Chain Order Within Each Layer

Nanoparticles exist in spherical, mbe and whisker, and plate-like shapes and at least one of the three dimensions is required to be on a nanometric scale. Nanostructures of layered clays are further categorized as intercalated, in which the polymer chains have penetrated between the clay layers in a well-ordered multilayer morphology, and exfoliated, in which the clay layers have dispersed along the matrix and have no organized slnictme [7]. Carbon nanombes also exhibit two nanostructmes single-walled nanotube and mnltiwalled nanotube, which is composed of several tubes within each other. 

Depending on the nature of the components used (layered silicate, organic cation, and polymer matrix) and the preparation method, three types of hybrid PCNs can be obtained [17]. Phase-separated microcomposites (conventional composites) are obtained when the polymer chains are unable to intercalate within the inorganic sheets clay lamellae remain stacked in structures marked as tactoids as in the pristine mineral. Otherwise, when the polymer chains penetrate in between the clay galleries, an intercalative system is obtained. In this case, the nanocomposite shows, at least in principle, a well-ordered multilayer morphology built up with alternating polymeric and clay layers. When clay platelets are randomly dispersed in the polymer matrix and the lamellae are far apart from each other, so that the periodicity of this platelet arrangement is totally lost, an exfoliated structure is achieved. 

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