Fabrication And Characterization Of TiO₂ Nanomaterials By Electrospinning

As a simple and quick method for preparation of nano- or submicrometer fibers, great progress has been made in electrospinning technique in the past decade. Therefore, electrospinning technique has become one of the current studied subjects in the nanomaterials research field. Electrospinning origins from that electrically charged fluid is forced jets in the high voltage electrostatic field. Electrospinning occurs when the electrical forces at the surface of a polymer solution or melt overcome the surface tension and cause an electrically charged jet to eject. When the jet is dried or solidified, an electrically charged fiber remains. This charged fiber can be directed or accelerated by electrical forces and then collected in mats or other useful geometrical forms. Nonwoven membranes composed of electrospun fibers have a large specific surface area and small pore size compared with commercial textiles, and have many potential applications in the fields of filters, nanocomposites, wound dressings and engineering scaffolds.In this dissertation, sol-gel method was applied to prepare the precursor solution with a viscosity, and electrospinning technique was used to fabricate PVP(K30)/Ti(SO₄)₂, PVP(K90)/Ti(SO₄)₂, PVP(K90)+PMMA/Ti(OC₄H₉)₄,PMMA/Al((CH₃)₂CHO)₃ composite nanoribbons. TiO₂ nanofibers with porous surface, TiO₂ nanofibers with flexibility, TiO₂ nanoribbons and Al₂O₃ nanoribbons were obtained by calcinations of the above relevant composite microfibers.The morphology of fibers were discussed by adjusting all the important parameters such as concentration of PVP(PMMA), voltage, distance between tip and collector, the mass of metal salts added to the sol. It was found that these factors were the main factors affecting the properties of the composites.The TiO₂ nanofibers with diameters of 100-200nm and a length of 200μm. The TiO₂, Al₂O₃ nanoribbons with a width of 8-15μm and a length of 200-300μm.The samples were characterized with XRD, TEM, SEM, TG-DTA and FTIR in detail. It was indicated that the as-prepared nanofibers and nanoribbons exhibited polycrystalline structure which were different from monocrystalline structures of the TiO₂ nanofibers and TiO₂, Al₂O₃ nanoribbons previously reported. The synthesis of the nanoribbon with this new microstructure might provide a novel route to the nanomaterials.