Investigation of phase transitions in adsorbed water by NMR

A study of sorbed water on cellulose by the thermally stimulated depolarisation technique

“…According to Kent and Meyer (1983) one might expect to have layers of water molecules with the energy of binding decreasing with the distance from the substrate surface and approaching the pure water value in the limit. However, the anomalous properties of sorbed water observed in cellulose and in other organic and inorganic materials (anomalous in the sense of being different from those of macroscopic pure water) may be considered from another point of view as a general property of highly dispersed matter (Kvlividze and Kiselev 1967). The structure of water in films or clusters in hydrated materials is determined largely by surface conditions.…”

Wetting Films

“…10.12 that, in the absence of a gel layer, the thickness of the water film on the quartz surface tends to a monolayer at p/ps ~ 0.9. Kiselev and Kvlividze [96] have demonstrated that clusters of water molecules separated by "dry" areas are formed on the surface at the value of adsorption that formally corresponds to one monola¥er coverage. The clusters merge when film thickness exceeds 10 A, when the film can already be regarded as a continuous polymolecular coating, i.e., as a truly wetting film.…”

“…When film thickness is much less than the height of surface rough-ness relief fi, the influence of roughness is revealed only via the roughness coefficient, and this factor cannot modify the law of interaction but can only change the value of measured thickness. When h is comparable to fi, surface roughness becomes capable of changing the shape of isotherms as well, the type of changes being dependent on the shape of asperities [96].…”