Study of the surface energy of montmorillonite using PACHA formalism

The surface energy of exchanged forms of montmorillonite has been computed using a partial charge model introduced in the calculation of the lattice energy. The results are in correct agreement with data on heats of adsorption. However, the difference between theoretical and experimental data increases from light cations to heavy cations associated with the clay network. This indicates that the heat of adsorption depends highly on the step hydration of the cations. This type of behavior was expected and thus the quantification seems realistic.

In this paper, we focus on montmorillonite substituted with first column cations in our studies of the surface energy of clays. Heats of immersion and calculations of solid surface energy are linked in view of comparison of results. Data and calculations follow the expected trends and allow the prediction of hydration heats of the various cations.Figure optionsDownload as PowerPoint slide