Abstract:
Sorption of materials onto surfaces, is an important field of chemistry, where much remains to be learned. A large part of the problem lies in the interpretation of experimental data obtained.
If a given material is exposed to an atmosphere containing water vapour, then under constant external conditions the material will attain a moisture content, that remains constant. This equilibrium is not static, but is the result of a dynamic equilibrium between water vapour condensing and water evaporating from the sorption sites on the material concerned. For textile fibres, it is not only the molecular composition of the fibres that determines the moisture regain but also the geometric arrangement of the groups. There is evidence that only parts of the fibre are freely accessible to water, Hermans, P.H.and Weidinger, A., J. Polymer Sci., 4, 135, 317, (1949), Hermans, P.H. and Weidinger, A., J. Polymer Sci., 5, 656, (1950) and that the regions of crystallinity are inaccessible. Thus the number of hydrophilic groups and their accessibility, are most important in determining the amount of water sorbed, and the shape of the sorption isotherm for any fibre.
