Flexible special-structured Janus nanofiber synchronously endued with tunable trifunctionality of enhanced photoluminescence, electrical conductivity and superparamagnetism

We report a facile and highly-effective method to assemble luminescent–magnetic–electrical tri-functionalities into the special-structured Janus nanofibers. Novel and brand-new flexible special-structured [coaxial nanocable]//[nanofiber] Janus nanofibers synchronously endued with tuned and enhanced luminescent–magnetic–electrical trifunctionality have been prepared via electrospinning technology using a homemade coaxis//monoaxis spinneret for the first time. Each special-structured Janus nanofiber consists of a coaxial nanocable made of Fe₃O₄/PVP core and Eu(BA)₃phen/PVP shell as a half side with luminescent–magnetic bifunctionality and polyaniline (PANI)/PVP nanofiber as the other half side with electrically conductive functionality. The special and novel Janus nanofiber not only can guarantee effective separation of Fe₃O₄ nanoparticles (NPs) and PANI from rare earth complex, but also ensure the continuity of PANI in the matrix. It is satisfactorily found that the luminescent intensity of the novel special-structured Janus nanofibers respectively reaches up to 10 and 22 times higher than those of counterpart conventional [nanofiber]//[nanofiber] Janus nanofibers and composite nanofibers owing to its peculiar nanostructure. Compared with the counterpart conventional Janus nanofibers of two independent partitions, coaxial nanocable is used as one side of the special-structured Janus nanofiber instead of nanofiber, and three independent partitions are successfully realized in the special-structured Janus nanofiber, thus the interferences among various functions are further reduced, leading to the fact that more excellent multifunctionalities can be obtained. The novel Janus nanofibers possess excellent fluorescence, superparamagnetism and electric conductivity, and further, these performances can be respectively tunable via modulating the respective Eu(BA)₃phen, Fe₃O₄ and PANI contents. The design philosophy and the construction technique for the special-structured Janus nanofibers are of universal significance for the fabrication of other multifunctional Janus nanofiber of various performances.