Sorption of water by wool

A model for the system of wool plus sorbed water is proposed in which the sorbed water consists of three distinct molecular species: localized water irrotationally bound to localized sites in the fiber, mobile water with properties identical to bulk water, and intermediate water with a potential energy of sorption between that of the localized and mobile water. The theoretical isotherm for this system has been determined from statistical considerations and compared with the experimental isotherm for wool reduced to one hydrostatic pressure. The statistical parameters of the model have been evaluated thereby and the distribution of the sorbed water among the three energy states inferred. The nature of the localized sites and the properties of the sorbed water are discussed. The model is applied to the interpretation of data on the microwave dielectric behavior of wool–water systems, the heat of wetting of wool, and the effects of sorbed water upon the elastic properties of the fiber.