Speaker
Description
In this contribution we present theoretical framework for quantitative modeling of surface tension of liquids and their mixtures under high pressures. We perform molecular dynamics (MD) simulations (in GROMACS [1]) and apply statistical thermodynamics of solutions (namely Kirkwood-Buff theory) [2,3]. This allows us to describe solution structure (distribution functions) not only in coexisting liquid phases, but also at the interface, and importantly build its connection to macroscopic thermodynamics (surface tension, chemical potential, etc.).
We will illustrate this framework on MD simulation data of liquid-gas equilibrium of pure methane at a series of subcritical temperatures, presenting surface tension, vapor pressure, and solution structure of coexisting phases.
This methodology is general with respect to number and complexity of components. Thus, once calibrated to experimental data, it will provide atomic insight in novel, industrially relevant, systems studied within the joint GACR-SNSF project "Properties of liquids exposed to pressurized methane, ethane and hydrogen"
Authors acknowledge the financial support obtained from Czech Science Foundation (GACR) and Swiss National Science Foundation (SNSF) within the research project 23-04741K.
References:
[1] Abraham, M. J., Murtola, T., Schulz, R., Páll, S., Smith, J. C., Hess, B., & Lindah, E. (2015). Gromacs: High performance molecular simulations through multi-level parallelism from laptops to supercomputers. SoftwareX, 1–2, 19–25.
[2] Smith, P. E., Matteoli, Enrico., & O’Connell, J. P. (2013). Fluctuation Theory of Solutions : Applications in Chemistry, Chemical Engineering, and Biophysics. CRC Press.
[3] Chen, F., & Smith, P. E. (2008). Theory and Computer Simulation of Solute Effects on the Surface Tension of Liquids. The Journal of Physical Chemistry B, 112(30), 8975–8984.