Insights into the optical, magnetic and dielectric properties of some novel polysulfone/NiFe2O4 composite materials

다국어 초록 (Multilingual Abstract)

Novel polysulfone (PSU)/NiFe2O4 nanocomposites with good magneto‐dielectric properties were prepared in a simple and cost‐effective manner. Nickel ferrite nanoparticles exhibit a cubic spinel phase without any impurity phases according to X‐ray diffraction characterization. Transmission electron microscopy images of the nanoparticles showed a tetragonal particle shape with average particle size of 17–30 nm. The thermal stability of PSU proved to remain unaffected by nanoparticle concentration in the composite material. The emission spectra of the PSU/NiFe2O4 nanocomposites present a broad emission band located at 370 nm due to free exciton recombination. The composites exhibit hysteresis loops of a ferrimagnetic nature and good dielectric properties. Coercivity value measured at room temperature is 20.64 and 24.98 Oe and the squareness (Mr/Ms) is 0.290 and 0.225 for both polymer composite samples (4 and 24 vol% Ni ferrite). The formalism of the dielectric loss has been used to estimate the dipolar relaxations expressed by γ‐ and β‐relaxation processes. The presence of Ni ferrite nanoparticles in the PSU matrix increases the activation energy of secondary relaxations, which means a reduction of the molecular mobility in the nanocomposites as compared to PSU. © 2018 Society of Chemical Industry
Polysulfone/NiFe2O4 nanocomposites with various contents of nickel ferrite nanoparticles (5, 10, 20 and 30%) were obtained. The structural, morphological and optical properties were investigated. The presence of NiFe2O4 enhanced the thermal stability of the composites. The composites exhibited hysteresis loops of a ferrimagnetic nature and good dielectric properties.