Composition – structure – property relationships in alkali aluminosilicate glasses: A combined experimental – computational approach towards designing functional glasses

Abstract

A set of 12 glass compositions with distinct structural features have been designed over a broad composition space in the per-alkaline region of the Na2O – Al2O3 – SiO2 ternary system. As expected from a per-alkaline system, aluminum has been found to be tetrahedrally coordinated in all the glasses using 27Al magic angle spinning – nuclear magnetic resonance (MAS-NMR) spectroscopy and from structure models generated using molecular dynamic (MD) simulations. The physical properties of glasses, for example, density, coefficient of thermal expansion (CTE), glass transition, elastic moduli and Vickers hardness and brittleness have been measured experimentally and their trends have been explained based on the atomic structure of glasses, from both simulations and experiments. A reasonable agreement has been observed between the composition – structure – property relationship trends obtained experimentally when compared with those predicted by MD simulations. This demonstrates that MD simulation is a promising technique for predictive modeling and designing novel glass compositions for functional applications.