Wetting transitions at the argon–solid-CO2interface: Molecular-dynamics studies

The wetting behavior of argon at the solid ${\mathrm{CO}}_2$ surface has been studied with a constant-temperature molecular-dynamics technique. In order to obtain results as accurately as possible, except from the minimum image convention, no additional cutoff of the intermolecular potential was used in the calculations that were all performed with vectorized codes on the Cyber 205 supercomputer. First, the orthobaric densities are determined consistently by simulating the free-liquid surface at three temperatures. Then the density profiles of the adsorbed gas are presented for bulk-gas densities approaching the dew density. With some caution, the results seem to confirm the existence of the thin-film to thick-film transition found by recent density-functional theories. The wetting temperature of that specific system is located to be between 0.95 and 1.00 in units of the reduced temperature.