title: Adsorption into the MFI zeolite of aromatic molecule of biological relevance. Investigations by Monte Carlo simulations.
abstract: Adsorption of paracresol and water into the silicalite-1 (MFI) zeolite has been investigated using canonical and grand-canonical Monte Carlo simulations. The most stable sites of adsorption of paracresol are found to be located at the channel intersections. Grand-canonical simulations have shown that at low loading, water molecules adsorb preferably at the vicinity of paracresol molecules, whereas they are also located in the sinusoidal channels as the loading increases. In order to explain the experimental adsorption isotherm observed for the coadsorption of water and paracresol in the MFI zeolite we propose a new concept of apparent adsorption enthalpy that varies with the concentration of the solution. The mathematical expression for the apparent enthalpy is introduced in an adsorption isotherm model. We shall refer to this theoretical isotherm as a non-langmuirian isotherm. The non-linear expression for the apparent adsorption enthalpy accounts for a variable accessibility of the sites of adsorption with respect to the concentration of the solution.
authors.affiliation: Laboratoire Chimie Provence, University Aix-Marseille I, II and III, UMR-CNRS 6264, Avenue Escadrille Normandie-Niemen, F-13397 Marseille, France. pascal.boulet@univ-provence.fr
authors.forename: Pascal
authors.initials: P
authors.lastname: Boulet
authors.forename: L
authors.initials: L
authors.lastname: Narasimhan
authors.forename: David
authors.initials: D
authors.lastname: Berg'e-Lefranc
authors.forename: Bogdan
authors.initials: B
authors.lastname: Kuchta
authors.forename: Oliver
authors.initials: O
authors.lastname: Schäf
authors.forename: Renaud
authors.initials: R
authors.lastname: Denoyel
mesh_terms: D000327:Adsorption; D000465:Algorithms; D003198:Computer Simulation; D003408:Cresols / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009010:Monte Carlo Method; D013816:Thermodynamics; D014867:Water / Q000737:chemistry; D017641:Zeolites / Q000737:chemistry*
chemical_list: D003408:Cresols; D014867:Water; D017641:Zeolites; C032538:4-cresol