Quantitative Modelling of Solvation in 2D Materials via Alchemical Decoupling and Potential Energy Surfaces

Abstract

Understanding why 2D materials remain suspended in solutions is essential to understanding the mechanisms of aggregation and exfoliation. These dynamics have been difficult to model because of the long timescales and large activation energies involved in these simulations. Here we describe an improved strategy for modelling the solvation and stability of 2D materials that uses the Gibbs free energy of solvation to accurately calibrate two disconnected potential energy surfaces for the fully desolvated and fully solvated 2D materials. By joining these surfaces using solvation energy, we obtain predictions for 2D material stability in various solvents that are qualitatively different than prior simulations and that have excellent agreement with experimental results. Our approach predicts a much higher barrier to full desolvation of the material, suggesting that materials that appear to be aggregated in fact still retain monolayers of solvent between adjacent layers of 2D materials. This work provides much needed understanding on the interactions between the solvent and 2D material that can guide future experimental work.