Date of Completion


Embargo Period



LIE, Montmorillonite, Molecular Dynamics

Major Advisor

José A. Gascón

Associate Advisor

Robert R. Birge

Associate Advisor

Allison MacKay

Associate Advisor

Alfredo Angeles-Boza

Associate Advisor

Fatma Selampinar

Field of Study



Doctor of Philosophy

Open Access

Open Access


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.