Mechanical Engineering
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Mechanical Engineering
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Item EFFECTS OF OXIDIZED SUCROSE CROSS-LINKED CASSAVA STARCH FILM ON THE PHOTOVOLTAIC PROPERTIES OF PEROVSKITE SOLAR CELLS(The Nigerian Institution of Mechanical Engineers (A Division of Nigerian Society of Engineers), 2021-09) J. Y. Jiya; J. S. Enaburekhan; M. T. Jimoh; E. C. Egwim; I. A. JosephDespite rapid progress in the perovskite solar cell efficiency, there have been concerns about issues which could affect the measurement accuracy and/or practical applications of these devices, amongst which are stability, scaling up (large area devices), and possible environmental effects related to the use of lead-based active material. Based on the findings from previous studies, an optimized biodegradable oxidized sucrose cross-linked cassava starch film layer with zirconium oxide is introduced as a desiccant and buffer against damp heat and thermal recycling. This modified photovoltaic device is capable of resisting ingress of moisture at elevated temperatures, withstanding temperature cycling without delamination, and as such, enables efficient and stable operation. The layers in the PSC were modified by replacing the conventional metallic counter electrode with a low-cost carbon counter electrode. The PSC device with the control architecture underwent a more rapid degradation, particularly within the first 288 hours though with a higher PCE than the modified device. However, in contrast, the PSC device with the buffer layer only degraded a small amount. The best device maintained 95% of its initial efficiency after exposure for 550 hours.Item Statistical Optimization of Optical Property (Transparency) of Bleached, Oxidized Sucrose Cross-Linked Cassava Starch Film(AFIT Journal of Science and Engineering Research, 2022) J. Y. Jiya; J. S. Enaburekhan; M. T. Jimoh; E. C. Egwim; I. A. JosephThe present environmental pollution caused by non-degradable polymer films has prompted researches into the development of biodegradable polymer films. This study was able to develop a bleached, cross-linked film from native cassava starch. Hydrogen peroxide (H2O2) was added for bleaching to improve the transparency, oxidized sucrose was added for cross-linking and further oxidation while a moderated concentration of glycerol helps to improve the plasticity. In order to have a wider area of application of the film, the transparency was optimized using Box-Benkhen method under the response surface methodology (RSM) in Design Expert 11.0 software. UV-visible spectrophotometer analysis shows that the cassava starch film produced at the above process conditions retained 91.8 % of its transparency after 24 hours water immersionItem Thermal Stability, Transparency, and Water Sensitivity Properties of Bleached, Cross-Linked Cassava Starch Film(Journal of Digital Food, Energy & Water Systems (JD-FEWS), 2024) J. Y. Jiya; M. Abubakar; I. A. Joseph; E. C. Egwim; K. T. ObanimomoThis work investigates a novel study of the effect of bleaching and cross-linking cassava starch film. Native cassava starch was bleached with hydrogen peroxide (H2O2), cross-linking was carried out with oxidized sucrose, while glycerol was added to enhance the plasticity of the film. Operating temperature and time of 90 °C and 10 Minutes, respectively, adding 0.5 ml of glycerol gave the best bleached, cross-linked cassava starch film. UV-visible spectrophotometer analysis revealed that the cassava starch film produced at the above reaction conditions retained 88.2 % of its transparency at 96 hours of water immersion. The water solubility test shows that the film experienced 52.02 % weight loss after 96 hours of immersion in water. The thermo-gravimetric analysis (TGA) shows a significant improvement in the thermal stability with a Temperature peak (Tp) of 420.75 °C, compared to 374.13°C Tp of the control sample (unbleached, uncross-linked) of the cassava starch film.