Abstract
A formalism for the adsorption kinetics of systems where the desorption rate is a function of the residence time of the adsorbed particle is presented. The adsorbed density at time t is expressed simply as a convolution of a memory kernel, Q(t), and the available surface function, φ(t). For completely irreversible adsorption, Q(t) = 1, while for a system which approaches an equilibrium state, Q tends to zero at sufficiently large times. When the desorption rate, k d , is constant, Q(t) = exp(−k d t). Two models for the memory kernel are considered. In the first, the molecule is assumed to interact with the surface via two ligands which bind and debind at rates λ and µ respectively. In the second model, the adsorption is assumed to be partially reversible: molecules transform to a permanently bound state at a rate λ and desorb at a rate µ. In both models, the adsorption kinetics and memory kernels are found analytically. Strategies for determining the memory function from experimental data are discussed.
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Talbot, J. Time dependent desorption: A memory function approach. Adsorption 2, 89–94 (1996). https://doi.org/10.1007/BF00127102
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DOI: https://doi.org/10.1007/BF00127102