Swelling and delamination of inorganic homoionic montmorillonite clay in water-polar organic mixed solvents.

The smectite group of clay minerals (smectites) consists of negatively charged clay layers and interlayer exchangeable cations. They are spontaneously delaminated in water to form single clay layers when the interlayer cations are small alkaline cations such as Na or Li. This phenomenon known as osmotic swelling has fundamental importance in constructing novel clay-based nanomaterials.