Molecular simulations of water and paracresol in MFI zeolite--a Monte Carlo study.
Paracresol is a protein-bound toxin that is not efficiently eliminated by the hemodialysis method. Monte Carlo simulations in grand-canonical (GCMC) and canonical ensembles were performed to investigate the adsorption of paracresol and water in silicalite-1 zeolite. GCMC simulations using a configurational-biased algorithm show that four paracresol molecules are adsorbed at the channel intersections per unit cell of silicalite-1. The adsorption isotherms of water with and without the presence of paracresol at the intersections were investigated. A cooperative phenomenon in the process of coadsorption has been observed: at very low chemical potential, paracresol facilitates the penetration of water into silicalite-1. This mechanism is interpreted in terms of the properties of the zeolite and paracresol molecules. A thermodynamic cycle is used to calculate the adsorption energy of paracresol in silicalite-1. The calculated adsorption energy reasonably agrees with the experimental data.
Narasimhan
L
L
Laboratoire Chimie Provence, University of Provence Aix-Marseille I, II and III and UMR-CNRS 6264, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France.
Boulet
Pascal
P
Kuchta
Bogdan
B
Schaef
Oliver
O
Denoyel
Renaud
R
Brunet
Philippe
P
D000327:Adsorption; D003408:Cresols / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D009010:Monte Carlo Method; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*; D017641:Zeolites / Q000737:chemistry*
D003408:Cresols; D014867:Water; D017641:Zeolites; C032538:4-cresol