Studies On Luminescent Nano-particles Of Tungstates Doped With Rare Earth Ions Applied To Label

In the field of biochemistry, the technique of labeling and detecting the biological molecule has always drawn much attention. As a new kind of tagging probe, nano-particles, owing to their many peculiar properties and their great high technology applied prospect, can settle the problems of present labels effectively.With the development of nano-materials, preparation technology has made a great progress. Hydrothermal synthesis is one of important methods, because of its advantages, such as high purity and good crystallization of product. Meanwhile, this method also has some disadvantages, so solvothermal synthesis method emerged as require. In this paper, a hydrothermal/solvothermal pathway has been applied to synthesize luminescent nano-particles doped with rare earth ions, and the effects of a series of preparation conditions on luminescence were discussed respectively. This thesis is divided into six chapters.In the first chapter, one brief introduction about the luminescent label and the long afterglow material was given, as well as the basis and signification of this thesis.In the second chapter, solvothermal synthesis of crystalline CaWO₄ nano-sized powder was discussed. The nanoparticles have perfect crystallization and grain size. Furthermore, nanoparticles with different diameters can be obtained by changing organic additives.In the third chapter, hydrothermal synthesis of CaWO₄:Eu afterglow was studied. Some optimized conditions were found out: sintering temperature at 800℃, sintering time for 2h, and the doped concentration of Eu 0.1mol%⁰.2mol%. The phosphor powder has well luminescence and small size, without grinding. These works make a solid foundation for further research.In the fourth chapter, the characteristics of CaWO₄:Eu nanoparticles, prepared by solvothermal synthesis method, were systematically discussed. A series of preparation condition with solvothermal method were studied, especially the diameter of particles. Polyethylene glycol 2000 (PEG-2000) was used as organic additive in the experiment.