystals, [121] and found that increasing the voltage could increase the content.…”