Study On Preparation And Properties Of Functional Fibers By Electrospinning

The optimal proportion was obtained by adjusting the composition and conditions of spinning solution. Semiconductor/polymer composite nanofibers with good fluorescence properties were successfully prepared by spinning the poly?vinyl pyrrolidone??PVP?/ethanol solutions. In addition, oxide nanofibers with various morphologies were also fabricated by spinning the PVP/N,N-dimethylformamide?DMF? solutions. Furthermore, their formation mechanism of hollow structure and properties of catalysis and gas sensing were systematically investigated. The contents of this paper are as follows:1. Quantum dots?Q Ds?/PVP nanofibers were prepared and their fluorescence properties were investigated. The composite nanofibers were fabricated by adding CdSe and Cd Te QDs solutions with different concentration to PVP/ethanol solution with a mass fraction of 8%. And on this basis, the effect of concentration and ligand on the properties of the nanofibers embedded with QDs were explored through the bright and dark field fluorescence microscopy images.2. 1D CeO₂ nanostructures, including uniform nanobelts and nanotubes have been successfully prepared via an electrospinning method and subsequent two-step calcination route by adjusting heating rates. And their possible formation mechanism was proposed. Au nanoparticles were deposited on CeO₂ nanotubes through a direct wet-chemical reaction or adding Au precursors during preparation of spinning solution, and their CO catalytic oxidation properties were analyzed. The results showed that the two-step calcination route had a benefit for CeO₂ fibers to form hollow structure and the nanostructures composite with Au could obviously improve their catalytic properties.3. By controlling the molar ratio of the components and the calcination process, SnO₂ and SnO₂/CeO₂ nanostructures, including solid fibers, belts and tubes, were obtained. And their formation mechanism of nanostructures with various morphologies was proposed. Their gas sensing properties were investigated, suggesting their high sensitivity and excellent selectivity for ethanol. In addition, CO catalytic o xidation properties of the samples were also obtained.4. SiO₂/SnO₂ core-shell nanofibers were prepared by spinning the mixed solution of tetraethylorthosilicate?TEOS? and SnC l2?2H2O via a single-spinneret electrospinning method. After calcining, the resulting fiber sample had an amorphous SiO₂ core and a shell consisted of SnO₂ particles. The fibers with various morphologies were obtained through adjusting the molar ratio of Sn and Si and the possible formation mechanism of core-shell nanofibers was proposed. The amount of SnO₂ precursors directly determined the compactness of the shell, resulting in the different gas sensing properties.5. Co₃O₄ and Co₃O₄/CeO₂ 1D structures were obtained by electrospinning method and their properties for CO catalytic oxidation were studied. As the content of Co?NO3?2 increased in the spinning solution, the resultant fibers changed from single-particle chains to multi-particle chains. The morphologies of prepared Co₃O₄/CeO₂ fibers included solid and belt- like structures. The results suggested that composite fibers had a higher performance for CO catalysis compared with single component.