Date of Completion
LIE, Montmorillonite, Molecular Dynamics
José A. Gascón
Robert R. Birge
Field of Study
Doctor of Philosophy
This study presents the use of the linear interaction energy (LIE) method as a predictive tool to approximate the free energies of sorption of organic cations to naturally occurring clay mineral montmorillonite. One objective of this thesis is to explore the applicability and the accuracy of LIE, originated in the biochemistry field, as a predictive tool to estimate the free energies of sorption of organic cations to naturally occurring aluminosilicates. For this purpose, a set of charged aromatic amines sorbing to a prototypical homoionic clay montmorillonite (MMT) with calcium ions were modeled using molecular dynamics (MD) simulations. As the LIE method enables the inclusion of both electrostatic and van der Waals interactions of the sorbate (organic cation) with the negatively charged aluminosilicate (sorbent), it provided a major improvement over existing predictive models which underestimates the sorption free energies due to exclusion of electrostatic interactions. Moreover, Use of MD simulations and electronic structure calculations provided atomistic level insight into the orientation of different organic cations inside the clay and their charge distribution. This thesis also explores the transferability of the derived LIE parameters as a function of different interlayer ions: Ca+2 and Na+ in MMT.
Samaraweera, Milinda A., "On the Use of the Linear Interaction Energy Method to Predict Affinities of Charged Aromatic Ammines to Naturally Occurring Clay Minerals" (2015). Doctoral Dissertations. 996.