Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 9: POSTERS Single Molecules, Biopolymers, Membranes
CPP 9.25: Poster
Montag, 25. Februar 2008, 16:45–19:00, Poster A
Estimation of spinodals in pure fluids from interfacial properties obtained from equilibrium molecular dynamics and lattice Boltzmann simulations — Attila Imre1, Gusztav Mayer1, Gabor Házi1, Roberto Rozas2,3, and •Thomas Kraska3 — 1Simulator Development Department, KFKI Atomic Energy Research Institute — 2Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt, Linder Höhe, D-51147 Köln — 3Institut für Physikalische Chemie, Universität zu Köln, Luxemburger Str. 116, D-50939 Köln
In this work, local pressure and density profiles of a liquid film in contact with its vapor at equilibrium are calculated. Two methods are employed; molecular dynamics and lattice Boltzmann simulations. The set of local values of tangential pressure and density along a liquid-vapor interface exhibits a van der Waals-like loop. The loci of the extreme values of local tangential pressure in the interfacial profile are related to the spinodal state. The maximum and minimum values of the tangential pressure are linearly related to the vapor and liquid spinodal pressures, respectively. The coefficient of the relationship appears to be universal and of geometrical origin. Comparison of the spinodal curves obtained from equations of state shows good agreement with the simulation results. Based on this investigation a method is proposed for the estimation of the liquid spinodal from experimental data. Estimations for water and helium are presented.