Magister Scientiae - MSc (Nanoscience)
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Item type: Item , Antimycobacterial effects of cerium oxide nanoparticles on mycobacterium smegmatis(Univesity of the Western Cape, 2025) Mhlaba, Ezintle; Dube, AdmireBackground: Tuberculosis (TB) remains a global health crisis, with drug resistance posing a significant challenge. Albeit preventable and curable, TB still has a high mortality rate and has resurged as the leading cause of death from a single infectious agent surpassing COVID-19, above HIV/AIDS globally. The treatment of TB is a 6-month course which has low patient compliance due to the lengthy treatment duration and adverse effects, which ultimately leads to drug resistance – a health crisis! Drug resistance can be treated by different treatment options from the normal TB treatment which can be expensive. Nanotechnology holds promise to address these issues and circumvent drug resistance while offering cost-effective treatment options. Aims: Owing to their unique antibacterial mechanism, NPs have gained popularity in the biomedical field. This study aims to explore the antibacterial activity of cerium oxide nanoparticles (CeO2 NPs) as an innovative antimycobacterial agent, using Mycobacterium smegmatis as the mycobacterial research model. To the best of our knowledge, no studies in the literature report the activity of these NPs against mycobacteria. Hypothesis: This research hypothesized that CeO2 NPs can inhibit the growth of M. smegmatis.Item type: Item , Nanomaterial assisted maldi-tof ms-based antifugal susceptibility testing for Candida species(Univesity of the Western Cape, 2024) Young, Z’nita Lori’an; Africa, Charlene Wilma JoyceCandida spp. infections have increased due to invasive procedures, widespread antimicrobial use and higher rates of immunocompromised statuses. These infections often lead to therapeutic failure, due to rising antifungal resistance. MALDI-TOF MS has been used to detect resistant Candida strains. However, its sensitivity and selectivity can be compromised by background interference from conventional organic matrices. In this study, nanoparticles (NPs) have been proposed as a promising alternative, offering reduced interference, enhanced sample clean-up and enrichment for complex analyses. This study aimed to evaluate the suitability of nanomaterials as potential matrices for MALDI-TOF MS-based antifungal resistance profiling of Candida spp. The syntheses of silver NP (AgNPs) and gold NP (AuNPs) were conducted using roasted Coffea arabica seeds (CAS) extract and characterized using ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD) and high-resolution electron microscopy (HRTEM). UV-Vis spectroscopy of AgNPs and AuNPs showed absorbance peaks at 410 nm and 520 nm respectively, due to surface plasmon resonance. Identification of Candida spp. was performed using chromogenic agar and Sabourauds Dextrose Agar. Candida spp. antifungal susceptibility testing was conducted using the TREK Sensititre YO10 drug panel. While some improvements were observed when combining traditional matrices like α-cyano-4-hydroxycinnamic acid (HCCA) with AuNPs and AgNP, overall analytical performance did not show significant enhancements compared to conventional organic matrices. Although the NPs demonstrated some promise, the results were limited by poor interactions with Candida spp., unfavourable surface properties, and the species' inherent resistance mechanisms, which restricted ionization efficiency and resulted in poor reproducibility. Enhancements observed when NPs were applied in combination with a traditional HCCA matrix, were insufficient to warrant a shift from conventional methods. This emphasizes the need for further refinement of NP-based matrices to enhance their applicability in antifungal resistance analysis.Item type: Item , Olefin oligomerization over nanostructured ZSM-5(University of the Western Cape, 2025) Mazamelela, YolisaZSM-5 type zeolites are widely used as catalysts in oligomerization reactions due to its unique pore structure and high acidity, which enables it to selectively convert light alkenes (C2-C6) into larger oligomers in the gasoline, jet fuel and diesel hydrocarbon range. In oligomerization processes such as PetroSA’s Conversion of olefins to Distillate (COD) typical feeds consist of propylene and C5 to C6 olefins. Recently, there has been much interest in converting low-value naphtha streams, such as Light Cracked Naphtha (LCN) rich in C5 to C6 olefins, to high-value transportation fuels. Furthermore, the growing demand for longer-chain jet and diesel fuels requires that the properties of ZSM-5 be optimized to meet these demands. However, conventional microporous ZSM-5 catalysts are subject to diffusion limitations and rapid deactivation, particularly when processing C₅-C₆ olefins, due to their small pore size and high acid strength, which often led to coke formation and pore blockage. To overcome these limitations, this study investigates the catalytic performance of nano-sized ZSM-5 zeolites synthesized via hydrothermal methods, focusing on the effect of synthesis parameters such as alkalinity, aging time, and choice of structure-directing agent on the resulting crystal size and morphology. The primary objective was to enhance mass transport and catalytic efficiency in the oligomerization of 1-hexene, a model C₆ olefin, by reducing crystallite size and promoting external surface accessibility. The structural and physicochemical properties of the synthesized materials were extensively characterized using techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) surface area analysis, thermogravimetric analysis (TGA), and X-ray fluorescence (XRF). XRD confirmed the formation of a pure MFI-type crystalline phase, while TEM revealed nano-sized crystals (~90 nm) with well-faceted cubic to rectangular morphology. BET analysis showed a high surface area of 371 m²/g for the nano ZSM-5 catalyst, with an external surface area of 194 m2/g greater than its micropore area of 177 m2/g, indicative of enhanced external surface exposure. NH3-TPD also revealed nano-ZSM05 to have more weak/medium acid sites compared to the commercial catalyst with higher strong acid site density.