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Self-diffusion and structural properties of confined fluids in dynamic coexistence
N de Sousa1, J J Sáenz, Frank Scheffold
1Departamento de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain.
Summary
In confined Lennard-Jones fluids, self-diffusion varies significantly between solid and liquid phases during dynamic coexistence. However, radial distribution functions remain nearly identical across these phases at constant temperature.
Area of Science:
- Thermodynamics
- Statistical Mechanics
- Materials Science
Background:
- Confined fluids exhibit unique phase behaviors.
- Understanding solid-liquid coexistence is crucial for materials science.
- Lennard-Jones potential is a standard model for interatomic interactions.
Purpose of the Study:
- Investigate self-diffusion and radial distribution functions in strongly confined Lennard-Jones fluids.
- Analyze dynamic coexistence phenomena at the solid-liquid phase transition.
- Correlate transport properties with structural characteristics under confinement.
Main Methods:
- Molecular dynamics simulations were employed.
- Lennard-Jones potential was used to model interatomic forces.
- Analysis focused on self-diffusion constants and radial distribution functions.
Main Results:
- Self-diffusion constants showed up to three-fold variations between solid and liquid phases.
- These variations occurred within the dynamic coexistence region at fixed temperatures.
- Radial distribution functions were found to be nearly indistinguishable for both solid and liquid phases.
Conclusions:
- Strong confinement leads to significant differences in dynamics (self-diffusion) despite similar structures.
- Dynamic coexistence in confined systems can mask underlying structural similarities.
- This highlights the complex interplay between structure and dynamics in confined fluids.
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