Probing dissolution surface structure in phosphate glasses using H-1-P-31 cross-polarization edited radio frequency dipolar recoupling experiments

The use of H-1-P-31 cross-polarization (CP)-edited radio frequency dipolar recoupled (RFDR) two-dimensional (2D) NMR exchange experiments for the stud y of surface dissolution species in solution-aged metaphosphate glass is re ported. It is demonstrated that use of CP allows the resonances of phosphat e tetrahedral species within the hydrated dissolution surface to be selecti vely and cleanly edited from the bulk unaged phosphate species. Incorporati ng the CP-editing into a 2D RFDR exchange experiment also allows the local spatial connectivity between these surface dissolution phosphate species to be directly addressed. (C) 2001 Published by Elsevier Science B.V.