Modeling and analysis of the dynamic behavior of mechanisms that result inthe development of inner radial humps in the concentration of a single adsorbate in the adsorbed phase of porous adsorbent particles observed in confocal scanning laser microscopy experiments: diffusional mass transfer and adsorption in the presence of an electrical double layer

A theoretical model for adsorption of a single charged adsorbate that accou nts for the presence of an electrical double layer in the pores of adsorben t particles is constructed and solved. The dynamic behavior of the mechanis ms of the model can result in the development of inner radial humps (concen tration rings) in the concentration of a single charged analyte (adsorbate) in the adsorbed phase of porous adsorbent particles. The results of the pr esent work demonstrate the implication of the concept regarding the effect of the presence of an electrical double layer in the pores of adsorbent par ticles and the induced interactions between the electrostatic potential dis tribution and the mechanisms of mass transport of the species by diffusion, electrophoretic migration, and adsorption. Furthermore, the mechanisms of the model could explain qualitatively the development of the concentration ring (hump) observed in confocal scanning laser microscopy experiments. (C) 2001 Elsevier Science BN. All rights reserved.