Simultaneous application of the gradient theory and Monte Carlo molecular simulation for the investigation of methane/water interfacial properties

Christelle Miqueu (1) , Jose Manuel Miguez (2) , Manuel Pineiro (2) , Thomas Lafitte (1) , Bruno Mendiboure (1)

1 LFCR - Laboratoire des Fluides Complexes et leurs Réservoirs
2 Departamento de Física Aplicada

This work is dedicated to the simultaneous application of the gradient theory of fluid interfaces and Monte Carlo molecular simulations for the description of the interfacial behavior of the methane/water mixture. Macroscopic (interfacial tension, adsorption) and microscopic (density profiles, interfacial thickness) properties are investigated. The gradient theory is coupled in this work with the SAFT-VR Mie equation of state. The results obtained are compared with Monte Carlo simulations, where the fluid interface is explicitly considered in biphasic simulation boxes at both constant pressure and volume (NPT and NVT ensembles), using reliable united atom molecular models. On one hand, both methods provide very good estimations of the interfacial tension of this mixture over a broad range of thermodynamic conditions. On the other hand, microscopic properties computed with both gradient theory and MC simulations are in very good agreement with each other, which confirms the consistency of both approaches. Interfacial tension minima at high pressure and prewetting transitions in the vicinity of saturation conditions are also investigated.

Mots clés: Biphasic; Constant pressures; Density profile; Equation of state; Fluid interface; Gradient theory; High pressure; Interfacial behaviors; Interfacial property; Interfacial thickness; MC simulation; Microscopic properties; Molecular models; Molecular simulations; MONTE CARLO; Monte Carlo Simulation; Prewetting transitions; Saturation conditions; Simulation boxes; Thermodynamic conditions; United atoms Engineering controlled terms: Adsorption; Equations of state; Fluidity; Investments; Molecular structure; Monte Carlo methods Engineering main heading: Computer simulation

Domaines: Chimie-Physique [physics.chem-ph]

Christelle Miqueu, Jose Manuel Miguez, Manuel Pineiro, Thomas Lafitte, Bruno Mendiboure. Simultaneous application of the gradient theory and Monte Carlo molecular simulation for the investigation of methane/water interfacial properties. Journal of Physical Chemistry B, 2011, 115 (31), pp.9618-9625. ⟨10.1021/jp202276k⟩. ⟨hal-00684574⟩