Dissertation > Excellent graduate degree dissertation topics show

Preparation of Core-shell Magnetic Nano-composite and Research Their Antibacterial and Catalytic Properties

Author: XiaHaiQing
Tutor: GuoHuiLin
School: Northwestern University
Course: Materials Physics and Chemistry
Keywords: Magnetic composite nanoparticles Antibacterial activity Composite antibacterial agents Photocatalytic Core-shell structure
CLC: TB383.1
Type: Master's thesis
Year: 2011
Downloads: 80
Quote: 0
Read: Download Dissertation

Abstract


Raising the level of production technology, to bring the improvement of living standards, along with also bring negative effects for human beings. Human increasingly serious pollution of the environment, and ultimately makes the increase in the types of bacteria growth and reproduction speed, increase the resistance of bacteria to antibiotics. This makes the novel antibacterial agents of the antibacterial ability appears to become very necessary. The most efficient nano-antibacterial agent, but its recovery and management inconvenience. This article to magnetic particles as the carrier, to be modified with the load on the surface of the magnetic core, antimicrobial agent, to prepare a magnetic composite antibacterial agent. This will not only ensure that the antibacterial agent is do nanoscale antimicrobial efficiency is high, while the recovery and management also becomes very easy. And by X-ray diffraction analyzer (XRD), X-ray photoelectron spectrometer (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fu li transform infrared spectroscopy the meter (FTIR), X-ray energy scattering were characterized by means of the resulting sample structure, morphology, magnetic detector (EDX) and superconducting quantum interference magnetic measurements (SQUID). Final study composite antibacterial agent in the antibacterial effect of different conditions. The paper work from the following three aspects. Combined solvothermal, hydrothermal and chemical reduction prepared Fe3O4 @ C @ Ag (?) Fe3O4 @ Ag magnetic composite nanoparticles. Fe3O4 @ C @ Ag composite particles have an average size around 250nm, with a strong magnetic properties, and its surface is deposited a layer of compact nano-silver particles, the average size of approximately 15nm. Instead, Fe304 @ Ag composite particles deposited on the surface of silver nanoparticles loose and the size segments. The antibacterial test conclusion: in the same system nano silver concentration of Fe3O4 _AT_ C Ag composite particles of antimicrobial activity than the Fe304 @ Ag. Antibacterial properties of the composite particles is related to the concentration and size of the nano-silver When the nano silver concentration 5μg/mL, Fe3O4 _AT_ the C _AT_ Ag strongest antimicrobial activity. This Ag-magnetic composite particles recyclable residual nano silver, but also the local concentration of nano silver increases to improve the efficiency of its antibacterial. Yin Nami silver having optical and catalytic properties, so Fe3O4 @ C @ Ag composite particles will be a widely used in many fields. Solvothermal synthesis of magnetic γ-Fe2O3 carrier. The study found that the reaction temperature and the concentration of the alkali source affect the phase composition, 160 ℃ can be obtained pure gamma-Fe2O3. 20,40 and 60 mmol / mL, followed by adjusting the concentration of the precursor FeCl3, can control the particle size of the product of the order of 205,280 and 403nm. The magnetic testing results show that the obtained γ-Fe203 is ferromagnetic, the saturation magnetization of 77.3 emu / g. So that the the composite particles operability stronger as the carrier prepared to γ-Fe203. By combining Solvothermal Stober and sol - gel hydrothermal method Preparation of magnetic composite nano-particles of γ-Fe2O3 _AT_ SiO2 _AT_ TiO2-Ag photodegradation experiments conclusion: methylene orange concentration of 30μg/mL, TiO2-Ag concentration of 1 mg / mL composite catalyst, photodegradation 1 h in 250W UV lamp methylene orange can be completely degraded. Due to the presence of a magnetic core so that this composite catalyst can be recycled efficiently reused, after 18 cycles of use, its catalytic activity is almost stable. Due to the presence of silver, γ-Fe2O3 @ SiO2 @ TiO2-Ag is not only in the dark conditions have a strong antibacterial, almost all the growth of bacteria can be suppressed under the conditions of UV irradiation. Not only has the ability but also has the ability to inhibit the growth of bacteria γ-Fe2O3 @ SiO2 @ TiO2-Ag composite particles in water treatment will have broad application prospects photocatalytic degradation of organic pollutants.

Related Dissertations

  1. Hydrothermal Synthesis of Oxide Hollow Spheres,TB383.4
  2. Study on the Syntheses and Antibacterial Acticity of Metal Organic Complexes Built from Three Carboxylate Ligands,O621.13
  3. Studies on Synthesis, Characterization and Properties of Fe-V Co-doped TiO2 Catalyst,O614.411
  4. Study on Phylogenetic Diversity and Bioactivity of Symbiotic Fungi of Coral,R284
  5. Investigation of Fabrication, Characterization and Property of Fuctional Titanium Dioxide Nanoporous Materials,TB383.1
  6. Prokaryotic Expression and Purification of Human Beta-Defensin-9,Q78
  7. Preparation and Photocatalytic Properties of Semiconductor Oxides,O643.36
  8. Copper oxide porous hollow microspheres Preparation and Characterization,O614.121
  9. More than enough calcium and magnesium metal ligand complexes Synthesis, Structural Characterization and Antibacterial Activity,O641.4
  10. Nano LaFeO 3 Controllable Synthesis and TiO 2 bridged construct composite photocatalyst,O643.36
  11. Preparation and Research of New Type Visible-light Active Photocatalyst BIVO4,O643.36
  12. Preparation and Properties of Platinum-based Catalysts for Potential Use in PEMFCs,TM911.4
  13. TiO 2 nanotube synthesis and modification and photocatalytic properties of,O643.32
  14. Nitrogen-doped SO 4 2 - / TiO 2 photocatalyst precipitation step Preparation and Photocatalytic Performance,O643.36
  15. Absorbent sheet synthesis and modification of,TB34
  16. Based on high-sensitivity Raman scattering enhancement Au-SiO 2 Multilayer nanostructure analysis and preparation of liquid substrates,TB383.1
  17. Feather Arctium chemical composition and biological activity of a preliminary study,R284.2
  18. Study on the Controllable Preparation and the Photocatalytic Properties of Nano-TiO2,X13
  19. Study on the Preparation and Performance of Titanium Dioxide Film,TB383.2
  20. Preparation and Photocatalytic Property of SnO2 Nanocomposite,TB383.1
  21. Compound Modification and Photochemical Catalysis Property of Nano-TiO2,TB383.1

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