OXYGEN SITES IN SILICATE GLASSES: A NEW VIEW FROM OXYGEN-17 NMR

Abstract

Nuclear Magnetic Resonance (NMR) studies of 17O in silicate glasses is beginning to provide new information on structure from an ''anionic'' viewpoint, which is an important complement to more traditional discussions of cation coordination and connectivities. A variety of techniques are discussed here, but the most important recent advances have used the new, two-dimensional, high resolution techniques of Dynamic Angle Spinning (DAS) and Triple Quantum Magic Angle Spinning (3QMAS), which have resolved and distinguished peaks for bridging oxygens linking Si, Al and B cations, as well as non-bridging oxygens. These approaches have provided some of the first quantitative constraints on the extent of ordering, both among network modifier cations and among network former cations.