E-Thesis 164 views
Upcycling potential of waste carbonaceous feedstock to carbon nanotubes / Ioannis Tsampanakis
Swansea University Author: Ioannis Tsampanakis
Abstract
The overarching problem of plastic pollution perturbing our ecosystems along with the need for inexpensive feedstock material have turned scientists’ research focus to plastic waste. In this work, the feasibility of various plastic waste streams as carbon feedstock for carbon nanotubes (CNTs) was as...
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Swansea, Wales, UK
2023
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| Institution: | Swansea University |
| Degree level: | Master of Research |
| Degree name: | MSc by Research |
| Supervisor: | Alexander, Shirin. and Andreoli, Enrico. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa64894 |
| Abstract: |
The overarching problem of plastic pollution perturbing our ecosystems along with the need for inexpensive feedstock material have turned scientists’ research focus to plastic waste. In this work, the feasibility of various plastic waste streams as carbon feedstock for carbon nanotubes (CNTs) was assessed both theoretically and experimentally. The three main plastic waste streams were comprised of medical plastic, fridge and car plastic. In the first project (Chapter 2), waste ostomy bags were dissolved in H2SO4 at 43 wt.% and 96 wt.%. The low H2SO4 concentration had minimal effect towards the materials of the ostomy bag whereas the high H2SO4 concentration effectively dissolved three of the bag’s components due to increased concentration of H+ ions. Based on the acid dissolution results, further dissolution tests were proposed towards achieving a higher percentage of dissolved ostomy bag material. Moreover, electrochemical cell set ups were proposed in order to succeed towards the growth of CNTs from the waste ostomy bags. In all proposed set ups, Nickel was chosen as the catalyst due to its face centered cubic nature, which is compatible with graphene and forms strong and stable bonds. Sodium sulphate as the best electrolyte and a constant current density of 7-8 mA∙cm-2 were theoretically determined to create a suitable environment towards the selective growth of CNTs over other carbon-based nanomaterials. A process map of each step was developed to aid further testing in this project. For the second project (Chapter 3), theoretical and experimental dissolution tests using various organic solvents were performed for fridge (WEEE) and car waste plastic, aiming to find the optimum solvent for each case. The fridge plastic waste was in a form of powder, whereas for the automotive waste, the waste came from different streams and was in various forms. The effects of different organic solvents and solvent blends were tested both theoretically and practically towards dissolving the waste fridge powder. M-cresol and cyclohexanone: ethanol: m-cresol (40:20:40) were determined as the best solvent and solvent blend, respectfully. Regarding the automotive waste plastics, dissolution tests were performed in toluene under reflux with two samples showing promising results. Finally, CNTs of o.d. 62.24 ± 12.73 (std. dev.) nm were grown from fridge plastic waste as a proof of concept, while the practicality of growing nanomaterials from the other plastic types was evaluated. |
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| Keywords: |
Waste plastic, upcycling, carbon nanotubes |
| College: |
Faculty of Science and Engineering |
| Funders: |
KESS, TrimTabs (Industrial partner) |