Estimating the activation energy of bond hydrolysis by time-resolved weighing of dissolving crystals

Bond-breaking activation energy E-B is nowadays a key parameter for understanding and modeling crystal dissolution processes. However, a methodology to estimate E-B based on classical dissolution experiments still does not exist. We developed a new method based on the calibration of a Kossel type dissolution model on measured dissolution rates obtained by mass (or volume) variations over time. The dissolution model does not depend on the geometry of the crystal surface but only on the density of the different types of sites (kink, step, terrace, bulk). The calibration method was applied to different experimental setups (flow through and batch) with different ways of estimating the dissolution rates (solute concentration in the fluid, surface topography) for calcite crystals. Despite the variety of experimental conditions, the estimated bond-breaking activation energies were very close to each other (between 31 and 35 kJ/mol) and in good agreement with ab initio calculations.

Automated summary

The study developed a new method to estimate the bond-breaking activation energy during crystal dissolution processes based on experimental data, with the results showing good agreement across different experimental setups. The estimated bond-breaking activation energies were found to be close to each other and in line with ab initio calculations, demonstrating the effectiveness of the proposed method.