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Modified Zeolitic Nanostructures: Synthesis, Characterization and the Investigation of Their Catalytic-Sorption-Antibacterial Applications

Padervand, Mohsen | 2013

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  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 45644 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Gholami, Mohammad Reza; Gobal, Fereydoun
  7. Abstract:
  8. Modified zeolitic nanostructures were prepared by sol-gel, hydrothermal and coprecipitation methods. At first step, natural zeolite was used as a support for preparing the Ag/AgBr/TiO2 photocatalysts. Their photocatalytic properties were studied by degradation of pollutants and microorganism inactivation at the presence of different illumination source. These processes were mechanistically investigated and the results were explained. At second step, mordenite anocrystals, which synthesized by hydrothermal method, were used as an effective support to prepare the AgX/TiO2/MOR photocatalysts. Photocatalytic degradation of an azo dye performed over these nanocomposites and a mechanism suggested for the reaction.In the next section, XFe2O4 magnetic nanoparticles (where X is Mn, Fe, Co and Ni) were synthesized by coprecipitation and hydrothermal method at the presence of organic tempelate. The prepared samples were characterized with XRD, VSM, FTIR, TEM and BET analysis methods. A theoretical study was performed to determine the most stable structure and also magnetic properties. In this section, X2+ ions were placed in the different tetrahedral and octahedral sites of their spinel structure, finally, the stabilization energy and the magnetic properties were calculated. NiFe2O4 magnetic nanoparticles were selected as the best magnetic cores for later applications.NiFe2O4 nanoparticles were coated by a silica layer through the water-in-oil microomolosion method. The zeolitic mordenite nanoparticles were grown on the NiFe2O4/SiO2 cores by hydrothermal method and at the presence of organic tempelates. The XRD, BET and TEM analysis confirmed this statement. Afterwards, the surface of nanostructures was modified by organic or metallic species.Modified magnetic core-zeolitic shell nanostructures were used for removal of toxic heavy metal ions from waste water. The removal mechanism, sorption isotherms and sorption kinetic were investigated. Ultimately, the antibacterial activity of the noble metal (Ag and Au) modified zeolitic nanostructures was studied by inactivation of E.coli as a pathogenic microorganism. Antibacterial mechanism, the effect of nanocomposite dosage and reuse ability was studied. A theoretical study was also performed on the interaction of metallic ion_head of GPTS-GLU species on the surface and the results compared to the experimental outcomes
  9. Keywords:
  10. Zeolite ; Environmental Pollutant ; Photosensitive Material ; Microorganisms ; Catalyst ; Magnetic Nanodot ; Photocatalytic Activity ; Adsorption Kinetics ; Antibacterial Activity

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