Solvent-Mediated Interactions Close to the Fisher-Widom Line

Area of Science:

• Physical Chemistry
• Statistical Mechanics

Background:

• Understanding effective interactions between particles is crucial in fluid theory.
• The supercritical regime and critical lines (Fisher-Widom, Widom) exhibit unique solvent behaviors.

Purpose of the Study:

• To investigate the effective interactions between two hard spheres.
• To analyze these interactions within a square-well fluid.
• To focus on behavior near the Fisher-Widom and Widom lines in the supercritical regime.

Main Methods:

• Classical density functional theory (DFT) is employed.
• The potential distribution theorem is utilized for calculations.

Main Results:

• Effective interactions are calculated using DFT and the potential distribution theorem.
• The study analyzes how solvent correlations change from monotonic to oscillatory near critical lines.
• Behavior near the Fisher-Widom and Widom lines is characterized.

Conclusions:

• Classical DFT provides a framework to study effective interactions in complex fluid systems.
• The behavior of effective interactions is sensitive to solvent critical phenomena.
• Further research can explore these interactions in different fluid models.