Composition-structure-property relationships in Li2O–Al2O3–B2O3 glasses

Abstract

The past decade has brought borate glasses to the forefront of industrial and technological innovations with the development of resorbable bioactive glasses for tissue engineering, glasses for immobilization of hazardous wastes and crack-resistant glasses for electronic packaging. However, these applications warrant a deeper understanding of the structural origin of various thermal, chemical and physical properties of borate glasses. Furthermore, the combination of borate glasses with SiO2 results in the formation of borosilicate glasses – one of the most important glass systems from scientific, technological and commercial viewpoints. In fact, it has been shown that most structural features in alkali borosilicates are similar to those of alkali borates. It is therefore important to understand the composition–structure–property relationships in borate-based glass compositions before extending them to more complex borosilicates, or aluminoborosilicate systems. In particular, aluminoborate glasses are intriguing as composition-structure-property models in these glasses are still under-developed. Accordingly, this paper is a sequel of our previous article [J. Non. Cryst. Solids. 460 (2017) 54–65] where we investigated the molecular structure of glasses in the system 25Na2O–xAl2O3–(75–x)B2O3 (x varies from 0 and 25 mol%) using magic angle spinning – nuclear magnetic resonance (MAS-NMR) and Raman spectroscopy. Further, the trends observed for the properties of these glasses, for example, density, molar volume, glass transition (Tg), coefficient of thermal expansion (CTE) and chemical durability (in water) have been correlated and discussed on the basis of their molecular structure.