Pore Size Assuming a Geometry

There are two ways of calculating the pore size. For the first one, one needs to assume a pore geometry. For cylindrical pores, the pore radius is given by the simply derived geometrical relationship 

If slit-like pores were assumed then would become the distance between the slit walls. These are the primary types of pores other types would require other relationships. Making the appropriate substitutions into Eq. (189) and taking into account Eq. (188) the following results  

The classical thickness if obtained from the molar volume and area covered is 

This works for a flat surface however for a restricted geometry the amount adsorbed remains the same and the thickness will vary. In a cylindrical pore with a radius the amount adsorbed from the pore wall to a distance t from the wall is 

---