Pilar Erra

In this study, a set of experiments was carried out with the aim of gradually conferring hydrophobic properties to a low temperature plasma-treated wool fiber surface by post-reaction with hydrocarbon chains of different chain length. This study revealed the close relationship between the hydrophobic/hydrophilic properties of the wool surface with its shrinkage properties.

Extraction selectivity of whole wool wax from raw wool by using ethanol‐modified carbon dioxide at constant pressure (100 bar) and temperature (60°C) was studied. A kinetic study was carried out to optimize the percentage of ethanol and the extraction time. The modified carbon dioxide was decompressed in ethanol as a collection solvent, leading to the formation of two different fractions as a function of their solubility. Qualitative and quantitative analyses of the lipid classes present in the collected fractions were performed by TLC coupled to an automated FID system (TLC‐FID). Moreover, a detailed structural comparison was carried out between the aliphatic high‐molecular‐mass esters and the steryl ester patterns by means of subambient pressure GC‐MS in both the EI and the ammonia positive Cl modes. Considerable differences in the lipid composition of the two wool wax fractions collected were observed by TLC‐FID and GC‐MS.

The effect of water vapour plasma treatment on the shrinkage behaviour and chemical properties of the surface of keratin fibres was studied. The wettability and shrink resistance of wool were improved even at low plasma treatment times. The values of the advancing contact angles of keratin fibres treated with plasma provide evidence of the formation of hydrophilic groups in the wool surface. Analysis by XPS reveals that oxidation of the fatty acid monolayer (F‐layer) prevails over its removal in the early stages of plasma treatment. The increase in treatment time results in a progressive removal of the F‐layer. Copyright © 2003 John Wiley & Sons, Ltd.