Synthesis, characterisation and application of organic nanowires

• Main Author: Lee, Daryl Weilun
• Other Authors: School of Materials Science and Engineering
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Materials::Nanostructured materials
• Online Access: http://hdl.handle.net/10356/55805
• Institution: Nanyang Technological University

Thermoelectric materials provide a potential solution for an alternative energy source. On top of generating electricity, thermoelectric materials can also be used to provide a cooling effect as well. Organic thermoelectric materials have many advantages over their inorganic counterpart, such as flexibility and weight. Although current organic thermoelectric materials have much lower efficiencies, high values have been predicted using a quasi-one dimensional physical model. The objective of this project is to determine the dopants and morphologies which enhance the efficiency of organic thermoelectric materials. Polyaniline nanowires and polypyrrole nanotubes were synthesised and doped with acetic acid, hydrochloric acid and p-toluenesulfonic acid. The thermoelectric properties, which consist of electrical conductivity, Seebeck coefficient and thermal conductivity, were tested using appropriate equipment. The thermoelectric figure of merit, ZT, was then calculated and compared. Results show that for polyaniline nanowires, the highest value of ZT was attained when doped with 0.5 M p-toluenesulfonic acid. For polypyrrole nanotubes, the highest value of ZT at room temperature was obtained when doped with 0.5 M HCl. Polyaniline nanorods and nanowires were also compared, which showed that the nanowires had a ZT value 5 times greater than the nanorods.