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Excess-entropy-based anomalies for a waterlike fluid.
Jeffrey R Errington1, Thomas M Truskett, Jeetain Mittal
1Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, USA. jerring@buffalo.edu
The Journal of Chemical Physics
|January 4, 2007
Summary
Researchers found that excess entropy links anomalous thermodynamic and dynamic properties in a two-scale potential model, similar to water. This entropy scaling predicts unusual fluid behavior, including diffusivity and viscosity anomalies.
Area of Science:
- Thermodynamics
- Fluid Dynamics
- Statistical Mechanics
Background:
- Water exhibits unusual thermodynamic and dynamic properties at low temperatures.
- A two-scale potential model by Yan et al. (2005) mimics these anomalous water properties.
- Anomalous regions include decreasing structural order, increasing self-diffusivity, and increasing entropy with compression.
Purpose of the Study:
- To link anomalous fluid properties to excess entropy.
- To utilize entropy scaling to describe diffusivity anomalies.
- To predict conditions for anomalous viscosity and thermal conductivity.
Main Methods:
- Analysis of a spherically symmetric two-scale potential.
- Application of Rosenfeld's entropy scaling relationships (1977).
- Investigation of temperature-density phase diagrams.
Main Results:
- Excess entropy connects anomalous isothermal compression, diffusivity, and entropy changes.
- Entropy scaling successfully describes diffusivity anomalies.
- Predicted conditions for anomalous transport properties.
Conclusions:
- Excess entropy is a unifying factor for anomalous fluid behavior.
- Entropy scaling provides a predictive framework for dynamic anomalies.
- The two-scale potential serves as a valuable model for studying complex fluid phenomena.
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