Adsorption and desorption surface dynamics of gaseous adsorbate on silicate-1 by molecular dynamics simulation

The dynamics of adsorption and desorption of gaseous molecules on the external surface of a crystal and a membrane of zeolite silicate-1 is investigated by molecular dynamics simulation. The gases are argon and three hydrocarbons, n-heptane, n-butane and ethylene. The sticking coefficient and the desorption coefficient are calculated for different coverages. The results clearly show that the desorption coefficients increase with the coverage contrary to the sticking coefficients. To have a better insight in the process, the desorption and adsorption time are computed, they are very similar and they show an increase with the coverage except for n-heptane which exhibit a specific decreasing behaviour at high loading.