Htigh-speed H-1 MAS NMR investigations of the weathered surface of a phosphate glass

Solid-state high-speed H-1 MAS NMR spectroscopy was used to investigate the weathered surface of a potassium aluminum phosphate (KAP) glass exposed to a humid environment (30K(2)O . 10Al(2)O(3) . 60P(2)O(5), mol%). Through the combination of spin-spin rela:cation and double quantum (DQ) filtering it was possible to resolve seven or eight different proton environments within the weathered surface of the KAP glass. Two-dimensional (2D) DQ and 2D NOESY NMR correlation experiments were performed to probe the spatial proximity of these different proton species. These H-1-H-1 correlation experiments helped confirm the spectral assignments. The analysis of these different H-1 environments provides additional information about the chemical processes that occur at the weathered glass surface. (C) 2004 Elsevier Inc. All rights reserved.