WATER IN ALBITE GLASSES - OH-GROUPS, ISOLATED MOLECULES, AND CLUSTERS

Four chemical proton states were determined in hydrous albite glasses prepared by quenching of albite melts at high pressures and temperatur es and were investigated by NMR. The protons of the isolated water mol ecules are displayed by Fake's doubler in the H-1 NMR spectra. The sec ond type of proton causes the central line. This peak in the spectra o f glasses with total water content up to 50 mol% is produced by OH-gro ups associated with Na. With an increase of the water content, at the threshold value, apparently the protons of the water cluster are forme d. The fourth type is observed in the sample with the highest water co ntent as protons of liquid state micropores water, generated during qu enching. (C) 1998 Elsevier Science B.V.