| Recently, photoluminescent-electrical-magnetic multifunctional nanomaterials have revealed their potential applications in the biomedical field and nano-electronics, etc. owing to their unique multifunctionality. Most of the existing photoluminescent-electrical-magnetic multifunctional nanomaterials are composite structures that are composed of directly mixed photoluminescent, electrical and magnetic materials. This kind of structure leads to the severe decrease of luminescence performance of the materials. In order to reduce the adverse impact of electrical and magnetic materials on the photoluminescent material, in this dissertation, several specially structured one-dimensional nanomaterials, including coaxial nanofibers, coaxial nanobelts and Janus nanobelts, etc., are designed and fabricated based on electrospinning technique. These specially structured one-dimensional nanomaterials can realize the isolation of electrical and magnetic materials from photoluminescent material, leading to the great enhancement of luminescence performance. Besides, two-dimensional structures and functions can be realized in these specially structured one-dimensional nanomaterials, such as achieving flexible parallel nanocables array and anisotropically conductive films with high anisotropy.1. Magnetic-photoluminescent bifunctional coaxial nanofibers consisted of Tb(BA)3phen/PVP as sheath and Fe3O4 nanoparticles(NPs)/PVP as the core are constructed via coaxial electrospinning, and their morphology, structure, magnetism and photoluminescent property have been studied. Results indicate that the impact of magnetic substances on photoluminescent substances does greatly reduce based on the structure of coaxial nanofibers, and one-dimensional nanomaterials with excellent down-conversion and magnetism are obtained. The mechanism of the enhanced photoluminescence is also proposed. In order to verify the universality of this technique, the coaxial nanofiber with strong up-conversion and magnetism is also fabricated, which is composed of NaYF4:Yb3+,Er3+ NPs/PVP as sheath and Fe3O4 NPs/PVP as core.2. New type of coaxial spinneret is designed and fabricated for the first time, which overcomes the technical problem that the traditional coaxial spinnerets are difficult to electrospin the solutions with high viscosity. The defects of traditional coaxial spinnerets are analyzed and the advantages of the new-typed coaxial spinneret are discussed. By using the new-typed coaxial spinneret, novel magnetic-photoluminescent bifunctional coaxial nanobelts consisted of Tb(BA)3phen/PMMA as sheath and Fe3O4 NPs/PMMA as the core, which possess excellent down-conversion and magnetism are constructed. The mechanism of the enhanced photoluminescence is also proposed. In order to verify the universality of this technique, the coaxial nanobelt with strong up-conversion and magnetism is also fabricated, which is composed of NaYF4:Yb3+,Er3+ NPs/PMMA as sheath and Fe3O4 NPs/PMMA as core.3. Parallel spinneret is designed and fabricated for the first time, and magnetic-photoluminescent bifunctional Janus nanobelts with novel structure are constructed by using the parallel spinneret. The Janus nanobelt is composed of Tb(BA)3phen/PMMA as one side and Fe3O4 NPs/PMMA as the other side, forming a asymmetric dual-sided structure, and this kind of structure can also help to effectively isolate the magnetic substances from photoluminescent substances to achieve strong down-conversion and magnetism. In a similar vein, the Janus nanobelt consisted of NaYF4:Yb3+,Er3+ NPs/PMMA as one side and Fe3O4 NPs/PMMA as the other side also shows superior up-conversion and magnetism.4. By using the new-typed coaxial spinneret and rotary drum collector, ribbon-shaped coaxial electrical conductive nanocables array that composed of Tb(BA)3phen/PMMA as sheath and Fe3O4 NPs/polyaniline(PANI)/PMMA as core is fabricated for the first time. Separated parallel conduction, magnetism and photoluminescence are simultaneously realized in this novel material. Meanwhile, we find that the new-typed coaxial spinneret also has a merit that it is feasible to conveniently tune the core proportion of product. Based on this, a series of ribbon-shaped coaxial electrical conductive nanocables arrays with different core proportions are prepared, and the influence of core proportion on electrical conduction, magnetism and photoluminescence is discussed.5. By using dual-parallel spinneret and rotary drum collector, Janus nanoribbons array that consisted of Tb(BA)3phen/PMMA as one side and Fe3O4 NPs/PANI/PMMA as the other side is synthesized. Owing to the unique nanostructure, the conductance along with the length direction of nanoribbons reaches up to eight orders of magnitude higher than that along with perpendicular direction, which is by far the most excellent conductive anisotropy for anisotropic conductive materials, and meanwhile, magnetism and photoluminescence are also integrated in the product.6. Triple-parallel spinneret is designed and manufactured for the first time. We use triple-parallel spinneret and rotary drum collector to fabricate novel tricolor flag-liked microribbons array, in which every microribbon consists of a PANI/PMMA as middle region, Tb(BA)3phen/PMMA as one side and Fe3O4 NPs/PMMA as the other side, just like tricolor flag. The tricolor flag-liked microribbons array possesses high conductive anisotropy, magnetism and photoluminescence as well, and the degree of anisotropy also reaches up to the mulriple of 108. |
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