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High-pressure Sapphire Cell for Phase Equilibria Measurements of CO2/Organic/Water Systems
Published on: January 24, 2014
Communication: Direct determination of triple-point coexistence through cell model simulation
Vincent R Heng1, Michael Nayhouse, Marquis Crose
1Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, USA.
The Journal of Chemical Physics
|October 16, 2012
Summary
This study models fluid-solid coexistence using a generalized cell model, linking disordered and ordered phases. Simulations reveal a higher triple-point pressure for the Lennard-Jones system, likely due to gas compressibility.
Area of Science:
- Computational physics
- Thermodynamics
- Statistical mechanics
Background:
- The constrained cell model simplifies fluid-solid coexistence simulations.
- A generalized cell model bridges fluid and solid phases using an external field.
- Understanding phase transitions is crucial in materials science.
Purpose of the Study:
- Investigate the phase diagram of the generalized cell model.
- Determine the triple point of the Lennard-Jones system.
- Analyze the influence of gas compressibility on phase behavior.
Main Methods:
- Multicanonical simulations at constant pressure.
- Histogram reweighting techniques.
- System of 256 Lennard-Jones particles.
Main Results:
- The phase diagram of the generalized cell model was mapped.
- An estimate for the triple-point pressure of the Lennard-Jones system was obtained.
- The calculated triple-point pressure is higher than previously reported values.
Conclusions:
- The generalized cell model effectively links fluid and solid phases.
- The discrepancy in triple-point pressure is attributed to gas phase compressibility.
- Further research may refine phase transition predictions.
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