Direct electrospinning construction of nanocables with electrical conductive-magnetic core and insulative-photoluminescent sheath

Novel flexible luminescent-electrical-magnetic trifunctional nanocables have been successfully fabricated by specially designed coaxial spinnerets electrospinning technology. Europium complex Eu(TTA)(3)(TPPO)(2) (TTA = 2-thenoyltrifluoroacetone, TPPO = triphenylphosphine oxide), PANI and Fe3O4 nanoparticles (NPs) were respectively incorporated into polyvinyl pyrrolidone (PVP) and electrospun into nanocables with Fe3O4/PANI/PVP as core and Eu(TTA)(3)(TPPO)(2)/PVP as the sheath. The morphology and properties of the final products were investigated in detail by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), fluorescence spectroscopy, Hall effect measurement system and vibrating sample magnetometer (VSM). SEM observation indicates that the diameter of the nanocables is 414 +/- 13 nm. TEM analysis shows the core diameter is ca. 250 nm containing magnetic nanoparticles and polyaniline, and the sheath thickness is ca. 81 nm. Fluorescence emission peaks of Eu3+ ions in the [Fe3O4/PANI/PVP]@[Eu(TTA)(3)(TPPO)(2)/PVP] nanocables are observed and assigned to the energy levels transitions of D-5(0) -> F-7(0) (579 nm), D-5(0) -> F-7(1) (592 nm), D-5(0) -> F-7(2) (614 nm), and the D-5(0) -> F-7(2) hypersensitive transition at 614 nm is the dominant emission peak. The obtained nanocables possess better fluorescent intensity than their counterpart Fe3O4/PANI/Eu(TTA)(3)(TPPO)(2)/PVP composite nanofibers. The electrical conductivity of the core of nanocable reaches up to the order of 10(-3) S cm(-1). The luminescent intensity, electrical conductivity and magnetic properties of the nanocables can be tunable by adjusting various amounts of rare earth complex, PANI and Fe3O4 NPs. The [Fe3O4/PANI/PVP]@[Eu(TTA)(3)(TPPO)(2)/PVP] flexible luminescent-electrical-magnetic trifunctional nanocables have potential applications in molecular electronics, biomedicine, microwave absorption and display device owing to their excellent multifunctionality.