Community Research and Development Information Service - CORDIS

Assessment of markers of damage for wool fibres using surface chemical analysis

X-ray Photoelectron Spectroscopy (XPS) of the wool fibre surfaces has established trends in the atomic ratios and chemical states of elements due to accelerated and natural ageing. A decrease in carbon is typically accompanied by an increase in oxygen, which can be attributed to the oxidative loss of surface lipids. This was confirmed by ToF-SIMS analysis where a decrease in the signal intensity (m/z 341-) for the covalently bound surface fatty acid (18-MEA) was observed in aged samples. Covalent cystine disulphide bonds cleave to form cysteic acid due to oxidative ageing; this is a major cause for strength loss in wool. For unaged wool samples it was found that >60% of the total surface sulphur content was unoxidised (cystine disulphide, cysteine or thioester protein-lipid linkages), whereas in accelerated aged and historic samples >60% of surface sulphur was oxidised to cysteic acid.

In general the relative % of oxidised sulphur and the C/O ratio at the fibre surface can be related to the reduction in tensile strength when comparing the unaged to the accelerated aged samples. XPS analysis also indicated that the majority of tested historic fibres have degraded further than the accelerated aged fibres.

Related information

Reported by

The University of Manchester
School of Materials
United Kingdom
Follow us on: RSS Facebook Twitter YouTube Managed by the EU Publications Office Top