- Title
- The effect of gamma radiation on the physical and chemical properties of wool
- Creator
- Rapakgadi, Jim
- Subject
- Semiconductors -- Effect of radiation on
- Date Issued
- 2020
- Date
- 2020
- Type
- Thesis
- Type
- Doctoral
- Type
- PhD
- Identifier
- http://hdl.handle.net/10948/47668
- Identifier
- vital:40263
- Description
- Pathogens (e.g. viruses, spores and bacteria) remain one of the biggest threats to trading and the economy of natural fibre products, such as wool, mohair and cotton. One of the means to kill or eliminate pathogens is by radiation sterilisation, involving electromagnetic radiation (e.g. gamma radiation and UV light). The research, reported in this thesis, was aimed at establishing the effect of gamma irradiation dosage on the various quality related physical and chemical characteristics of four different types of merino wool when treated in situ in scoured and greasy state in mini-bale form. Specific properties studied include wool colour (yellowness and brightness), solubility (alkali solubility and urea bisulphite solubility), fibre diameter and tensile properties (staple strength and bundle tenacity). Standard analytical and diagnostic techniques were used to assess changes, if any, in the above mentioned properties due to the radiation treatment. Nominal radiation dosages, ranging from 25 kGy to 75 kGy (actual measured from 0 kGy to 92.2 kGy) were used, 50 kGy normally being regarded as sufficient to destroy the pathogens in question. It was found that nominial gamma radiation dosages of up to 92.2 kGy did not significantly affect fibre diameter or staple length, indicating that no irreversible swelling of the wool fibres occurred as a result of gamma irradiation. Alkali and urea bisulphite solubility as well as yellowness, on the other hand, showed a systematic increase with an increase in irradiation dose, indicating that changes occurred at molecular level. Fibre tensile properties (staple strength and bundle tenacity) were also affected but to a much lesser extent than solubility and colour. The various merino wool types studied showed similar reactions to the radiation treatment, irrespective of the wool quality and type and also whether they were treated in greasy or scoured form.
- Format
- xii, 131 leaves
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
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Collections
NMU School of BioMolecular and Chemical Sciences
| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Rapakgadi, J 206850170 Thesis April 2020.pdf | 2 MB | Adobe Acrobat PDF | View Details Download |