Dissertation > Excellent graduate degree dissertation topics show

Solution-based Synthesis and Optical Properties Investigation of Rare-earth Doped Fluoride Upconversion Microcrystals/Nanocrystals

Author: XianJianBo
Tutor: SunJiaYue
School: Beijing Technology and Business University
Course: Applied Chemistry
Keywords: fluoride nanocrystals upconversion materials optical properties
CLC: TB383
Type: Master's thesis
Year: 2011
Downloads: 16
Quote: 0
Read: Download Dissertation

Abstract


Lanthanide-doped luminescent nanomaterials have great potentials in the fields ofthree-dimension displays, optical devices, biosensors and anti-counterfeiting applications.Particularly, the use of lanthanide-doped upconversion （UC） nanomaterials as biolabels forsensitive biological detection has attracted considerable interests due to their unique opticalproperties. Recently, fluorides have been used as an attractive host for phosphors withinteresting UC luminescent properties because of their high UC efficiency and excellentchemical stability. Establishing well-controlled synthetic strategies to these materials,understanding their growth and luminescent mechanisms, and the relationships of theirstructures, morphologies and optical behaviors, are crucial to the production ofnanomaterials with designated optical properties.Lanthanide-doped NaGdF4UC nanocrystals （NCs） with good crystallinity,contrallable morphologies and uniform size were prepared in water-ethanol-oleic acid-sodium oleate system via a facile wet chemistry strategy. Multicolor UC luminescenceswere achieved in NaGdF4NCs through control of different combinations of lanthanidedopants and dopant concentration, which are promising for the applications of multiplebiolabels. The results indicate that this work provides a new way for the preparation ofhigh quality fluoride NCs.A series of MF2:Yb3+/Er3+(Tm3+)（M=Ca, Sr, Ba） UC NCs were synthesized byhydrothermal method in water-ethanol-oleic acid-sodium oleate system. The effects ofexperimental conditions on the morphology and structure of MF2:Yb3+/Er3+NCs wereinvestigated, and the optical properties and characteristics of structure of the as-preparedsamples also have been measured. Using SrF2:Yb3+/Er3+as a model, the effect of differentsurfactants on the morphologies and optical behaviors of MF2:Yb3+/Er3+NCs wereinvestigated, and structural and kinetic factors governing the anisotropic growth tendencyand shape evolutions on nanoscale under hydrothermal environment are systematicallystudied.In modified water-ethanol-oleic acid system, BaYF5:Yb3+/Er3+UC NCs with tunablesizes were prepared by adjusting experiment conditions. The surface effect andsize-dependent UC luminescence behaviors have been observed in BaYF5:Yb3+/Er3+NCs.In addition, BaYF5:Yb3+/Er3+UC materials have been synthesized via a surfactant-freeaqueous solution rout. Different morphologies and structure can be controlled by varying the different fluorine sources, temperature and reaction time. More importantly, therelationships of their structures, morphologies and optical behaviors have been discussed.

Related Dissertations

  1. Modification and Application of the Waste Fluorgypsum and the Treating of High Concentrations Fluoride Wastewater,X703
  2. Optical Properties of Chlorphyll-a in Reservoir Water and Its Concentration Inversion Models by Remote Sensing,S127
  3. Fluorine silicone acrylate copolymer emulsion synthesis and properties of,TQ316.334
  4. The Mechanism of the Selenium Antagonistic Action on the Experimental Rats with Fluorosis,R114
  5. Improvement of the Method of Establishment Animal Dental Fluorosis Model Caused by Coal-burning and the Effect of Excessive Fluoride on the Expression of KLK4 and DPPI Protein in the Rat Ameloblast,R783
  6. Modification of Poly(Vinylidene Fluoride) Via Atom Transfer Radical Polymerization,TQ325.4
  7. First-principles study of the structure and optical properties of the high-pressure alkali metal (Li, Na, K),O521.2
  8. Synthesis, Conformation and Character of W/Cu/S Supermolecule Clusters Containing Tp~* Group,O611.4
  9. Construction, Characterization and Properties of Tp~*-Containing W/S/Cu Clusters,O611.4
  10. Surface Plasmons and Nonlinear Optical Properties in Bimetallic Core-shell Nanoparticles,TB383
  11. Preparation and Surface Functionalization of Mg-doped ZnO Quantum Dots,O614.241
  12. Treatment of High-concentration Fluoride Wastewater by Fluidized Bed Crystallization Method,X703
  13. Preparation and Characterization of PVDF Composite Hollow Fiber UF Membranes,TQ028.8
  14. Investigation of Electrochemical Reducation Process of K2 TiF6/TiO2 in Fluoride Molten Salt,O611.3
  15. Colorimetric Determination of CdS Nanocrystals Concentration,TB383.1
  16. Studies on Itraconzole Nanocrystal Dry Suspension,TQ463.53
  17. The Research of the Dye-Sensitized Nanocrystalline TiO2 Solar Cells,TM914.4
  18. Raman Investigation of Silicon Nanocrystals: Quantum Confinement and Laser-induced Thermal Effects,TB383.2
  19. Cu 2 ZnSnS x Se 4-x thin film solar cell absorber material Preparation and Characterization,TM914.4
  20. CdSeTeS quaternary alloy quantum dots microwave-assisted aqueous phase synthesis , optical properties , and biological applications,O614.242
  21. Wide spectrum monitor thin films by electron beam evaporation system development and application,O484.1

CLC: > Industrial Technology > General industrial technology > Materials science and engineering > Special structural materials
© 2012 www.DissertationTopic.Net  Mobile