Stimulated adsorption and capillary condensation

The joint adsorption of silver and water vapors on an ideal substrate is studied in a numerical experiment using a modified Langmuir adsorption model. The calculations reveal a number of previously unknown phenomena. It is established that the adsorption and condensation of silver vapor stimulate the adsorption of water vapor, resulting in its capillary condensation at the molecular level even at low saturation. It is shown that the rate of capillary condensation depends on the wetting angle of water on silver, and there is a characteristic wetting angle at which the rate of capillary condensation changes radically. It is also found that water vapor has a significant effect on the adsorption of silver vapor and the structure of its condensate on the substrate: the presence of water vapor reduces the adsorption of silver atoms on the substrate and weakens the adhesion of silver condensate to the substrate. The results can be used to study two-component adsorption and capillary condensation and to develop technologies for growing thin films in a gas phase.