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

The use of 1H–31P cross-polarization (CP)-edited radio frequency dipolar recoupled (RFDR) two-dimensional (2D) NMR exchange experiments for the study of surface dissolution species in solution-aged metaphosphate glass is reported. It is demonstrated that use of CP allows the resonances of phosphate tetrahedral species within the hydrated dissolution surface to be selectively and cleanly edited from the bulk unaged phosphate species. Incorporating 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.