Electrospinning assembly of 1D peculiar Janus nanofiber into 2D anisotropic electrically conductive array membrane synchronously endued with tuned superparamagnetism and color-tunable luminescence

Abstract

Brand-new coaxial nanocable//nanofiber typed Janus nanofibers array membrane with tuned anisotropically electrical conduction, superparamagnetism and color-tunable luminescence has been prepared via electrospinning technology using a homemade coaxis//monoaxis spinneret and rotary drum as collector for the first time. As constitutional and electrically conductive unit for fabricating the array membrane, each one-dimensional (1D) peculiar Janus nanofiber consists of a half side of [Fe3O4/PVP]@[Tb(BA)3phen/Eu(BA)3phen/polyvinyl pyrrolidone (PVP)] with luminescent-superparamagnetic bifunctionality and the other half side of polyaniline (PANI)/PVP possessing electrically conductive functionality, and all of Janus nanofibers are aligned along with the same direction to form two-dimensional (2D) array membrane. The electrical conductivities along with the length direction and diameter direction (two perpendicular directions) of the Janus nanofibers in the array membrane are respectively high and low, leading to the electrically conductive anisotropy of the array membrane. Because [Fe3O4/PVP]@[Tb(BA)3phen/Eu(BA)3phen/PVP] as insulative units are used and inserted into the insulative direction of the array membranes to further block the movement of electrons, the largest conductivity ratio between length and diameter direction of the nanofibers for the array membrane reaches up to six orders of magnitude which is the highest conductivity ratio between the two perpendicular directions for nanofibrous membrane. Furthermore, the electrically conductive anisotropy of Janus nanofibers array membrane can be tunable by adjusting the amount of PANI. Besides, the Janus nanofibers array membrane is simultaneously endued with excellent and tunable superparamagnetism and photoluminescence. More importantly, the design idea and manufacture technique for the novel Janus nanofibers array membrane afford a facile approach for the fabrication of multifunctional nanomaterials-formed membranes.