Swelling Capacity of Montmorillonite in the Presence of Electrolytic Ions

The aim of this study was to investigate the effect of inorganic cations (Na+, Ca2+, Ba2+, Fe3+, Al3+) with different valence and concentration on the swelling behaviors of montmorillonite. Na-montmorillonite, obtained from China, was chosen as experimental objective. It was first characterized through the measurements of swelling capacity and zeta potential. Then, swelling properties of Na-montmorillonite influenced by cation concentration, valence, and hydration analyzed were studied. The results showed that the swelling capacity was much inhibited by cations of higher concentrations, higher valences, or weaker hydration. This work also verified the conclusion that the decreased degree of potential is more significant caused by cations of higher valence.