Design and one-pot direct electrospinning construction of high-performance magnetic@conductive@fluorescent tri-coaxial microbelts and array

Multifunctional materials have more extensive applications than their counterpart single-functional materials due to their superior polyfunctions, among which fluorescent-conductive-magnetic (FCM) multifunctional materials have been extensively investigated for their unique performance and application value. However, the material properties may be degraded due to the adverse interactions among the fluorescent, conductive and magnetic materials with three different functions when they are directly blended. Hence, such adverse interactions brought by the direct contact of different functional materials should be avoided by designing and preparing unique structures. In this study, a one-dimensional (1D) tri-coaxial microbelt is innovatively designed, which can effectively separate and integrate different materials at the micro-level to obtain excellent macroscopic polyfunction. Generally, the preparation of tri-coaxial structure requires multistep procedures. To facilely construct the designed tri-coaxial microbelt, as a case study, a novel [CoFe2O4/polymethyl methacrylate (PMMA)]@[polyaniline (PANI)/PMMA]@[Tb(acac)3bpy/PMMA] (defined as [M@C@F]) tri-coaxial microbelts and arrays are synthesized through the one-pot direct electrospinning (ES) process. The tri-coaxial microbelts are assembled by the CoFe2O4/PMMA magnetic core layer, the PANI/PMMA conductive intermediate layer, and the Tb(acac)3bpy/PMMA insulated-fluorescent shell layer. It is the first time to integrate three different functions into the tri-coaxial microbelts and restrict three functions into three independent zones in the microbelt to shun adverse mutual interferences. The function of each layer can be regulated by adjusting the position and content of the three functional materials. Comparison with the control samples indicates that the property of the tri-coaxial microbelts array is directly impacted by structure and the arrangement modes of the building units. Hence, excellent macroscopic polyfunctions are obtained via designing and preparing microscopic partitioned building units and arranged modes. Array displays superior green fluorescence at 549 nm, tunable electrical conduction and magnetism. The new technique of one-pot direct construction of the tri-coaxial microbelts is significant and can be extended to for assemble other multifunctional materials. Moreover, the constructed [M@C@F] tri-coaxial microbelts and arrays have applications in various fields, such as micro-integrated circuits, microchips, and micro/nanodevices.