Because the surface area of nanometer sized particles is so large, small amounts of clay additives can have an intimate relationship with the polymer, and cause significant changes in polymer behavior. Fully exfoliating a nanoclay into the host polymer is both the challenge and reward. Using organoclays prepared via an onium ion route, Toyota developed proprietary and patented technology specific to nylon, and now have other polymer systems under development. With these variables, one might suppose that there are all manner of clays formed, and that is certainly the case. Common to clays are the elements silicon and oxygen, but like organic polymers, the way they're linked together, and combined with other elements such as aluminum, magnesium, iron, sodium, potassium, make for countless iterations and matrices.
All clays are fine-grained materials and most have a phylosillicate or sheet structure.
With aspect ratios approaching 1000, surface area of the clay is in the range of 750 square meters per gram. Fortunately, Mother Nature was a somewhat sloppy chemist and isomorphous substitution by magnesium and iron is common in the octahedral aluminum layer, setting up a charge deficiency on the sheet surface. This charge is typically satisfied by sodium and calcium cations. Exchange capacities are on the order of 80 to 140 milli-equivalents per 100 grams of clay. We have developed a computational modeling capability at Nanocor, and have modeled the surface as per this illustration.