Harnessing Exotic Structural Motifs in Borosilicate Glasses for Improved Structural Models

Borosilicate (BS) based glasses have numerous important applications, ranging from kitchen glassware to biomedical implants, radioactive waste encapsulation, and substrates for flat-screen displays.

For the purpose of improving the structural description of BS glasses and assisting a future rational design of such glasses with tailor-made properties, we will combine results from advanced solid-state NMR (ssNMR) experiments and atomistic molecular dynamics (MD) simulations applied to BS glasses that incorporate different alkali- and alkaline-earth metal ions.

Our studies target both the short- and medium-range (3-7 Å) BG glass structure, and notably so the exploration of some “exotic” structural motifs—such as directly interlinked BO4 groups and non-bridging O (NBO) species at BO4 (B[4]-NBO bonds)—which are ignored in current BS glass-structure models.

By studying several BS glass systems with different network modifiers, we will improve the insight into how the amounts of the “exotic” structural motifs depend on the size and charge of the modifier cations, as well as if/how they influence the glass properties. This will lead to an improved BS glass-structure theory/model and new composition-structure-property relationships.

We will also develop novel 17O-based ssNMR methods for an enhanced probing of the various O environments in BS glass networks. The methods will be applicable to a wide range of oxide-based glasses.