Advanced solid state 1D/2D NMR investigation of the B2O3-Zn(PO3)2 glasses

In order to understand how the B2O3 insertion alters the structure and properties of the widely used zinc metaphosphate glass composition, advanced 1D/2D solid state MAS-NMR techniques were applied in this contribution to B2O3-Zn(PO3)(2) glasses. High field (18.8 T) 1D NMR experiments allowed for a detailed characterization of the borate local order but did not provide much information about the phosphate speciation. We show how a set of 2D correlation NMR techniques could be applied to obtain additional data. First, B-11 2D DQ-SQ NMR spectra were edited to monitor the formation of the borate network through B-[x]-O-B-[x] linkages. In a second time, B-11(P-31) D-HMQC technique was applied to characterize the formation of B-[x]-O-P bonds and to provide additional information used to decompose the 1D P-31 MAS-NMR experiments. This first 1D/2D NMR analysis of the B2O3-Zn(PO3)(2) line was finally used to construct a structural model which shed light upon the glass transition temperature non-linear evolution.