Development of electrospinning process for nanofibres fabrication

• Main Author: Tang, Zi Sheng
• Format: Thesis
• Language: English; English
• Published: 2017
• Subjects: TA401-492 Materials of engineering and construction. Mechanics of materials
• Online Access: https://eprints.ums.edu.my/id/eprint/38890/1/24%20PAGES.pdf; https://eprints.ums.edu.my/id/eprint/38890/2/FULLTEXT.pdf; https://eprints.ums.edu.my/id/eprint/38890/
• Institution: Universiti Malaysia Sabah

Titanium oxide (TiO2) is a promIsIng semiconductor material with wide energy bandgap and it is extensively applied in dye-sensitised solar cells and photocatalytic devices. TiO2 nanofibre offers better electron transfer and hence it is vital to apply nanofibres in the solar cell to improve its efficiency. The study aims to produce electrospun TiO2 nanofibres using custom-made electrospinning system. The study focuses on the investigation of the operational parameters of the developed electrospi nning system on the fibres' diameter experimentally and using response surface methodology. A horizontal-oriented electrospinning system was developed to produce TiO2 nanofibres. Electrospun TiO2 nanofibres were produced from the ethanolic solution contains polymer carrier, polyvinylpyrrolidone (PVP), alkoxide precursor, titanium tetraisopropoxide (TTIP) and acetic acid as the stabiliser. TiO2 nanofibres with mean diameter range from 110±51 nm to 263±78 nm were produced based on the measurement using JMicroVision from scanning electron microscope (SEM) micrographs. Crystalline TiO2 nanofibres with anatase-rutile phases were established after the calcination process in the furnace for 3 hours at 450 °C and the TiO2 phases were confirmed with X-ray diffractometer (XRD). The relationship between fibre diameters and various parameters were investigated, such as supplied voltage, feeding rate, tip-to-collector distance, the rotation speed of custom-made drum collector and solution concentration. The PVP concentration was added from 4 to 9 wt. % and caused the average fibre size increased as much as 124%. It is also observed that increase in feeding rate resulted in elevating the fibres diameter. On the other hand, a reduction of 27% in fibres diameter occurred with an increment of tip-to-collector distance from 6 to 14 cm. Shrinkage of the fibre diameter occurred when the applied voltage increased. However, the rotation speed of drum collector had no significant effect on the fibres size. At the same time, a response surface model was developed by considering the variables of applied voltage, flow rate and tip-to-collector distance to estimate the fibres diameter. Based on the response surface plots, tip-to-collector distance is the most significant factor which contributed up to 66% influence in determining the fibres diameter. Whereas applied voltage plays a less weighty role at approximately 8% of influence in fibres diameter prediction.