New insight in adsorption of pyridine on the two modified adsorbents types MN200 and MN500 by means of grand canonical ensemble

To better understand the adsorption process of pyridine on modified Macronet based adsorbent types MN200 and MN500 were constructed at identical conditions (298, 308, 318 and 328 K) in single adsorption systems. The statistical physic based on the double layer model with two energies has been developed and selected. From theoretical observations and based on the simulation results, the study of the number of molecules per site indicated that the adsorbed molecules aggregate during the adsorption process for the first system (Pyridine/MN200). On the other hand, for the second system (Pyridine/MN500), we can see that the number of molecules per site increase with temperature, which is due to the presence of sulfonic acid functional groups. So because of him the process of aggregation is blocked. Energetically, the interactions between the adsorbed molecules and adsorbent surface were governed by the adsorption energy showing that a physisorption process has occurred. The two adsorption systems were characterized by probable mechanisms describing the interaction, during the adsorption process, between pyridine and the two adsorbents surface MN200 and MN500, in agreement with the statistical physics parameters. Then, the model is applied to calculate thermodynamic functions which govern the adsorption mechanisms such as entropy, free enthalpy of Gibbs and internal energy. These thermodynamics potentials functions are calculated and interpreted. (C) 2018 Elsevier B.V. All rights reserved.