Mechanism of adsorption of p-cresol uremic toxin into faujasite zeolites in presence of water and sodium cations – A Monte Carlo study

Abstract Atomistic Monte Carlo simulations on the adsorption of p -cresol and water in faujasite zeolites have been performed. Two types of zeolites were used, namely a hypothetical, pure silica faujasite and the NaY one. The comparison of the results obtained for both zeolites on the adsorption of p -cresol shows that the molecules are mainly adsorbed at the supercage and few of them are located at the cage windows. The presence of the sodium cations in the framework of NaY does not modify substantially the qualitative observations made for pure-silica faujasite. By contrast, the presence of the cations modifies notably the shape of the adsorption isotherm of water (either in presence or absence of p -cresol molecules in the zeolite pores) which can be correlated with the energetics of interaction between the species in the system.