Nanoclay is a surface modified montmorillonite clay, or masterbatche containing modified clay, that is utilized to make a nanocomposite.

Nanoclays are nanoparticles of layered mineral silicates. Silica is the dominant constituent of clays, with Alumina being essential, as well. Clays have a layered structure consisting of 2 types of sheets, the silica tetrahedral and alumina octahedral sheets. The silica tetrahedral sheet consists of SiO4 groups linked together to form a hexagonal network of the repeating units of composition Si4O10. The alumina sheet consists of two planes of close packed oxygen’s or hydroxyls between which octahedrally coordinated aluminum atoms are imbedded in such a position that they are equidistant from six oxygens or hydroxyls. The two tetrahedral sheets sandwich the octahedral, sharing their apex oxygens with the latter. These 3 sheets form one clay layer.
Polymer grade (PG) montmorillonites are high purity aluminosilicate minerals sometimes referred to as phyllosilicates. They are intended for use as additives to hydrophilic polymers such as polyvinylalcohols, polysaccharides and polyacrylic acids. When fully dispersed in these host polymers they create a new category of composite materials called nanocomposites.