Construction Of Flexible Sandwich-Structured Composite Film Simultaneously Endowed With Double Electrically Conductive Anisotropy-Magnetism-Photoluminescence Multifunctionality

In recent years,anisotropic conductive films（ACFs）have been widely used in high-tech fields due to their many advantages,which has aroused great interest among workers in the field of materials science.Three kinds of ACFs have been developed.Type Ⅰ ACF has been widely used in the electronics industry,while Type Ⅱ and Type Ⅲ ACFs are still in the stage of laboratory research.Meanwhile,with the rapid development of nanoscience and technology,single-function nanomaterials can no longer meet the growing technical demands.Nanomaterials of multifunction at specific dimensions will be of great significance to the development of nanoscience and nanotechnology.Therefore,the development of new multifunctional nanomaterials is a research topic of great value.In this dissertation,based on the type Ⅲ ACF,four kinds of flexible sandwich-structured composite films were constructed by electrospinning technology.The first layer of the sandwich-structured composite film is a type Ⅲ anisotropic conductive film having left and right parts and the building unit of both parts is Janus nanoribbon consisted of a conductive side and a fluorescent-insulating side.The left part is perpendicular to the right part along the length orientation of the nanoribbon to achieve double anisotropic conductance.The second and the third layers of the sandwich-structured composite film respectively are nanofibers with magnetism and fluorescence to realize the corresponding functions.The as-prepared samples include{[<Tb（BA）₃phen/PMMA>//<PANI/PMMA>]⊥[<Tb（BA）₃phen/PMMA>//<PANI/PMMA>]}/[Fe₃O₄/PVP]/[Tb（BA）₃phen/PAN]double anisotropic electrically conductive-green fluorescence,magnetism and green-fluorescence sandwich-structured composite film,{[<Eu（BA）₃phen/PMMA>//<PANI/PMMA>]⊥[<Eu（BA）₃phen/PMMA>//<PANI/PMMA>]}/[Fe₃O₄/PVP]/[Eu（BA）₃phen/PAN]double anisotropic electrically conductive-red fluorescence,magnetism and red-fluorescence sandwich-structured composite film,{[<Tb（BA）₃phen/PMMA>//<PANI/PMMA>]⊥[<Tb（BA）₃phen/PMMA>//<PANI/PMMA>]}/[Fe₃O₄/PVP]/[Eu（BA）₃phen/PAN]double anisotropic electrically conductive-green fluorescence,magnetism and red-fluorescence sandwich-structured composite film,{[<Eu（BA）₃phen/PMMA>//<PANI/PMMA>]⊥[<Eu（BA）₃phen/PMMA>//<PANI/PMMA>]}/[Fe₃O₄/PVP]/[Tb（BA）₃phen/PAN]double anisotropic electrically conductive-red fluorescence,magnetism and green-fluorescence sandwich-structured composite film.Further,tri-walled tubes were prepared on the basis of the fourth sandwich-structured composite film.The specimens were systematically characterized by a series of characterisation methods.The results show that the sandwich-structured composite film has excellent double anisotropic conductance and the conductance of the conductive direction is about 10⁸ higher than that of the insulating direction.In addition,by modulating the content of rare earth complexes,polyaniline and Fe3O4 nanoparticles,the double anisotropic conductance,magnetism and fluorescence of the sandwich-structured composite film can be adjusted.The performances of the tri-walled tubes are consistent with those of the sandwich-structured composite film.The combination of special Janus nanoribbon with sandwich structure achieves microscopic and macroscopic partitions in 2D films,reducing the harmful interactions among various materials.The novel sandwich-structured composite film will have potential applications in the fields of electronics industry,gas sensing and biomedicine.In addition,this design concept and preparation technology can be extended to construct other novel multi-functional materials.