Thermodynamic properties of quasi-one-dimensional fluids

Area of Science:

• Physics
• Physical Chemistry
• Materials Science

Background:

• Confined fluids exhibit unique thermodynamic and structural properties.
• Understanding hard sphere fluid behavior in quasi-one-dimensional pores is crucial for various applications.

Purpose of the Study:

• To calculate thermodynamic and structural quantities of hard sphere fluids in quasi-one-dimensional pores.
• To develop a perturbative method applicable to confined fluids.

Main Methods:

• Applying a perturbative method for confined fluids in slit pores.
• Transforming the problem into an effective one-dimensional fluid of interacting rods.
• Calculating effective k-body potentials and the free energy of the effective fluid.

Main Results:

• Demonstrated that confined hard sphere fluid properties can be derived from an effective 1D rod fluid.
• Explicitly calculated two- and three-body potentials for the rod fluid.
• Calculated the free energy up to leading order in (W/σ)2.
• Presented results for perpendicular pressure, surface tension, and density profiles.
• Validated results against Monte Carlo simulations and virial expansions.

Conclusions:

• The perturbative method accurately captures thermodynamic and structural properties of confined hard sphere fluids.
• The approach successfully describes the singularity at the jamming transition point.
• This method provides a robust framework for studying fluids in quasi-one-dimensional confinement.