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A new flexible nanostructure of [CoFe2O4/PVP]@[YAG:7 %Tb3+/PVP] magnetic-luminescent bifunctional coaxial nanofibers is fabricated successfully by electrospinning technology using a homemade coaxial spinneret. The morphologies, structures, and magnetic and luminescent properties of the final products are investigated by modern determination techniques. The results show that the coaxial nanofibers simultaneously provide better magnetic and luminescent properties than CoFe2O4/YAG:7%Tb3+/PVP composite nanofibers owing to the isolation of the YAG:7%Tb3+ luminescent nanofibers from the CoFe2O4 magnetic nanofibers. Furthermore, the luminescent characteristics and saturation magnetizations of the coaxial nanofibers can be tuned by adjusting the contents of luminescent and magnetic compounds. The formation mechanism of coaxial nanofibers is also presented. More importantly, the design concept and construction technology are of universal significance for the fabrication of other bifunctional coaxial nanofibers. [ABSTRACT FROM AUTHOR]

Flexible luminescent-electrical-magnetic trifunctional Janus nanofibers have been successfully fabricated through electrospinning technology by using specially designed parallel spinnerets. The terbium complex [Tb(ba)3(phen)] (BA=benzoic acid, phen=1,10-phenanthroline), polyaniline (PANI), and Fe3O4 nanoparticles (NPs) were incorporated into polyvinyl pyrrolidone (PVP) and electrospun into Janus nanofibers with [Tb(ba)3(phen)]/PVP as one strand of the nanofiber and PANI/Fe3O4/PVP as another. The morphologies and properties of the final products were investigated in detail by XRD, SEM, TEM, fluorescence spectroscopy, Hall effect measurement system, and vibrating sample magnetometry. The [[Tb(ba)3(phen)]/PVP]//[PANI/Fe3O4/PVP] Janus nanofibers, with an average diameter of 180 nm, simultaneously possess enhanced luminescent performance, electrical conduction, and magnetism. Fluorescence emission peaks of Tb3+ are observed in the [[Tb(ba)3(phen)]/PVP]//[PANI/Fe3O4/PVP] Janus nanofibers and assigned to the 5D4→5F6 ( λ=491 nm), 5D4→5F5 ( λ=544 nm), 7D4→5F4 ( λ=585 nm), and 5D4→7F3 ( λ=620 nm) energy-level transitions of Tb3+ ions; the 5D4→5F5 hypersensitive transition at λ=544 nm is the predominant emission peak. The electrical conductivity of Janus nanofibers reaches up to the order of 10−3 S cm−1. The luminescent intensity, electrical conductivity, and magnetic properties of Janus nanofibers can be tunable by adjusting the amounts of rare-earth complex, PANI, and Fe3O4 NPs present. This new type of luminescent-electrical-magnetic trifunctional Janus nanofiber holds potential for a variety of applications, including molecular electronics, microwave absorption, and future nanodevices, owing to their excellent fluorescence, electrical conduction, and magnetism. [ABSTRACT FROM AUTHOR]