Magister Scientiae - MSc (Chemistry)

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https://hdl.handle.net/10566/14387

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Browsing by Author "Abbo, Hanna"

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    Coordination polymers as heterogeneous catalysts for oxidation reactions
    (University of the Western Cape, 2014) Alarbi, Zohra; Titinchi, Salam; Abbo, Hanna
    This study describes the synthesis and characterisation of coordination polymers complexes of Cu(II) and VO(IV) with two polymeric ligands N,Nʹ -1,2-phenylene bis(5-methylenesalicylidenamine)(L1) and N,Nʹ -1,4-butylene bis(5 methylenesalicylidenamine) (L2). Ligands L1 and L2 formed by condensation of 5,5ʹ-methylene bis-(salicylaldehyde) with 1,2-phenylenediamine and 1,4-diaminobutane respectively. The ligands and the complexes were characterized by UV/Vis spectroscopy, proton and carbon nuclear magnetic resonance spectroscopy (1H and 13C-NMR), Fourier transform infrared spectroscopy (FTIR), high resolution scanning electron microscopy (SEM) and thermogravimetric Analysis (TGA)
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    Graphene based materials for carbon capture
    (University of Western Cape, 2020) Kelly, Gabrielle Enid; Titinchi, Salam; Abbo, Hanna
    The adverse effects of CO2 and greenhouse gas emissions into the atmosphere is believed to be one of the causes of climate change. The seriousness of global warming is encouraging the development of technologies designed to reduce CO2 emissions. Adsorption in the broadest context can be considered to be a promising method to address this due to the energy saving potential and regenerability, compared to other techniques. In this study, graphite was first oxidized to graphene oxide (GO) with concentrated acid. This was followed by formation of the aminosilanes viz. 3- aminopropyl-triethoxysilane (APTES), tris(2-aminoethyl)amine (TRIS) and guanidine being functionalized onto the surface of graphene oxide (GO). A second series involving the ordered mesoporous materials (OMS) was prepared employing cetyltrimethylammonium bromide (CTAB) and P123 triblock copolymer, as the structure directing agents for the organization of polymerizing silica species. Following the self-assembly of OMS onto GO, the so formed GO-OMS compound was modified with polyethylenimine (PEI). Several characterization techniques such as X-ray powder diffraction (XRD), Fourier Transform Infra-Red (FT-IR) spectroscopy, high resolution scanning microscopy (HRSEM), high resolution transmission electron microscopy (HRTEM) and N2 physisoprion employing the Brunauer-Emmett-Teller (BET) analysis to determine specific surface areas of porous solid materials were employed to study the structural, morphological and textural properties of the adsorbents.
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    Photocatalytic degradation of organic pollutants using Ag-Fe₃O₄/SiO₂/TiO₂ nanocomposite
    (University of the Western Cape, 2015) Noganta, Siyasanga; Titinchi, Salam; Abbo, Hanna
    The global lack of clean water for human sanitation and other purposes has become an emerging dilemma for human beings. The presence of organic pollutants in wastewater produced by textile industries, leather manufacturing and chemical industries is an alarming matter for a safe environment and human health. For the last decades, conventional methods have been applied for the purification of water but due to industrialization these methods fall short. Advanced oxidation processes and their reliable application in degradation of many contaminants have been reported as a potential method to reduce and/or alleviate this problem. Lately, it has been assumed that incorporation of some metal nanoparticles such as magnetite nanoparticles as photocatalyst for Fenton reaction could improve the degradation efficiency of contaminants. Core/shell nanoparticles, are extensively studied because of their wide applications in the biomedical, drug delivery, electronics fields and water treatment. The current study is centred on the synthesis of silver-doped Fe₃O₄/SiO₂/TiO₂ photocatalyst. Magnetically separable Fe₃O₄/SiO₂/TiO₂ composite with core–shell structure were synthesized by the deposition of uniform anatase TiO₂ NPs on Fe₃O₄/SiO₂ by using titanium butoxide (TBOT) as titanium source. Then, the silver is doped on TiO₂ layer by hydrothermal method. Integration of magnetic nanoparticles was suggested to avoid the post separation difficulties associated with the powder form of the TiO₂ catalyst, increase of the surface area and adsorption properties. Lastly and most importantly magnetic nanoparticles upsurge the production of hydroxyl groups or reduced charge recombination. The a synthesized catalysts were characterized using Transmission Electron Microscopy, X-ray Diffraction; Infra-red Spectroscopy, Scanning Electron Microscope and Energy Dispersive Spectroscopy. Other characterization techniques includeVibrating Sample Magnetometry, Brunauer Emmett Teller analysis and Thermogravimetric analysis. The average size of the particles size is 72 nm. Furthermore the photocatalytic performances of the magnetic catalysts were assessed in comparison with that commercial titanium dioxide for the degradation of methylene blue using photochemical reactor under ultra violet light. The results showed that the photocatalytic activity was enhanced using Fe₃O₄/SiO₂/TiO₂ and Ag-Fe₃O₄/SiO₂/TiO₂ compared with that for Fe₃O₄, commercial titanium dioxide powder.