Abstract: In this paper, the Lennard -Jones potential is applied
to molecules of liquid argon as well as its vapor and platinum as solid
surface in order to perform a non-equilibrium molecular dynamics
simulation to study the microscopic aspects of liquid-vapor-solid
interactions. The channel is periodic in x and y directions and along z
direction it is bounded by atomic walls. It was found that density of
the liquids near the solid walls fluctuated greatly and that the
structure was more like a solid than a liquid. This indicates that the
interactions of solid and liquid molecules are very strong. The
resultant surface tension, liquid density and vapor density are found
to be well predicted when compared with the experimental data for
argon. Liquid and vapor densities were found to depend on the cutoff
radius which induces the use of P3M (particle-particle particle-mesh)
method which was implemented for evaluation of force and surface
tension.
Abstract: In this work, we incorporated a quartic bond potential
into a coarse-grained bead-spring model to study lubricant adsorption
on a solid surface as well as depletion instability. The surface tension
density and the number density profiles were examined to verify the
solid-liquid and liquid-vapor interfaces during heat treatment. It was
found that both the liquid-vapor interfacial thickness and the
solid-vapor separation increase with the temperatureT* when T*is
below the phase transition temperature Tc
*. At high temperatures
(T*>Tc
*), the solid-vapor separation decreases gradually as the
temperature increases. In addition, we evaluated the lubricant weight
and bond loss profiles at different temperatures. It was observed that
the lubricant desorption is favored over decomposition and is the main
cause of the lubricant failure at the head disk interface in our
simulations.