Adsorption on a Surface with Varying Properties
Abstract
We propose a self-consistent model taking into account variations in adsorption properties of the adsorbent surface in the process of adsorption--desorption of molecules of gas on it. We introduce a dimensionless coupling parameter that characterizes the interaction of an adsorbed molecule with polarized medium. It is established that the system can be bistable if the coupling parameter is greater than a critical value and the concentration of gas belongs to a certain interval. We show that the adsorption isotherms obtained within the framework of the proposed model essentially differ from the Langmuir isotherms and establish that the Zeldovich hysteresis is possible. The kinetics of the surface coverage is analyzed in detail. We show that taking account of variations in adsorption properties of the surface in the process of adsorption--desorption leads to new phenomena: a "quasistationary" state in the case of the overdamped approximation and self-oscillations of the system in the general case.
Cite
@article{arxiv.0907.5569,
title = {Adsorption on a Surface with Varying Properties},
author = {A. S. Usenko},
journal= {arXiv preprint arXiv:0907.5569},
year = {2009}
}
Comments
33 pages with 11 figures, REVTeX 4; Correction in relation (9) and in the subsequent expressions connected with this quantity. These corrections do not affect the main qualitative conclusions of the paper. Addition of Application B: analysis of the kinetics of adsorption in the special case of slow and fast variables describing the system