Sorption hysteresis on microrough surfaces

Numerical experiments on the adsorption of water vapor based on vapor silver substrates with different microroughness were performed using a modified Langmuir adsorption model. The calculations revealed a number of phenomena making it possible to clarify the interpretation of many experimental data on sorption. It is established that significant initial microroughness of a silver substrate causes a sharp increase in the number of molecules of an equilibrium adsorbate and provides a stable liquid film of the adsorbate under conditions close to saturation conditions. It is shown that stability of the film state is due to the fact that its further growth or evaporation are only possible because of nucleation processes under significant supersaturation or overheating. The results obtained can be used to improve technologies based on adsorption processes.