Topological model of the dissolution kinetics of silicate glasses

Understanding and predicting the dissolution rate of silicate glasses is of primary importance for various applications, including bioactive glasses and borosilicate wasteforms. However, the mechanism of silicates’ dissolution – and its rate-limiting step – remains poorly understood. In particular, present models linking the composition and structure of silicate glasses to their dissolution rate in a given solvent have remained largely empirical thus far. Here, based on vertical scanning interferometry (VSI), we study the dissolution of a family of borosilicate glasses under several values of pH. In addition, we parametrized a new transferable inter-atomic potential to assess the structure of these glasses from molecular dynamics (MD) simulations. From a detailed analysis of the simulated structures, we demonstrate that the kinetics of the dissolution is controlled by the topology of the atomic network. Finally, we propose a new topological model of the dissolution, which is shown to offer realistic predictions of the activation energy of dissolution for a wide selection range of silicate glasses and crystals.