Dissertation > Excellent graduate degree dissertation topics show

Nitrogen-containing mesoporous polymers and rare earth fluorides upconversion materials synthesis

Author: YangJianPing
Tutor: TuBo；ZhaoDongYuan
School: Fudan University
Course: Inorganic Chemistry
Keywords: Mesoporous polymer Soft template Mesoporous silica Core-shell structure Nanocrystalline Hydrothermal Synthesis
CLC: TB383.1
Type: Master's thesis
Year: 2010
Downloads: 228
Quote: 0
Read: Download Dissertation

Abstract


In the past ten years, mesoporous and nano-materials have special properties, is expected in catalysis, energy, electrochemistry, biology, devices and other fields with breakthrough applications which receive widespread attention. Currently mesoporous materials development, including synthesis of new materials as well as modification and modification of mesoporous materials in catalysis, electrochemistry, water treatment and other applications, as well as industrial synthesis of mesoporous materials. And with special optical properties upconversion materials, due to the light, bio-imaging and optical devices such as optical field to build great applications are gradually attracted people's attention. This thesis mainly around mesoporous functionalized polymer materials as well as upconversion materials synthesis and modification and expand. Is divided into three parts: (1) the synthesis of nitrogen-containing mesoporous polymers; (2) mesoporous silica coated upconversion materials; (3) Hydrothermal Synthesis of carboxyl-functionalized upconversion luminescence materials and water-soluble. In the second chapter, a soluble, low molecular weight urea - phenol - formaldehyde resin as the organic precursor triblock surfactant F127 as a template by solvent evaporation induced self-assembly method for the synthesis of ordered nitrogen mesoporous polymer. This material has a highly ordered structure, high surface area (385-420m2 / g), a large diameter (3.1-3.6 nm), pore volume (0.25-0.44 cm3 / g) and a high nitrogen content (2.69- 2.94%). UPF/F127 by adjusting the ratio of the urea content and the UPF resin polymerization time, and the structure of the product can be controlled nitrogen content, the nitrogen under the same conditions mesoporous polymer materials, the resulting nitrogen-containing mesoporous a more hydrophilic polymer material properties, and thus has a higher adsorption capacity of the water molecules, the presence of nitrogen group also significantly increased heavy metal ions (iron ions) adsorption capacity. In the third chapter, we use the amphiphilic surfactant Triton X-100-modified hydrophobic surface hydrophilic β-NaYF4 then Stober sol-gel method using β-NaYF4 coated in a thin layer on the silicon oxide, then using the surfactant · CTAB as a template coated with the sol-gel method mesoporous silica obtained β-NaYF4 @ SiO2 @ mSiO2 core-shell structure. Mesoporous silicon oxide layer has a uniform pore size (~ 2.3 nm), the pores open and adjustable shell thickness (from 50-90 nm). Mesoporous silica encapsulated β-NaYF4: Yb, Er nanorod core-shell structure still has significant upconversion luminescence properties. By wrapping mesoporous silica material in the up-conversion core-shell structure formed on the surface, not only changed the hydrophobic material is also better to keep the material upconversion luminescence properties, and mesoporous silicon oxide layer not only has good biocompatibility , easy modification of functional groups grafted and biological macromolecules, and the open pore channels for a variety of functionalized nanoparticles and biomolecules provides a place. When Rhodamine B dye molecules are adsorbed on mesopores, laser excitation at 980 nm, due to the conversion process, nanorods emit green light, green light is absorbed Rhodamine B dye molecules excite fluorescence again to achieve a secondary excitation. The striking feature in multicolor fluorescence has great application prospects. In the fourth chapter, we propose a simple one-step hydrothermal synthesis of various morphologies of water-soluble and carboxyl-functionalized NaYF4: Yb / Er. Upconversion materials. Dicarboxylic acids with small molecules, such as malonic acid, oxalic acid, succinic acid and tartaric acid as a chelating agent, by adjusting the reaction temperature, reaction time, dicarboxylic acid and sodium hydroxide, and the molar ratio of dicarboxylic acid type, including the cubic phase can be obtained α-NaYF4 and hexagonal β-NaYF4 materials, including spherical particles obtained, hollow tube, rod, sheet, coils, six Azusa, hexagonal polyhedral and hexagonal flake-shaped body and other appearance. In addition, we also investigated different morphologies NaYF4: Yb / Er material surface properties and upconversion luminescence properties. The results showed that the synthesized NaYF4: Yb / Er surface functionalized with a carboxylic acid group and has good water-dispersible, but also has a strong upconversion luminescence properties.

Related Dissertations

  1. Hydrothermal Synthesis of Oxide Hollow Spheres,TB383.4
  2. Multi-walled Carbon Nanotubes Au _AT_ of Pt, Au _AT_ of Pd core-shell structure of the catalyst preparation and electrochemical properties of,O643.36
  3. Flexible,rigid,Synthesis and characterization of mixed ligand complexes,O621.1
  4. Syntheses, Structures and Properties of Coordination Polymers with Aromatic Dicarboxylates,O631.1
  5. Syntheses, Structures and Properties of Metal-organic Coordination Polymers Based on Long-Chain Aromaticmulticarboxylate,O631.3
  6. Synthesis and Characterization of Polyaniline Micro/nano Structure and Its Composites,TB383.1
  7. Electroless Ni-Pon the Bulk Nanocrystalline Ingot Iron,TQ153.1
  8. Design, Preparation and Perfermance Study of Controlled Release Systems Based on Mesoporous Silica Nanoparticles(MSNs) and one Sensor for Lithium Ions,TP212
  9. Preparation and Properties of Platinum-based Catalysts for Potential Use in PEMFCs,TM911.4
  10. Preparation and Characterization of Doped BiFeO3 Nanocrystals,TB383.1
  11. Based on the two-dimensional graphene composites and preliminary application of,TB332
  12. Hydrogenated nanocrystalline silicon photovoltaic materials in hydrogen bonding defects in material structure and the impact of,TB383.1
  13. Novel core-shell structure of intelligent nano Synthesis and Characterization of Hydrogels,TB383.1
  14. Polyhedron iron micro and nano capsules Absorbing Materials Preparation and Properties,TB383.1
  15. Short pore Pd/Zr-Ce-SBA-15 Catalyst and Its Catalytic Performance VOCs,X511
  16. Porous electrode material of vanadium pentoxide Synthesis, Characterization and Properties,O614.511
  17. Study on the Preparation of Potassium Ion Sieve Membrane of High SiO2/Al2O3 and Its Application Performance,P746.2
  18. Syntheticism of Hydroxyl Acrylic Ester Emulsion Containing Phosphate Ester and Preparation of Water-dispersible Polyisocyanate,TQ630.4
  19. Selective Oxidation of Propane to Acrylic Acid over Mo-V-Sb-O Catalysts,TQ225.131
  20. Studies on the Hydrothermal Synthesis and Self-Assembly Principle of Dicarboxylic Acid Coordination Polymers,O631.1
  21. Modification and Photoelectrochemical Research Based on Nanocrystalline TiO2 Photoanode,TM914.4

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