Application of Jaentti's method for the explanation of adsorption onto rough surfaces

Jaentti introduced a method to calc. the final value of the adsorbed mass already in a very early stage of adsorption measurements. His method was restricted to gravimetric measurements and to adsorptions, which satisfy the simplest mol. model. One of the advantages of his method was that when more complicated mol. models were necessary, the curve resulting from Jaentti s calcns. showed discrepancies from the curve predicted for the simple situation. We used such deviations to evaluate the parameters of the models necessary for the explanation of the measurements. One of the examples we discussed concerned the influence of the occurrence of two parallel and simultaneous adsorptions. In the present paper we discuss the application of these results to adsorption onto a surface where roughness could be expected to play a part. If we consider a rough surface as the sum of two extra surfaces we can apply Jaentti's method by using our former results of parallel adsorption. We characterize roughness by two parameters which we evaluated with Jaentti's method. We emphasize that the existence of roughness is not demonstrated by Jaentti's method, but that the method is useful for the evaluation of parameters introduced by other arguments or from other sources. [on SciFinder (R)]