Surface Area and Its Effect on Exchange Capacity of Montmorillonite*

A bstract The particle size and exchange capacity of several samples of montmorillonite were measured. It is shown that the particle size does influence the exchange capacity. Based on recent observations of thickness of particles, the surface area can be calculated more precisely; this in turn can be related to the exchange capacity. This relationship and that existing for kaolinite are compared. It is shown that the exchange capacity is directly related to the broken Si—O, Al—O, or Al—OH linkages.