Structural evidence of mixed alkali effect for aluminoborosilicate glasses

The structure of mixed alkali aluminoborosilicate is quite difficult to explain due to the mixed alkali effect and interaction between multiple network formers, intermediate oxides, and network modifiers. To understand the complex behavior of these components in mixed alkali glasses, solid-state MAS NMR and Raman spectroscopy were performed. Various Raman peaks were specifically revealed, and all of which were highly associated with the degree of polymerization (DP) obtained by deconvolution of 800-1200 cm(-1). A systematic change of the glass network was well explained to be a consequence of a strong relationship between DP and MAS NMR results of network formers (Al-27 and B-11). When alkali cations were mixed, a new characteristic of mixed alkali effect, an increase in charge compensation stability between AlO4 and smaller cation, was first observed from high correlation between full width at half maximum (FWHM) of network modifiers (Li-7 and Na-23) and MAS NMR data of network formers. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The structure and behavior of mixed alkali aluminoborosilicate glasses were studied using solid-state MAS NMR and Raman spectroscopy. The correlation between Raman peaks and polymerization degree, as well as the relationship between MAS NMR results of network formers and the glass network changes, were revealed. The mixed alkali effect was observed to increase the charge compensation stability between network modifiers and network formers.