Oxygen Speciation in Multicomponent Silicate Glasses Using Through Bond Double Resonance NMR Spectroscopy

Area of Science:

• Materials Science
• Solid-State Chemistry
• Spectroscopy

Background:

• Aluminosilicate glass structure is often described by its cations, with oxygen ions dictating connectivity and influencing material properties.
• Determining short- to medium-range order in these disordered materials is crucial for understanding their behavior.
• Traditional ¹⁷O NMR methods provide limited speciation for multicomponent glasses.

Purpose of the Study:

• To directly probe through-bond correlations in multicomponent aluminosilicate glasses.
• To overcome the ambiguous speciation of chemical bonds in complex glass systems.
• To quantify overlapping spectral components in ¹⁷O NMR spectra.

Main Methods:

• Utilized ¹⁷O{²⁷Al} and ¹⁷O{²³Na} solid-state nuclear magnetic resonance (NMR) double-resonance experiments.
• Applied advanced NMR techniques to analyze quaternary aluminosilicate glass.
• Focused on exploring through-bond correlations, a scarcely investigated area.

Main Results:

• Successfully quantified overlapping components within the ¹⁷O NMR spectra.
• Observed a cooperative arrangement of alkali and aluminum ions near bridging oxygens.
• Provided direct evidence of through-bond correlations in aluminosilicate glasses.

Conclusions:

• The observed ion distribution supports the modified random network model for glass structure.
• The study validates the use of ¹⁷O NMR double-resonance experiments for detailed structural analysis.
• Findings enhance the understanding of structural heterogeneity in aluminosilicate glasses, distinguishing between network and channel regions.