Can one imagine the utility of a dispersed-phase reinforcement for polymers that has a thickness of 1 nm, a platelike morphology with minimal dimensions of 150 to 200 nm, robust with a modulus of 180 GPa, nontoxic (FDA classification of GRAS; generally regarded as safe for a majority of applications), a surface area in excess of 750 m2/g, a charge suitable for altering its hydrophobic–hydrophilic balance at will, and a refractive index similar to polymer so that the nanoparticles will appear transparent in the polymer composite? How difficult would it be to prepare such a particle?

This particle is naturally occurring and found around the world. It is easily mined and purified. The reactor for the particle was a volcano. The ash from many volcanoes was spread around the earth during an intense period of activity many millions of years ago. This ash was transformed into clay (montmorillonoids or smectites) by natural processes, into uncharged species (talc and pyrophyllite) and charged species through isomorphic substitution of the crystal structure (hectorite, montmorillonite, saponite, suconite, volchonskoite, vermiculite, and nontronite).

Montmorillonite serves as the principle mineral for the development of polymer–clay nanocomposites discussed in this book. A misunderstanding of the terms bentonite (the ore or rock) and montmorillonite (the mineral) are pervasive in the literature. We will focus on utilizing the mineral name. The composition of montmorillonite can be described by imagining a sandwich structure with the top and bottom layers composed of silica dioxide tetrahedral structures.