Evidence for a hydrate of cellulose from studies of its surface properties
DURING an investigation of the surface properties of cellulose the relationship between the contact angle of water on cellulose and the water content of the cellulose was determined. The determination of the water-cellulose-air contact angle was done with the sessile drop method on regenerated cellulose films, and with the vertical rod method using thick cellulose fibres. (The model filaments of P. H. Hermans1). The contact angle of water on cellulose was determined at 20° C. in a gas phase consisting of air with a relative humidity with which the cellulose films and fibres of different water content were in equilibrium. Changes in the water content of the cellulose, ranging from 0 to 25.9 per cent absorption, were obtained by keeping the cellulose at 20° C. in air of different relative humidities varying from 0 to 95 per cent. © 1959 Nature Publishing Group.