Modelling the adsorption on oxidized carbon nanotubes using a statistical mechanics approach

Carbon nanotubes have several applications including the removal of pollutants via adsorption. Many studies were carried out in order to evaluate how the functionalization of these materials improves the efficiency of the process. However, a better understanding of the mechanisms involved in adsorption on nanotubes is still needed. In this work it was evaluated how the oxidation of nanotubes influences the adsorption of a model molecule (methylene blue). For this purpose, a realistic model described on the grand canonical ensemble was used. In this approach, the experimental isotherms were adjusted and provided relevant information about the process, such as the number of layers and the orientation of the adsorbed molecules. In addition, since the treatment is based on statistical mechanics, it was possible to calculate the configurational entropy and Gibbs free energy of the process.