Electrospinning preparation and properties of magnetic-photoluminescent bifunctional bistrand-aligned composite nanofibers bundles

Fe₃O₄/PVP//Eu(BA)₃phen/PVP magnetic-photoluminescent bifunctional bistrand-aligned composite nanofibers bundles based on ferroferric oxide(Fe₃O₄) nanoparticles and europium complex Eu(BA)₃phen (BA = benzoic acid) were fabricated via electrospinning by employing a homemade parallel axial electrospinning setup with the side by side dual spinnerets for the first time. The structures, morphology, and properties of the as-prepared products were investigated in detail by X-ray diffraction, field-emission scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy (TEM), a fluorescence spectrometer, and a vibrating sample magnetometer. SEM analysis showed the average diameter of the individual-strand fiber of the bistrand-aligned composite nanofibers bundles was 200 ± 25 nm. TEM image demonstrated that Fe₃O₄ nanoparticles were only dispersed into one strand of the bistrand-aligned composite nanofibers bundles, and the average diameter of Fe₃O₄ nanoparticles was about 15 nm. Under the excitation of 274 nm ultraviolet light, Fe₃O₄/PVP//Eu(BA)₃phen/PVP bistrand-aligned composite nanofibers bundles exhibited red emissions of predominant peaks at 592 and 616 nm, which were respectively attributed to the ⁵D₀ → ⁷F₁ and ⁵D₀ → ⁷F₂ transitions of Eu³⁺ ions. The fluorescence intensity of the bistrand-aligned composite nanofibers bundles was higher than that of Fe₃O₄/Eu(BA)₃phen/PVP composite nanofibers, and was decreased with the increase of the amounts of Fe₃O₄ nanoparticles. The saturation magnetizations of the bistrand-aligned composite nanofibers bundles and the Fe₃O₄/Eu(BA)₃phen/PVP composite nanofibers were about equal when the two nanostructures contained the same mass ratios of Fe₃O₄ nanoparticles, but the saturation magnetizations of the bistrand-aligned composite nanofibers bundles were increased with the increase of the amounts of Fe₃O₄ nanoparticles. The new type Fe₃O₄/PVP//Eu(BA)₃phen/PVP bistrand-aligned composite nanofibers bundles have potential applications in many fields due to their superparamagnetism behavior and high fluorescence intensity. Meanwhile, the research results will provide a new method for the preparation of the other two components of polymer fibers.