Syntheses, characterization, luminescent and magnetic properties of polymer bifunctional fibers containing terbium complexes and Fe3O4 nanoparticles

Abstract

The combination of electrospun nanofibers and nanoparticles is opening up potential in the field of bifunctional materials. Herein, polystyrene (PS, Mw ≈ 260, 000), polyvinyl pyrrolidone (PVP, Mw ≈1, 300, 000), and poly(methyl methacrylate) (PMMA, Mw ≈ 350, 000) bifunctional fibers containing Tb(acac)₃phen complexes (acac: acetylacetone, phen: 1,10-phenanthroline) and Fe₃O₄ nanoparticles (NPs) were synthesized by single-fluid electrospinning method. The structure of bifunctional microfibers was characterized by x-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy spectrum (EDAX) and infrared spectrum (IR). The average diameters of PS, PVP and PMMA bifunctional fibers are 1.65, 0.313 and 0.571 μm, respectively. The TEM images indicated that Fe₃O₄ NPs were successfully incorporated into bifunctional fibers. No absorption peaks of terbium complexes and Fe₃O₄ NPs can be seen in the IR spectra of bifunctional fibers. The luminescent and magnetic properties of bifunctional fibers were also investigated. Due to the change of ligands environment, the main excitation peaks blue shifted about 5–8 nm in the bifunctional fibers. Bifunctional fibers exhibited characteristic emission of Tb³⁺ ions. The polymers have no effect on the fluorescence lifetimes of terbium complexes. All bifunctional fibers were soft ferromagnetic. In addition, mechanical performances of these nanofibers were also studied. The maximum stress, strain corresponding to the maximum stress and elastic modulus of sample PVP-Fe-Tb is the largest, which indicates that the tensile performance of sample PVP-Fe-Tb is the best.