Predicted structures of calcium aluminosilicate glass as a model for stone wool fiber: effects of composition and interatomic potential

Characterization of compositionally-complex aluminosilicate glass particles and fibers such as stone wool, and their interfaces with water and ions, is significant to a range of areas regarding dissolution phenomena. Knowledge of atomic level structures of these interfaces is critical to elucidating their dissolution traits. Molecular simulations can provide these details, complementing experimental efforts. However, prediction of the structure of stone wool fiber has been hampered by a lack of suitable inter-atomic potentials. Here, two candidate potentials are evaluated for their ability to recover experimental structural data of calcium aluminosilicate (CaO-Al2O3-SiO2) glass of compositions relevant to stone wool fibers. Both potentials produce structures that are broadly consistent with experimental data, including defect concentrations, aluminium avoidance, and ring size distributions, and either could provide a suitable basis for modelling dissolution of these materials.