【作者】 车立光；

【导师】 黄宗浩；

【作者基本信息】 东北师范大学 ， 高分子化学与物理， 2010， 硕士

【摘要】 稀土发光材料,特别是以氟化物作为基质的纳米材料具有优良的上转换发光特性,在新光源、生物传感器、化学传感器、红外量子计数器等等领域有广泛的应用前景,已成为高科技领域中的研究热点。本文以静电纺丝法成功制备了具有高上转换特性的复合纳米纤维,分别是PVP(聚乙烯吡咯烷烔）/ LaF3:Er3+复合纳米纤维和PPV(聚对苯乙炔)/ LaF3:Er3+,Yb3+复合纳米纤维。在纳米纤维的制备上,采用了共混纺丝的方法,即把制备好的纳米粒子混入最佳电纺浓度的聚合物溶液中,在常温下慢速率(每分钟50转左右)搅拌48h以上,充分混合均匀后静电纺丝。本文借助于现代化的测试手段,如利用透射电子显微镜(TEM)、扫描电子显微镜(SEM)对聚合物/LaF3:Ln3+复合纳米纤维材料的形态做了分析;利用红外光谱(FT-IR)和X射线粉末衍射仪(XRD)等对聚合物/LaF3:Ln3+复合纳米纤维材料的成分、材料内部原子或分子的结构或形态进行了表征;测试了聚合物/LaF3:Ln3+复合纳米纤维材料的上转换发光(UC)性质并进行了分析讨论。测试分析结果表明,复合纳米纤维的直径在200-400nm,LaF3:Ln3+纳米粒子的大小为40 nm左右,而且纳米粒子均匀分散在纳米纤维的内部和表面。用激发功率5mw、激发波长980nm的激光激发聚合物/LaF3:Ln3+复合纳米纤维,得到了高上转换发光,它的上转换发光强度与同等条件下激发LaF3:Ln3+纳米粒子的上转换发光强度相比,明显的增强。该结果还未见有文献报道,论文正在撰写之中。更多还原

【Abstract】 Due to the great specific surface area, the surface energy and activity of nanoparticles increase.Therefore,the nanoparticles show many special chemical and physical (light, electricity, magnetism, heat, etc.) properties and a lot of scientists have been attracted by these characteristic. Because rare earth materials, especially their fluoride, have excellent luminescent properties and potential application in new photosource, bio-sensor, chemistry sensor, infrared quantum counter and so on, they have become a hot research field recently.In this paper, composite nanofibers with high upconversion properties were successfully prepared by electrospinning method, such as PVP (polyvinylpyrrolidone)/LaF3:Er3+ and PPV (poly p-phenylene vinylene)/LaF3:Er3+,Yb3+ composite nanofibers. The manufacture steps were to blend the nanoparticles in polymer solution, then the mixed solution was stirred (the speed was about 50rpm) for 48h, finally electrospinning.By using the transmission electron microscope (TEM) and the scanning electron microscope (SEM), we characterized the morphology of nanofibers and distribution of nanoparticle in polymer/LaF3:Ln3+ composite nanofibers. And by using fourier transform infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRD) etc., we characterized chemical and crystal structure of polymer/LaF3:Ln3+ composite nanofibers. The upconversion (UC) properties of the polymer/LaF3:Ln3+ composite nanofibers were characterized and discussed.The results showed that the average diameter of composite nanofibers was 200-400nm and the average diameter of LaF3:Ln3+ nanoparticles was about 40 nm. The nanoparticles were uniformly dispersed in the composite nanofibers. Under the excitation of a 980 nm laser, the polymer/LaF3:Ln3+ composite nanofibers had emitted a high upconversion luminescence, and the upconversion luminescence intensity was stronger than that of LaF3:Ln3+ nanoparticles. Up to now, we have not seen the report about the above results, and the paper is being written now.更多还原