Simulations of interfacial

M. R. Philpott, J. N. Glosli. Molecular dynamics simulation of interfacial electrochemical processes electric double layer screening. In G. Jerkiewicz, M. P. Soriaga, K. Uosaki, A. Wieckowski, eds. Solid Liquid Electrochemical Interfaces, Vol. 656 of ACS Symposium Series. Washington ACS, 1997, Chap. 2, pp. 13-30. 

P. Ahlstrom, O. Teleman, and B. Jonsson, Molecular dynamics simulation of interfacial... 

Molecular predictions of the properties of interfacial systems are now becoming possible as a result of rapid advances in liquid state chemical physics and computer technology. The objectives of this paper are 1) to review the general approaches and models used in Monte Carlo (MC) and molecular dynamics (MD) simulations of interfacial systems, 2) to describe and discuss results from selected simulation studies of interfacial water, and 3) to discuss the major limitations of these techniques and to offer suggestions for overcoming them. 

The results in Table V illustrate that MD studies, compared to the MC results in Table IV, facilitate the investigation of transport and time-dependent properties. Also, they show that use of the MCY potential leads to very large density oscillations and increasing water density near the surfaces. This appears to be a serious drawback to the use of the MCY potential in simulations of interfacial water. Results from the investigations using the ST2 potential show that interfacial water density is approximately 1.0 g/cc, with a tendency for decreased density and hydrogen bonding near the surfaces. As in the MC simulations, orientations of the water dipole moment are affected by the presence of a solid/liquid interface, and an... 

On the whole, the advantages and strengths of MC and MD simulations of interfacial water outweigh their disadvantages and weaknesses. Even if quantitative prediction of interfacial water properties is not possible in some cases, a knowledge of qualitative trends as a function of distance from the surfaces or relative to results from simulations of bulk water are often extremely i11uminating. 

A related, relatively unexplored topic is the importance of many-body forces in the simulations of interfacial systems. The development of water-polarizable models has reached some level of maturity, but one needs to explore how these models must be modified to take into account the interactions with the metal surface atoms and the polarizable nature of the metal itself... 

J. W. Halley and J. Hautmann, Phys. Rev. B 38 11704 (1988). First molecular dynamic simulation of interfacial electron transfer. 

Wijmans, C.M., Dickinson, E. (1998). Simulation of interfacial shear and dilatational rheology of an adsorbed protein monolayer modeled as a network of spherical particles. Langmuir, 14, 7278-7286. 

Simon R. Phillpot, Paul D. Bristowe, and David G. Stroud, Microscopic Simulation of Interfacial Phenomena in Solids and Liquids. Proceedings of a symposium held 1-4 December 1997, in Boston, Massachusetts, in Mater. Res. Soc. Symp. Proc., Vol. 492, Materials Research Society, Warrendale, PA, 1998. 

Rego LGC, Batista VS. Quantum dynamics simulations of interfacial electron transfer in sensitized Ti02 semiconductors. J Am Chem Soc 2003 125 7989-97. 

Chang, R.-F.C., Skipper, N.T., and Sposito, G., Monte Carlo and molecular dynamics simulations of interfacial structure in hthium-montmorillonite hydrates., Langmuir, 13, 2074, 1997. 

As discussed earlier, coalescence break-up models incorporated in detailed CFD models will allow accurate simulation of interfacial area and corresponding mass and... 

Wong, K.Y. and Pettitt, B.M. A new boundary condition for computer simulations of interfacial systems. Chemical Physics letters, 2000, 326 (3-4), p. 193-198. 

Pugnaloni, L.A., Ettelaie, R., and Dickinson, E. Computer simulation of interfacial structure and large-deformation rheology during competitive adsorption of proteins and surfactants. Food Colloids Interactions, Microstructure and Processing, E. Dickinson, ed.. Royal Society of Chemistry, Cambridge, U.K., 2005a, p. 131. 

After the static test mentioned above, the method is now tested for the impact and spreading of a glycerin droplet on a wax substrate and the computational results are compared with the experimental data of Sikalo et al. [32], The details of the experimental setup, material properties and computational model can be found in Refs. [33, 51]. The computed and experimental spread factor and contact line are plotted in Figs. 19a and b, respectively. These figures show that the present front-tracking method is a viable tool for simulation of interfacial flows involving moving contact lines. 

P. Ahlstrom, O. Teleman, and B. jonsson,/. Am. Chem. Soc., 110, 4198 (1988). Molecular Dynamics Simulation of Interfacial Water Structure and Dynamics in a Paravalbumin Solution. 

Abstract Among the noncontinuum-based computational techniques, the lattice Boltzman method (LBM) has received considerable attention recently. In this chapter, we will briefly present the main elements of the LBM, which has evolved as a minimal kinetic method for fluid dynamics, focusing in particular, on multiphase flow modeling. We will then discuss some of its recent developments based on the multiple-relaxation-time formulation and consistent discretizatirai strategies for enhanced numerical stability, high viscosity contrasts, and density ratios for simulation of interfacial instabilities and multiphase flow problems. As examples, numerical investigations of drop collisions, jet break-up, and drop impact on walls will be presented. We will also outline some future directions for further development of the LBM for applications related to interfacial instabilities and sprays. 

Periodic Boundary Conditions. - Computer simulations of interfacial systems have traditionally employed 2D periodicity and implemented a single layer embedded within a vacuum, or, with 3D periodicity, a lamellar structure. Wong and Pettitt devised a new boundary condition which contains only one interface, using an asymmetric unit of space group Pb. The lower half of the simulation cell is obtained by applying to the asymmetric unit a combination of reflection and translation operations across the intervening surface boundary plane. ... 

The approach taken in the research described here is characterized by a very simple model construction phase, followed by an extensive series of tests involving information from ab initio electronic structure theory, mineralogy, aqueous chemistry, and high vacuum surface science. As of the time of this review, classical models are the only models simple enough to perform the necessary benchmarking calculations in all these areas and also are the only models that can be extended to 10,000 atom/nanosecond timescale simulations of interfacial phenomena. 

Ba egyi, G. (1984) Computer simulation of interfacial pwlarization in stratified dielectric systems, II. Bilayer dielectric, temperature domain. Colloid Polymer Sci., 262, 967-977. 

H. Watarai, M. Gotoh, and N. Gotoh, Interfacial mechanism in the extraction kinetics of Ni(II) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol and molecular dynamics simulation of interfacial reactivity of the ligand, Bull. Chem. Soc. Jpn., 70, 957-964 (1997). 

H. Watarai and Y. Onoe, Molecular dynamics simulation of interfacial adsorption of 2-hydroxy oxime at heptane/water interface, Solv. Extr. Ion Exch., 19(1), 155-166 (2001). 

Molecular Dynamics Simulation of Interfacial Electrochemical Processes Electric Double Layer Screening... 

The status of computer simulations of electric double layers is briefly summarized and a road map for solving the important problems in the atomic scale simulation of interfacial electrochemical processes is proposed. As examples efforts to simulate screening in electric double layers are described. Molecular dynamics simulations on systems about 4 nm thick, containing up to 1600 water molecules and NaQ at IM to 3M concentration, displayed the main features of double layers at charged metal surfaces including bulk electrolyte zone, diffuse ionic layer that screens the charge on the electrode and a layer of oriented water next to the surface. 

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