Some Comments about the Standard Plot of Determining Mesoporosity

Some Comments about the Standard Plot of Determining Mesoporosity 

The most common method for determining the mesoporosity from a standard plot was presented in Chapter 3 in some detail. This will not be repeated here. 

It should be noted that the derivation in Chapter 3 assumed a 3D form for the Kelvin-Cohan equation. In other words, the meniscus that is causing 

This is only approximate since the two ts are not equal. The relationship between the two pressures may be determined using Eq. (27) in Chapter 3 since is the only parameter in common between adsorption and desorption. Even can change from adsorption to desorption for a variety of reasons. This latter fact is usually ignored. 

The use of the Kelvin-Cohan equation does not necessarily imply that a liquid film, with a sharp gas-liquid interface exists before commencement of capillary filling. It only implies, that given other alternatives, that the lowest Gibbs free energy situation is for the sudden appearance of a 2D or 3D interface. Thus, a continuous correction for the surface tension before capillary filling may not be justified if the theory does not depend upon an interface before the transition. This is the case for most conventional calculations of capillary filling and x theory is in this respect conventional. 

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