Synthesis of NiFe2O4 nanofibers by joint sol-gel and electrospinning technique

Abstract

In this study, electrospinning combined with sol-gel technique is applied in order to produce magnetic nickel ferrite (Ni-ferrite) nanofibers. The prepared Ni-ferrite gel was mixed with poly(vinylpyrrolidone) (PVP) solution which was used as a spinning aid to enable spinnability of the mixture. Structural and morphological characteristics of the as-spun ferrite gel/PVP composite web structure and calcinated Ni-ferrite nanofibers were analyzed using scanning electron microscopy (SEM). Phase composition analysis was carried out by Fourier-transform infrared (FT-IR) spectroscopy, X-Ray diffraction analysis (XRD) and 57Fe Mössbauer spectroscopy (MS). The obtained results suggest that the pure nanocrystalline NiFe2O4 dense mat to the almost coral-like structure of fibers with diameters ranging from hundreds of nanometers to few micrometers was obtained. The results of MS analysis revealed the existence of a crystallite size distribution within the material as well as the existence of a superparamagnetic fraction with very small crystallite sizes (<13nm). Magnetic behavior of the obtained material at elevated temperatures was also scrutinized using thermomagnetic measurements (TM) up to 800 °C.

Study of the spectroscopic, magnetic, and electrical behavior of PVDF/PEO blend incorporated with nickel ferrite (NiFe2O4) nanoparticles

“…Bands at 1648 cm −1 and 1385 cm −1 correspond to the -OH bending of absorbed hydrates. The Fe-O and Ni-O stretching modes are present at 574 cm −1 and 422 cm −1 , indicating the creation of NiFe 2 O 4 NPs [18,35]. For (85/15 wt/wt%) PVDF/PEO, according to previous literature [18,36,37], band at 1400 cm −1 corresponds to wagging modes of CH 2 , 1231 cm −1 attributed to CH 2 twisting mode of PEO.…”

Synthesis, characterization and magnetic investigation of Er-substituted electrospun NiFe2O4 nanofibers

“…2(a) revealed the gel/PVP Ni-ferrites nanofiber before calcination with micron to submicron diameters that displayed amorphous and smooth surface with uniform diameters by reason of homogenous interactions between polymer and inorganic phase. Although, the SEM images of Ni-ferrites nanofibers after calcination and removal of PVP depicted a dense and rigid structure due to impact of establishment Ni ferrite phase and thermally decompose the PVA with diameters ranging from hundreds of nanometers to few micrometers [28,29]. The deformation in appearance of nanofiber were happened through shrinking the polymer during the initial phase of calcination.…”