1—the Swelling of Merino-Wool Fibres by Large Anions and by Water: Part I. A Study of the Swelling of Chosen Cross-Sectional Planes by the Measurement of Diameters

The cross-sectional swelling of individual wool fibres by water has been studied before and after the incorporation of large detergent anions of two types into the fibres. These additives reduce the regain of wool at all values of r.h. Although their presence itself produces a large swelling, the saturation swelling produced by water is little changed, which indicates a that the reduction in regain is not due to ‘pre-swelling’ and b that these additives are located in positions such that the swelling they produce does not strain the bonds that limit the swelling that can be produced by water. The measurements support the deduction from other observations that the anions are adsorbed onto the basic groups in the wool and displace predominantly tightly bound water. Some textile effects are discussed.