Materials Science and Engineering
http://repository.aust.edu.ng/xmlui/handle/123456789/403
This collection contains Masters thesis of the Materials Science and Engineering Students from 2009-20222024-03-28T10:14:19ZMechanical Performance of PVA/PAN Complexed with Aluminium Oxide (Al2O3) Nanopaticles for Solid Polymer Electrolyte
http://repository.aust.edu.ng/xmlui/handle/123456789/5131
Mechanical Performance of PVA/PAN Complexed with Aluminium Oxide (Al2O3) Nanopaticles for Solid Polymer Electrolyte
Daudu, Suleiman Danjuma
Interest in solid polymer blends has increased due to the demand for flexible, lightweight, and long-lasting energy devices. Traditional lithium-ion batteries contain liquid electrolytes that pose a serious safety risk since they are chemically unstable due to the presence of carbonates, which are highly volatile and combustible. Thus, there is a need for the creation of solid-state electrolytes with reliable mechanical properties and a focus on safety and the environment. In this project, a polymer matrix of polyvinyl alcohol/polyacrylonitrile and aluminum oxide nanoparticles is combined together. To examine the solid polymer blend, A Fourier transform infrared resonance is used to characterize the produced films. Tensile testing and nanoindentation methods were used to measure the mechanical properties of the flexible films. polyvinyl alcohol/polyacrylonitrile based matrix with 7wt.% Al2O3 nano particle displayed the best tensile properties having a tensile strength, young’s modulus, Ductility and a toughness of 1.062 MPa, 1.01 MPa, 288.4% and 23.5 KJ/m3 respectively. However, the polymer based matrix with 10 wt% Al2O3 shows the highest value of Hardness and reduced modulus of 214.71 MPa and 6.19 GPa respectively as compared to the other compositions that was investigated.
Main Thesis
2022-11-10T00:00:00ZEffect of Partial Replacement of Cement with Metakaolin on the Physio-Mechanical Properties of Excavated Soil Reinforced with Natural Borassus Fruit Fibre.
http://repository.aust.edu.ng/xmlui/handle/123456789/5130
Effect of Partial Replacement of Cement with Metakaolin on the Physio-Mechanical Properties of Excavated Soil Reinforced with Natural Borassus Fruit Fibre.
Olanipekun, Khadijat Adeola
Large amounts of excavated soil, both clean and polluted, are frequently produced during construction projects which are typically disposed of in landfills. This research explored a method to re-use the excavated soil as a construction material through partial replacement of cement with metakaolin and reinforcing with 0.2% Natural Borassus fruit fibre. The tests conducted were Moisture content, Particle size distribution, Material density, Atterberg Limit test, Linear shrinkage, Compressive strength test, Water absorption and FTIR while observing several material characterization methods such as; SEM, XRD, XRF from previous research. The average compressive strength results obtained after 28 days curing at room temperature for Mortar cubes with fibres and Mortar cubes with no fibre reinforcement were 7.5 MPa and 7.6 MPa respectively. Their failure pattern was satisfactory, there was about 6% increase in the water absorption from its 7th day result to its 28 days. The functional group did not show any significant change over the curing period and fibre content as observed with the FTIR. This shows a possibility in the usage of the constituents’ materials for sustainable construction.
Main Thesis
2023-06-07T00:00:00ZSurface Morphology and Mechanical Characterization of MoO3/PEDOT:PSS Blend Thin Films For Organic Solar Cells and Light Emitting Diode Applications
http://repository.aust.edu.ng/xmlui/handle/123456789/5129
Surface Morphology and Mechanical Characterization of MoO3/PEDOT:PSS Blend Thin Films For Organic Solar Cells and Light Emitting Diode Applications
Kum, Tatchen Buh
Access to cheap and reliable electricity is a requirement for improved quality of life and industrialization. Solar energy harvesting for electricity generation has been a promising area where solar cells are combined into modules and then panels are used to harvest solar energy for electricity. However, the initial acquisition cost of active solar is still a major barrier. There is therefore a dire need for efficient and affordable solar technologies to help mitigate the current global energy crisis. Organic and perovskite photovoltaics pose superior properties and cheaper costs. Degradation, stability, and durability are the current issues faced with organic and perovskite solar cells stopping them from being commercialized or used in a large scale. It is important to carefully study the different thin films layers making up these devices to investigate these issues of stability, degradation and durability. Over the years, both experimental and computational techniques have been used to study these issues. The mechanical properties of these thin film devices are very crucial for the development and implementation of mechanical durable devices.In this work, nanoindentation is mainly employed to investigate the effects of annealing temperatures and MoO3 blended ratios on the surface morphology, sheet resistance, mechanical properties as well as microstructure of PEDOT:PSS/MoO3 thin film blends as hole transport materials (HTM) for photovoltaics and OLED applications. Results from this study suggest that, the introduction of different percentages of the transition metal oxide (MoO3 ) into PEDOT:PSS significantly modifies the surface morphology, microstructure and mechanical properties in the different temperature regimes. (60 0C, 80 0C, 100 0C, 120 0C). Furthermore, PEDOT:PSS/MoO3thin film blends with small blended ratios of MoO3 (1:0.1 and 1:0.3) generally exhibit low sheet resistances, better surface morphologies and a good balance in mechanical properties (elastic vi modulus and hardness). A balance of properties as in hybrid thin films with low blended ratios is required to develop efficient and mechanical durable electronic devices. Finally, it was also found that, high blended ratios of MoO3 leads to high surface roughness and high sheet resistance which are unfavorable for device performance.
Main Thesis
2022-09-07T00:00:00ZAssessment of Beneficiation Process of a Nigerian Barite Source for Utilization as Oil Drilling Mud
http://repository.aust.edu.ng/xmlui/handle/123456789/5089
Assessment of Beneficiation Process of a Nigerian Barite Source for Utilization as Oil Drilling Mud
Afolayan, David Oluwasegun
The texture and size distribution of various species of gangue minerals affect the beneficiation of barite and lower the specific gravity of barite as-mined. About 9% of the barite used in the oil industry in Nigeria is imported, even though it is found in abundance in eight states of the country. This study has examined barite from deposits in Torkula, Benue State of Nigeria for application as oil drilling mud. Physico-chemical and rheological tests were conducted, specific gravity measurements were taken along with moisture content, hardness, gel strength, viscosity and yield point. Mineral samples collected were found to have SG ranging between 3.98 and 4.42, a pH of 8.015, moisture content of about 0.161% and a Mohr’s hardness of between 3.5 and 5.0. Slight beneficiation processes are required to completely refine the barite mineral from all the gangue minerals, and to meet the API, DPR standards for oil drilling.
2017-12-12T00:00:00Z