Dissertation > Excellent graduate degree dissertation topics show

The Deposition of Continuous SiO2and Gold Shells on Tween-20Modified Fe3O4Superparticles

Author: JinXiuMei
Tutor: YangWenSheng
School: Jilin University
Course: Physical and chemical
Keywords: Shell Au SiO2 Aggregates Nanoparticles Coated Nuclear Magnetic Surface modification Iron oxide Core-shell structure Volatile solvent Silica Miniemulsions Solution Dispersion Particle size Prehydrolyzed Preparation Oleic Acid Absorption Spectroscopy
CLC: TB383
Type: Master's thesis
Year: 2013
Downloads: 42
Quote: 0
Read: Download Dissertation

Abstract


Superparamagnetic iron oxide nanoparticles have attracted considerable interests dueto their application potentials in biotechnology. But usually the naked iron oxidenanoparticles are readily to undergo aggregation and oxidization, which limit theirpractical applications. A general strategy to protect the iron oxide particles is todeposit inert shells on their surface. SiO2and Au are considered to be the idealcoating layers due to their excellent chemical stability and biocompatibility. Both ofFe3O4/SiO2and Fe3O4/Au have very important applications in biotechnology. So theobjective of researching is to prepare the composite particles with good dispersibility,controlled particles′sizes and magnetic content, and good response ability.In the second chapter, Tween-20-modified Fe3O4superparticles were obtained by theemulsion droplet solvent evaporation method. And then analysis the effects of theconcentration of Fe3O4nanoparticles in oil phase and the volume ratio of oil phaseagainst water phase on the size of Fe3O4superparticles. At last the superparticleswere directly transferred into a pre-hydrolyzed St ber system to carry out silicacoating. The Size and the thickness of silica coating layer of Fe3O4/SiO2particleswere tunable. Then, we developed a facile approach to deposit continuous Au shell on Fe3O4colloidal superparticles （SPs）. In this new approach, first the Fe3O4nanoparticlessynthesized by the typical Massart’s method were modified with oleic acid, and thenTween-20-modified Fe3O4SPs were obtained by the emulsion droplet solventevaporation method. After the addition of HAuCl4and30min incubation, reductionof Au3+by ascorbic acid resulted in the deposition of continuous Au shell on theFe3O4SPs. The as-prepared Fe3O4/Au core-shell particles showed good chemicalstability and efficient photo-thermal conversion performance under the irradiation ofnear infrared laser. The thickness of Au shell and the absorbance peak were tunableby changing the changing the concentration of HAuCl4in the growth solution. Theobtained Fe3O4/Au core-shell particles have a lot of advantages, such as excellentchemical stability, superparamagnetic properties and efficient photothermalconversion performance under laser irradiation at808nm, and were expected to be auseful material for biodetection and cancer therapy. This approach could also beextended for the deposition of continuous Ag shells on the Tween-20modified Fe3O4SPs. The resulting Fe3O4/Ag core–shell particles showed extensive absorbance in theNIR region attributed to the plasmon peaks of the Ag shells.

Related Dissertations

  1. Tetra-tert- butyl- perylene polyhedral micro-nano crystal with XANES and XEOL research,TB383.1
  2. Synthesis and X-ray Absorption Spectroscopy Study of Nano Functional Materials,TB383
  3. Studies on the Interaction of Drugs and Nanoparticles Materials with Bovine Serum Albumin by Spectroscopy,O657.3
  4. Study on Long-Range Differential Optical Absorption Spectrometry for Atmosphere Monitoring,X831
  5. Theoretical Analysis and Experimental Study on Differential Optical Absorption Spectroscopy (DOAS) for Flue Gas Monitoring,X831
  6. Solid phase extraction - atomic spectral separation analysis applied research,O657.31
  7. On-Line Mercury Concentration Evaluation Method Using an Absorption Spectroscopic Technique,O433
  8. Study on the Binding of Small Molecules to DNA and DNA Bases as Well as the Effect of CdS Nanoparticles on the Binding Behavior,R91
  9. Study on Multi-Point Optical Fiber Methane Measurement System,TP274.5
  10. System Design and Experiment of Mid-infrared Methane Detection,TN215
  11. Study on the Interaction of Cucurbiturils and Quinoline、2,2’-dipyridine Derivatives,O641.3
  12. Study of the Interaction of Native DNA and Nucleotides with Compounds of Germanium,Q52
  13. A Study on Atmospheric Monitoring Based on Differential Optical Absorption Spectroscopy,O433.1
  14. Studies on the Methods of Determination of Functional Components in Grape Seeds,O657.3
  15. Spectrophotometry in pharmaceutical analysis - flavonoids , research analysis nicotinamide,TQ460.7
  16. Rare earth ions and micro- peroxidase -8 Mechanism of the Interaction,O641
  17. In Vitro Study on the Ion Release from Two Ni-Cr Dental Alloys,R783.1
  18. Research on Application of Differential Optical Absorption Spectroscopy for Atmospherr Environment Pollution Monitoring,TH744.1
  19. Ultrasound-assisted Extraction and Microwave-assisted Extraction for Flavones from Euonymus Alatus Sieb,TQ461
  20. Cucurbiturils induced room temperature phosphorescence of caffeine and its interaction studies with triphenylmethane compounds,O621.25

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