title: Amino acid adsorption on zeolite beta.
abstract: A thermodynamic equilibrium model has been developed to describe amino acid adsorption on microporous materials. The model addresses electrostatic, hydrophobic and steric interactions. A procedure for fitting the model's parameters is presented and should be applicable to the majority of the common 20 amino acids. The approach is demonstrated using experimental measurements of L-phenylalanine and L-arginine on zeolite beta. Between the adsorption mechanisms of ion exchange and physisorption, the first can contribute as much as two-thirds of the phenylalanine adsorbed at saturation. For the materials tested, ion exchange is maximized when the zeolite's silicon-to-aluminum ratio is 12. When this atom ratio is raised to 100, ion exchange no longer plays a significant role, but the amount physisorbed increases by 30%.
authors.affiliation: Department of Chemical Engineering and Material Science, University of Minnesota, Minneapolis, Minnesota 55455-0132, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Krohn
authors.forename: Michael
authors.initials: M
authors.lastname: Tsapatsis
mesh_terms: D000327:Adsorption; D001120:Arginine / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D008956:Models, Chemical; D015394:Molecular Structure; D010649:Phenylalanine / Q000737:chemistry*; D016062:Porosity; D055672:Static Electricity; D013499:Surface Properties; D013816:Thermodynamics; D017641:Zeolites / Q000737:chemistry*
chemical_list: D017641:Zeolites; D010649:Phenylalanine; D001120:Arginine