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

Abstract

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, 11B 2D DQ-SQ NMR spectra were edited to monitor the formation of the borate network through [x]BO[x]B linkages. In a second time, 11B(31P) D-HMQC technique was applied to characterize the formation of [x]BOP bonds and to provide additional information used to decompose the 1D 31P 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.