Piezoelectric effect in nanofibers deposited with magnetic field assisted electrospinning using solutions with PVDF and Fe₃O₄ nanoparticles

Structural characterization of polymeric nanofibers of polyvinylidene fluoride (PVDF)

“…Some authors [30,40,41] have already described that the electrospinning process favors the appearance of the β-phase. With it in mind, it is possible to notice the presence of bands referring to the β-phase at 421 cm -1 , 840 cm -1 , and 1278 cm -1 in the spectrum [13,30,40] . The band observed at 799 cm -1 is designed as α-phase [12] .…”

“…Figure 6 shows the registered FTIR spectra of the sample. Vibrational bands at 611 cm -1 (CF 2 bending), 763 cm -1 (CF 2 bending and skeletal bonding) [10,38] , and 987 cm -1 were identified in the spectrum of fibers, which refer to the α-phase [13,30,40] . The characteristic bands of the β-phase, responsible for the piezoelectric properties, appear at 441 cm -1 , 510 cm -1 , 745 cm -1 , 840 cm -1 , and 1280 cm -1 .…”

“…Over the years, researchers related to the subject have shown that, due to their high surface/volume ratio and high performance, electrospun fibers could have great potential in various applications [19] . The properties of the materials used in the process can be promoted in the electrospun fibers, which can act, e.g., as chemical protective clothing [24] , biomedicine [25] , filtering process [26,27] , sensors [4,28] , electronic devices [26,29,30] , etc. However, for the transfer of this technology to industry and large-scale production, it has been necessary to overcome some limitations such as (i) low fiber deposition rate, (ii) production of fibers with controlled and consistent diameters, and (iii) the obtaining fibers free of defects inherent to the control of process parameters [31] .…”