Distinctive Sandwich-Type Composite Film and Deuterogenic Three-Dimensional Triwall Tubes Affording Concurrent Aeolotropic Conduction, Magnetism, and Up-/Down-Conversion Luminescence.

Abstract

Compared to single functional materials, multifunctional materials with electrical conduction, magnetism, and luminescence are more attractive and promising, so it has become an important subject. A distinctive sandwich-type composite film (STCF) with dual-color up- and down-conversion luminescence, magnetism, and aeolotropic conduction is prepared by layer-by-layer electrospinning technology. Macroscopically, STCF is assembled by three tightly bonded layers, including a [polypyrrole (PPy)/poly(methyl methacrylate) (PMMA)]//[NaYF4:Yb3+, Er3+/PMMA] Janus nanobelt array layer as the first layer, a CoFe2O4/polyacrylonitrile (PAN) nanofiber nonarray layer as the second layer, and a Na2GeF6:Mn4+/polyvinylpyrrolidone (PVP) nanofiber nonarray layer as the third layer. This unique macropartition effectually confines conductive aeolotropy, magnetism, and luminescence in different layers. Microscopically, a Janus nanobelt is used as a construction unit to restrict the luminescent and conductive materials to their microregions, thus achieving highly conductive aeolotropy and green luminescence. The high integration of the micro-subarea and macro-subarea in the STCF can efficaciously avoid the mutual disadvantageous effects among different materials to obtain splendid polyfunctional performance. The conductive anisotropy and magnetism of the STCF can be adjusted by changing the contents of PPy and CoFe2O4. When the PPy content reaches 70%, the conductance ratio in the conductive direction to insulative direction is 108. The 2D STCF can be crimped by four different methods, and the 3D TWTs have the same excellent polyfunctional performances as 2D STCF. This unique design idea and construction technology can be applied to the preparation of other multifunctional materials to avoid harmful interference among various functions.