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10:11
Cell Co-culture Patterning Using Aqueous Two-phase Systems
Published on: March 26, 2013
Communication: phase transitions, criticality, and three-phase coexistence in constrained cell models
Michael Nayhouse1, Joseph Sang-Il Kwon, G Orkoulas
1Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, USA.
The Journal of Chemical Physics
|June 7, 2012
Summary
This study models the solid phase in fluid-solid transitions using a constrained cell model. The constrained Lennard-Jones system shows higher critical and triple points due to reduced entropy.
Area of Science:
- Computational physics
- Materials science
- Statistical mechanics
Background:
- Fluid-solid transitions are crucial in many physical systems.
- The Wigner-Seitz cell model is commonly used to represent the solid phase.
- Previous studies utilized thermodynamic integration for phase coexistence determination.
Purpose of the Study:
- To determine the phase diagram of a constrained system of Lennard-Jones particles.
- To investigate the mechanical stability limits of the solid phase.
- To compare the phase behavior of constrained versus unconstrained systems.
Main Methods:
- Constant-pressure simulations were employed.
- Lennard-Jones particles were used as the model system.
- Pressure-density isotherms were analyzed to identify inflection points.
Main Results:
- Inflection points on pressure-density isotherms indicate the mechanical stability limit of the solid phase.
- The constrained system exhibits a critical point and a triple point.
- Both critical and triple points occur at higher temperatures and pressures compared to the unconstrained system.
Conclusions:
- The single occupancy constraint in the Wigner-Seitz cell reduces system entropy.
- This entropy reduction leads to higher phase transition temperatures and pressures.
- The constrained cell model provides valuable insights into the behavior of condensed matter systems.
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