Microinhomogeneity of high-alkali aluminosilicate glasses studied by nuclear magnetic resonance spectroscopy

The structure of quenched aluminosilicate glasses with Na₂O/Al₂O₃ > 1 has been studied by high-resolution nuclear magnetic resonance spectroscopy. The aluminum in the structure of the glasses is shown to be in fourfold coordination. Increasing the sodium oxide content of the glasses reduces the degree of polymerization in their structure and leads to a nonuniform nonbridging oxygen distribution over the aluminosilicate glass network. The glasses have a locally microinhomogeneous structure due to the presence of both highly polymerized aluminosilicate anion groups and relatively depolymerized silicate anions.