Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2006. / Dyeing has an influence on the characteristic properties of wool fibres. This can result in
changes in the final properties of the fibre including fibre elasticity, fibre strength and
breaking elongation of the wool fibres, especially in the case of dark colours. Damage
that occurs to the fibre surface due to the action of acid, alkali, dyestuff, water, heat, and
mechanical stress during the dyeing process can thus have an affect on the fibre breaking
elongation and the fibre strength. The aim of this project was to assess the effect of
dyeing with different colours (ranging from light to dark) on the surface of wool fibres
using atomic force microscopy (AFM).
The results indicated that four different types of surface damage can be discerned: scale
raising, scale chipping, fluting and pitting. The findings also indicate that the surface
damage to the fibres was greater and more noticeable (especially the scale raising) on
fibres dyed with dark colours than to fibres dyed with light colours. The same applied to
the fibre strength and elongation, where generally the fibre breaking extension and the
breaking load was smaller in the case of darker colours.
The effect of dyeing with different colour shades on the fibre surface was observed with
AFM. Several characteristic scale parameters of a statistical significant number of dyed
and undyed fibres were measured in order to determine the surface damage caused by
dyeing. The correlation between the surface damage, observed by AFM, and the loss in
tensile strength and fibre elongation, determined by tensile tests, were investigated. This
was done in order to determine the effect of the cuticle damage on the tensile stress/strain
behaviour. The results show that AFM is a viable tool to study the effects of different
dyes on the fibre surface and for detecting surface modifications with great accuracy.
It was found that dyeing with dark colours caused greater damage to the surface than
light colours, and it was possible to distinguish different lightness areas, which could be
regarded as light and dark colours.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/2388 |
| Date | 03 1900 |
| Creators | Abduallah, Abduelmaged |
| Contributors | Meincken, M., Gericke, A., University of Stellenbosch. Faculty of Science. Dept. of Chemistry and Polymer Science. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | University of Stellenbosch |
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