Preferential Solvation Phenomena as Solute-Induced Structure-Making/Breaking Processes: Linking Thermodynamic...

Area of Science:

• Thermodynamics
• Statistical Mechanics
• Physical Chemistry

Background:

• Preferential interaction parameters quantify solute-environment interactions in mixed solvents.
• Understanding these interactions at a molecular level is crucial for predicting macroscopic properties.

Purpose of the Study:

• To establish rigorous macroscopic-to-microscopic links between thermodynamic preferential interaction parameters and microstructural descriptors.
• To develop a universal molecular-based signature for preferential solvation.
• To analyze the behavior of methane in aqueous 1,4-dioxane mixtures.

Main Methods:

• Statistical mechanical framework development.
• Analysis of total correlation function integrals.
• Characterization of structure making/breaking functions.
• Molecular simulations of ternary systems.

Main Results:

• Identification of explicit links between macroscopic parameters and microscopic structure.
• Development of a universal molecular signature for preferential solvation.
• Demonstration of the framework using methane solubility data.

Conclusions:

• The study provides a fundamental microstructural interpretation of macroscopic preferential interaction parameters.
• It highlights potential pitfalls in evaluating these parameters from molecular simulations.
• The findings offer a pathway for more accurate predictions of solution behavior.