Capillary models for porous media. Part 2.—Sorption desorption hysteresis in three dimensional networks

Sorption and desorption from a randomly-arranged three-dimensional network of circular cylinders is discussed. It is argued that pore size distributions can be found from sorption branches and a method is given which can be applied to N2 at 77°K in transition-sized pores. A consideration of desorption from single cylinders shows that hysteresis can be expected in isolated single open-ended pores. The presence of a network structure enhances hysteresis to an extent which depends on the amount of interconnection between the network pores. A method for estimating this quantity from desorption branches is discussed and exemplified.