Effect of Solution Concentration on the Electrospray/Electrospinning Transition and on the Crystalline Phase of PVDF

Abstract

ABSTRACT

Coaxial electrospun nanofibers of poly(vinylidene fluoride)/polyaniline filled with multi-walled carbon nanotubes

“…Concentration of PVDF in the solution was kept at 12 wt%. To produce the blend's nanofibers , PANi was dissolved in DMF and the solution was filtered to remove nondissolved PANi. The concentration of PANi in the solution based on thermal gravimetric analysis (TGA) of nanofibers was found to be ∼8 wt%.…”

Formation of uniform PVDF fibers under ultrasound exposure in presence of anionic surfactant

“…Obtained average diameter of fibers for 2:3 DMF:Acetone mixture is around 750 nm while at lower acetone content, 1:1 DMF:Acetone, fibers have more narrow diameter distribution but larger average diameter which is around 900 nm. Taking into account low values and vicinity of solution conductivities for both mixtures (see Table 2), lower fiber diameter can be only attributed to the difference in viscosity of solutions [34,35]. Viscosity data for PVDF solutions at several DMF/Acetone mixtures are shown in Table 2.…”

Surface morphology and beta-phase formation of single polyvinylidene fluoride (PVDF) composite nanofibers

“…3b exhibits a high number of beads at the same concentration. The concentration of PVDF was reported widely as the most significant factor to minimize the beads in PVDF nanofiber [18,25]; however, the substantial difference in nanofiber size ( Figs. 1 and 2) and bead formation (Fig.…”

“…However, the increase in DMF/acetone ratio results in nanofiber with increased beads may be attributed to the incomplete solvent evaporation. Indeed, the high volatility of acetone increased the evaporation rate of the solution which causes the jet to dry faster and thus impeding the electrospun jet breaking up into droplets [25]. Also, the addition of acetone reduces the surface tension of the solution so that beaded fibers can be converted into smooth fibers [41].…”

“…Despite electrospinning method appears to be technically straightforward, processing variables are not well understood and optimized in order to fabricate PVDF nanofibers with the desired properties [21]. For instance, the effects of each individual electrospinning process parameter on the properties of PVDF nanofiber have already been reported [18,[22][23][24][25]. The interdependences of each processing parameter on nanofiber characteristics have not been studied, since the conventional model only involves changing one of the electrospinning process parameters while keeping the others fixed at certain values.…”