Impact of thermal treatment and magnetic field on the dynamic mechanical behavior of polyacrylonitrile nanofibers with embedded magnetic ferrite nanoparticles

Abstract

Electrospun ferrite–polymer nanofiber composites exhibit an exclusive combination of electronic and material properties and tailorable functionalities. An incorporation of (cobalt) ferrite nanofillers to the polyacrylonitrile (PAN) matrix was corroborated by X-ray diffraction, where the systematic and organized arrangement of inorganic components was achieved through non-covalent bonding upon electrospinning, as proven by the energy dispersive X-ray attached to scanning electron microscopy. These nanomaterials exhibit the intrinsic electronic characteristics of the polymers due to the π-electron system of the CN group with oxide particles, as revealed by Fourier transmission infrared spectroscopy. By applying an external magnetic field during dynamic mechanical measurements under tension, expecially for the PAN/CoFe₂O₄, remarkable increase in the glass transition (∼16 K) and activation energy (almost twice as high) along with a higher storage modulus are observed with the application of magnetic field in comparison to standard PAN nanofiber samples to be attributed to the magnetostrictive behavior of Co ferrite. The thermomechanical stability of the samples with undetectable weight loss was ascertained by thermogravimetric analysis. These results demonstrate that the nanofillers not only reinforce the polymer matrix but also introduce field-responsive mechanical characteristics, highlighting their potential in sensing, actuation, and smart material applications.