The Adsorption Isotherm Types

In type VI, an initial adsorption step may be observed if a chemisorption occurs along with physisorption, however the chemisorption portion should be somewhat irreversible and subsequent isotherms will differ from the first measured isotherm. The units on the abscissa in these figures are arbitrary. Today they are usually in mmol g f 

The first step in analysis of the isotherm is to determine to which classification the isotherm belongs. A further recommendation is to determine the classification of the isotherm according to the standard curve representation or the / plot representation. This used to be more difficult than present since 

I This is characteristic of either a chemisorption isotherm (in which case the final upswing at high pressures may not be present) or physisorption on a materiM that has extremely fine pores (micropores) 

II This is characteristic of a material, which is not porous, or possibly macrop-orous, and has a high energy of adsorption 

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From the adsorption isotherm type I or for a complete monolayer, when the adsorbent fills all pores, forming a complete monolayer on 1 g of solid, we can calculate the surface area ... 

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