6. Intercalation of the Kaolin Minerals with Simple Molecules

In this chapter, the intercalation of a number of organic molecules in the kaolin group 1:1 clay minerals that are generally anticipated not to swell, will be described together with the effects of these molecules on the clay internal and external surfaces The reactive molecules are inserted between the successive clay layers, thereby breaking the hydrogen bonds between the hydroxyl groups of the octahedral sheet on one side and the oxygen atoms of the tetrahedral siloxane sheet on the other side. Van der Waals type forces and dipole-dipole interactions also contribute to interlayer bonding. In order for organic molecules to penetrate between the kaolinite layers, sufficient energy must be provided for these hydrogen bonding forces to be overcome. One way of understanding the intercalation process is to think of the kaolin layers as being solvated by the organic molecules. Infrared spectroscopy has regularly been used to demonstrate this solvation.