Chemical Engineering Journal, Vol.284, 831-840, 2016
Flexible hollow nanofibers: Novel one-pot electrospinning construction, structure and tunable luminescence-electricity-magnetism trifunctionality
Novel photoluminescent-electrical-magnetic trifunctional flexible Tb(BA)(3)phen/PANI/Fe3O4/PVP (BA = benzoic acid, phen = phenanthroline, PAN! = polyaniline, PVP = polyvinylpyrrolidone) hollow nano-fibers were constructed by one-pot coaxial electrospinning process using coaxial spinneret. Very different from the traditional preparation process of hollow fibers via coaxial electrospinning, which need to firstly fabricate the coaxial fibers and followed by removing the core through high-temperature calcination or solvent extraction, in our present study, no core spinning solution is used to directly fabricate hollow nanofibers. The morphology and properties of the hollow nanofibers were characterized in detail by X-ray diffractometry, scanning electron microscopy, transmission electron microscope, N-2 adsorption-desorption measurement system, fluorescence spectroscopy, 4-point probes resistivity measurement system and vibrating sample magnetometry. The Tb(BA)(3)phen/PANI/Fe3O4/PVP hollow nanofibers, with outer diameters of ca. 238 nm and inner diameters of ca. 80 nm, exhibit excellent photoluminescent performance, electrical conductivity and magnetic properties. Fluorescence emission peaks of Tb3+ ions are observed in Tb(BA)(3)phen/PANI/Fe3O4/PVP hollow nanofibers and assigned to the D-5(4) -> F-7(6) (490 nm), D-5(4) -> F-7(5) (545 nm), D-5(4) -> F-7(4) (585 nm) and sal D-5(4) -> F-7(3) (621 nm) energy level transitions of Tb3+, and the D-5(4) -> F-5(5) hypersensitive transition at 545 nm is the predominant emission peak. The electrical conductivity of the hollow nanofibers reaches up to the order of 10(-3) S cm(-1). The luminescent intensity, electrical conductivity and magnetic properties of the hollow nanofibers can be tuned by adding various amounts of Tb(BA)(3)phen, PANI and Fe3O4 nanoparticles. The new-typed photolu minescent-electrical-magnetic trifunctional flexible hollow nanofibers hold potential for a variety of applications, including electromagnetic interference shielding, microwave absorption, molecular electronics and biomedicine. This design conception and synthetic strategy developed in this study are of universal significance to construct more advanced multifunctional hollow one-dimensional nanomaterials. (C) 2015 Elsevier B.V. All rights reserved.