Time Dependence of Adsorption at Solid Liquid Interfaces*
نویسنده
چکیده
In this paper the time dependence of adsorption at solid-Iiquid interface is discussed for both the mass-transport and intrinsic kinetic control of the adsorption process. It has been shown that the time dependence of adsorption of the mass-transport control' of the adsorption process is mostly dependent on the strength of adsorption (natur al diffusion) and sametimes on the mass-transport coefficient (dispersion coefficient in the case of eddies), which appear in natural environments). For the intrinsic kinetic control of adsorption several rate laws, are reviewed. Methods for the interpretation of adsorption experiments available in the literature are discussed. The possibility of distinguishing the mass-transport and kinetic control is mentioned. Simple models of a two-step adsorption process are described assuming the first step to be a very fast attachment of adsorbate from the homogeneous phase to the interface. It is concluded that for a correct interpretation of adsorption experiments the impression that adsorption is under equilibrium conditions should always be supported by the right shape of the adsorption isotherm. Otherwise additional experiments should be performed in a wider range of adsorption times.
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