Simulation Methodology for Liquid Interfaces

Most simulation techniques applied to date to liquid interfaces are based on classical molecular dynamics and Monte Carlo methods. With few exceptions (discussed below), these techniques can be used straightforwardly to simulate the neat interface between a liquid and a second phase and to investigate the thermodynamics and dynamics of solute adsorption and reaction. There are several excellent books on the fundamentals of these techniques as well as free software available on the internet. (For a library of free software, see http //www.ccp5.ac.uk/librar.shtml.) 

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The determination of the properties of the 1-g interface of a dipolar fluid has been performed for a Stockmayer system and a system of diatomic particles which, in addition to the point dipole interaction, interact by site-site LJ potentials in [202]. The estimates of the surface tension are shown to be in reasonable agreement with experimental results for 1,1-difluoroethane when state variables are reduced by the critical temperature and density. The preferential orientation of the dipoles is parallel to the interface. This work also contains methodological aspects of the simulation of thin liquid films in equilibrium with their vapour. In particular, a comparison is made between the results obtained for the true (Eq. 25) and slab-adapted Ewald potentials. The agreement between the two numerical determinations of the dipolar energy is quite satisfactory asserting the validity of the use of the 3D Ewald approach for the simulation in a slab geometry. 

The following five chapters deal with problems associated with solid phases, in some cases involving surface and interfacial problems. In Chapter 14, Steele presents a review of physical adsorption investigated by MD techniques. Jiang and Belak describe in Chapter 15 the simulated behavior of thin films confined between walls under the effect of shear. Chapter 16 contains a review by Benjamin of the MD equilibrium and non-equilibrium simulations applied to the study of chemical reactions at interfaces. Chapter 17 by Alper and Politzer presents simulations of solid copper, and methodological differences of these simulations compared to those in the liquid phase are presented. In Chapter 18 Gelten, van Santen, and Jansen discuss the application of a dynamic Monte Carlo method for the treatment of chemical reactions on surfaces with emphasis on catalysis problems. Khakhar in... 

Orientational structure at a liquid vapor-interface of diatomic interaction site fluids has been studied extensively by Gubbins and Thompson using both thermodynamic perturbation theory and molecular dynamics simulation, and by Tarazona and Navascues using perturbation theory. Chacon et al. have applied density-functional theories to these systems. The theoretical methodology and results are reviewed in a comprehensive article by Gubbins, to which the reader is directed for more complete details. 

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