A note on the thermodynamic properties and infra-red spectra of sorbed water

Abstract

ce the fundamental basis of the heterogeneous nucleation of ice must lie in the ure of the interaction between water molecules and the nucleating solid and sidering the interest in the infra-red properties of water shown in this discusion it appears appropriate to make a preliminary comment on some of our ent studies on water-aluminosilicate systems. nvestigations are being made on the heat capacity, heats of sorption and a-red absorption spectra of water in the cages of a synthetic zeolite (Linde pe A) as a function of its water content. The crystal structure of this zeolite ed & Breck 1956) shows it to contain a system of cages bounded by six- mbered and eight-membered aluminosilicate rings. Each unit cell contains large, approximately spherical cavity, 11.4 Å in diameter, which can hold proximately 21 water molecules at saturation. The structure can be progres- sly dehydrated or rehydrated without causing lattice collapse, and thus we have, possibility of investigating the properties of a cluster of water molecules ying in size from 1 to 21 molecules. Furthermore, since exchangeable cations associated with the anionic lattice we can examine the influence on this sorbed ter of the change in cation type while retaining the anionic framework changed.