Kinetics of rapid growth and melting of AlNialloying crystals: phase field theoryatomistic simulations revisited.

A revised study of the growth and melting of crystals in congruently melting AlNialloy is carried out by molecular dynamics (MDs) and phase field (PF) methods. An embedded atom method (EAM) potential of Purja Pun and Mishin (200989 3245) is used to estimate the material's properties (density, enthalpy, and self-diffusion) of the B2 crystalline and liquid phases of the alloy. Using the same EAM potential, the melting temperature, density, and diffusion coefficient become well comparable with experimental data in contrast with previous works where other potentials were used.

Species Surface Distribution and Surface Tension of Aqueous Solutions of MIBC and NaCl Using Molecular Dynamics Simulations.

Methyl isobutyl carbinol (MIBC) is a high-performance surfactant with unusual interfacial properties much appreciated in industrial applications, particularly in mineral flotation. In this study, the structure of air-liquid interfaces of aqueous solutions of MIBC-NaCl is determined by using molecular dynamics simulations employing polarizable and nonpolarizable force fields. Density profiles at the interfaces and surface tension for a wide range of MIBC concentrations reveal the key role of polarizability in determining the surface solvation of Cl ions and the expulsion of non-polarizable Na ions from the interface to the liquid bulk, in agreement with spectroscopic experiments.

Force exerted by a nanoscale capillary water bridge between two planar substrates.

Molecular dynamics simulation of a nanoscale capillary water bridge between two planar substrates is used to determine the resulting force between the substrates without arbitrariness regarding geometry and location of the free surface of the bridge. The substrates are moderately hydrophilic. The force changes continuously as the separation between the substrates changes except for small gaps where it becomes discontinuous because the bridge is unable to adopt stable configurations at any distance apart.

Effect of Hydrodynamic Interactions on Self-Diffusion of Quasi-Two-Dimensional Colloidal Hard Spheres.

We compare experimental results from a quasi-two-dimensional colloidal hard sphere fluid to a Monte Carlo simulation of hard disks with small particle displacements. The experimental short-time self-diffusion coefficient D(S) scaled by the diffusion coefficient at infinite dilution, D(0), strongly depends on the area fraction, pointing to significant hydrodynamic interactions at short times in the experiment, which are absent in the simulation. In contrast, the area fraction dependence of the experimental long-time self-diffusion coefficient D(L)/D(0) is in quantitative agreement with D(L)/D(0) obtained from the simulation.

A molecular dynamics study of the force between planar substrates due to capillary bridges.

Molecular dynamics simulations are used to study capillary liquid bridges between two planar substrates and the origin, strength and range of the resulting force between them. Pairwise interactions are described by the Lennard-Jones potential. Surface wettability is tuned by varying the fluid-substrate well depth interaction parameter.