Enhanced Saturation Coverages in Adsorption-Desorption Processes

Paul R. Van Tassel; Pascal Viot; Gilles Tarjus; Jeremy J. Ramsden; Julian Talbot

doi:10.1063/1.480715

paper

Enhanced Saturation Coverages in Adsorption-Desorption Processes

arXiv:cond-mat/9906429 · doi:10.1063/1.480715

Abstract

Many experimental studies of protein deposition on solid surfaces involve alternating adsorption/desorption steps. In this paper, we investigate the effect of a desorption step (separating two adsorption steps) on the kinetics, the adsorbed-layer structure, and the saturation density. Our theoretical approach involves a density expansion of the pair distribution function and an application of an interpolation formula to estimate the saturation density as a function of the density at which the desorption process commences, $I ¨ _{1}$ , and the density of the depleted configuration, $I ¨ _{2}$ . The theory predicts an enhancement of the saturation density compared with that of a simple, uninterrupted RSA process and a maximum in the saturation density when $I ¨ _{2} = 2/3 I ¨ _{1}$ . The theoretical results are in qualitative and in semi-quantitative agreement with the results of numerical simulations.

11 pages, 5 figures, Submitted to J. Chem. Phys