Master Degree / Yüksek Lisans Tezleri

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Department: search.filters.department.Thesis (Master)--İzmir Institute of Technology, ChemistrySubject: search.filters.subject.Silica

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  • Master Thesis
    Synthesis and Characterization of Monodispere Silica Based Functional Nanoparticles for Multi-Purpose Applications
    (Izmir Institute of Technology, 2009) Altın, Burcu; Özçelik, Serdar; Özçelik, Serdar; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    The Stöber method was performed to tune the size of monodisperse silica nanoparticles in the range of 10 to 500 nm. It was observed that increasing amount of reactants favors the formation of larger particles A Stöber method in the presence of L-lysine as a catalyst instead of ammonia was developed to prepare well-ordered, highly monodisperse silica nanoparticles based on the hydrolysis and condensation of TEOS. The effect of medium temperature, amounts of L-lysine, TEOS, octane and dye on the size of particle was investigated. It was found that L-arginine increased the size of particles. The amount of TEOS was determined to be 50.0 mmol to obtain the smallest size of particle. The mole of L-lysine slightly altered the size of particles, however the surface of particles was substantially covered by L-lysine. The presence of octane does not change the size of particles. The amount of dye molecule Rhodamine B isothiocyanate (RBITC) does not alter the size of nanoparticles. We showed that temperature plays important role tuning the particle size from 5.0 nm to 80.0 nm.MTT assay indicates no cytotoxicity of the silica particles against MCF-7 (human breast cancer cell lines) and PC-3 (human prostate cancer cell lines) cancer cell lines. The particles enter to the cells within 5 minutes with a concentration of 0.1.g/mL. We propose that these particles can be used in the field of bioimaging and drug delivery.
  • Master Thesis
    Use of Amine-And Mercapto-Modified Silica as Soild Phase Extraction Sorbent for Speciation of Inorganic Selenium Prior To Determination by Atomic Spectrometric Techniques
    (İzmir Institute of Technology, 2010) Dönertaş, Esen; Eroğlu, Ahmet Emin; Eroğlu, Ahmet Emin; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    Silica-based sorbents containing amino-, mercapto-, and both functional groups (bifunctional) were prepared and used for the sorption of inorganic Se(IV) and Se(VI) species from waters prior to their determination by atomic spectrometric techniques, namely, inductively coupled plasma mass spectrometry (ICP-MS) and hydride generation atomic absorption spectrometry (HGAAS). The presence of the functional groups on the surface of the silica was demonstrated by using several characterization techniques such as scanning electron microscopy (SEM), solid-state NMR spectroscopy, thermo gravimetric analysis (TGA), elemental analysis and Brunauer-Emmett-Teller (BET) surface area analysis. Amine-modified silica was found to be selective towards Se(VI) at pHs 2.0 and 3.0 whereas mercapto-modified silica retains Se(IV) over a wide range from acidic regions to pH 4.0. Bifunctional silica, on the other hand, possesses the good features of the two sorbents; it can be used in the separate sorption of Se(IV) or of both Se(IV) and Se(VI) species. Acidic pHs (<1.0) are convenient for the sorption of Se(IV) alone where no sorption is observed for Se(VI). Alternatively, pH can be adjusted to 2.0 or 3.0 and Se(IV) and Se(VI) can be retained simultaneously. Desorption of selenium species from the sorbents was realized with two different eluents; 0.2% (m/v) KIO3 in 1 M HCl was used for Se(IV) and 2.0 M HCl for Se(VI). The efficiency of the proposed sorbents was demonstrated through spike recovery tests carried out with bottled drinking and tap water samples and the percentage recoveries were found to change between 82.2 ± 7.1 and 109.4 ± 3.6 for Se(IV). For Se(VI), mechanically mixed amino- and mercapto-modified (MIX) silicas in (1:1) ratio has shown the best performance with percentage recoveries of 87.1 ± 3.6 and 74.5 ± 6.6 for the spiked bottled drinking and tap water samples, respectively.