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]. This allows us to describe solution structure (distribution functions, density profiles) not only in coexisting liquid phases, but also at the interface. Importantly this builds a connection of solution structure to macroscopic thermodynamic and transport properties (surface tension, Henry constant, partial molar volumes, diffusion coefficients, etc.).
We will illustrate this framework on MD simulation data of liquid-gas equilibrium of p-xylene and (supercritical) methane at a series of temperatures, presenting effects of dissolved gas on surface tension and solution structure of coexisting phases.
Utilizing united-atom TraPPE force-field[3], this approach provides quantitative description of studied thermodynamic and transport properties as well as a novel atomic-level insight into industrially relevant systems. [4,5].
Authors acknowledge the financial support obtained from Czech Science Foundation (GACR) and Swiss National Science Foundation (SNSF) within the research project 23 04741K, and from the Ministry of Education, Youth and Sports of the Czech Republic within the specific university research grant A1_FCHI_2024_001, and through the e-INFRA CZ (ID:90254) within project OPEN-30-6.
References:
[1] Abraham, M. J.; Murtola, T.; Schulz, R.; Páll, S.; Smith, J. C.; Hess, B.; Lindahl, E. GROMACS: High Performance Molecular Simulations through Multi-Level Parallelism from Laptops to Supercomputers. SoftwareX 2015, 1-2, 19–25. https://doi.org/10.1016/j.softx.2015.06.001.
[2] Feng, C. Q.; Smith, P. E. Theory and Computer Simulation of Solute Effects on the Surface Tension of Liquids. Journal of Physical Chemistry B 2008, 112 (30), 8975–8984. https://doi.org/10.1021/jp711062a.
[3] Transferable Potentials for Phase Equilibria. 4. United-Atom Description of Linear and Branched Alkenes and Alkylbenzenes, The Journal of Physical Chemistry B, 2000 104 (33), 8008-8016, DOI: 10.1021/jp001044x
[4] Ondřej Vopička; Petr Číhal; Klepić, M.; Crha, J.; Hynek, V.; Karel Trtík; Boillat, P.; Pavel Trtik. One-Pot Neutron Imaging of Surface Phenomena, Swelling and Diffusion during Methane Absorption in Ethanol and N-Decane under High Pressure. PLOS ONE 2020, 15 (9), e0238470–e0238470. https://doi.org/10.1371/journal.pone.0238470.
[5] Ondřej Vopička; Tereza-Markéta Durďáková; Petr Číhal; Boillat, P.; Pavel Trtik. Absorption of Pressurized Methane in Normal and Supercooled P-Xylene Revealed via High-Resolution Neutron Imaging. Scientific Reports 2023, 13 (1). https://doi.org/10.1038/s41598-022-27142-6.
