CELLULOSE WATER-VAPOR INTERACTION INVESTIGATED BY SPECTROMETRIC AND ULTRA-HIGH-FREQUENCY METHODS

The cellulose-water vapour interaction has been investigated by near-i nfra-red spectrometric and ultra-high-frequency (UHF) methods. Spectra revealed 1.363 and 1.423 mu m bands of cellulose surface hydroxyls an d transformation of these bands under the influence of adsorbed water molecules. The relation of the surface coverage theta to the sample's water content, the specific surface area of cellulose of about 90 m(2) g(-1) and surface hydroxyl density of 2.5 OH nm(-2) were obtained usi ng the simple model of hydroxyl arrangement on the inner surface of a cellulose fibre. Results of spectral and UHF measurements indicate tha t the saturation of hydrogen bonds of surface OH occurs at theta congr uent to 0.5. During the monolayer formation stage the UHF wave absorpt ion by molecules of adsorbed water is more than two times smaller than that for the phases of water on top of the monolayer. Surface paramet ers of cellulose are compared with those of divided silica.