Clay mineral layers and nanoparticles

This chapter provides an introduction to the properties of naturally occurring oxide ultra-thin films and nanoparticles of complex composition, namely clay minerals. Clays represent a wide family of nanomaterials, formed from the weathering of primary rocks at the Earth surface. Their layered structure is responsible for their extreme anisotropy and their extremely high specific surface area which is at the origin of their unique properties and of their strong interaction with their surrounding. The focus of this chapter is on their structural and composition characteristics, the conditions of their formation, their interaction with water and their chemical properties. A mention is given of their uses in human cultural activities, in dwelling constructions and statuary, in porcelain fabrication, in retention of metal contaminants in the environment, in the pharmaceutical and cosmetic industries, and as lubricants, catalysts, therapeuthic agents, among others.