2 research outputs found
Threshold criterion for wetting at the triple point
Grand canonical simulations are used to calculate adsorption isotherms of
various classical gases on alkali metal and Mg surfaces. Ab initio adsorption
potentials and Lennard-Jones gas-gas interactions are used. Depending on the
system, the resulting behavior can be nonwetting for all temperatures studied,
complete wetting, or (in the intermediate case) exhibit a wetting transition.
An unusual variety of wetting transitions at the triple point is found in the
case of a specific adsorption potential of intermediate strength. The general
threshold for wetting near the triple point is found to be close to that
predicted with a heuristic model of Cheng et al. This same conclusion was drawn
in a recent experimental and simulation study of Ar on CO_2 by Mistura et al.
These results imply that a dimensionless wetting parameter w is useful for
predicting whether wetting behavior is present at and above the triple
temperature. The nonwetting/wetting crossover value found here is w circa 3.3.Comment: 15 pages, 8 figure