Intercalation and exfoliation: A review on morphology of polymer nanocomposites reinforced by inorganic layer structures

This review aims to address the morphology issues of polymer nanocomposites based on inorganic layer structures. Depending upon the degree of dispersion of nano-sized layer structure, polymer composites can be divided into three main categories: microcomposites, intercalated nanocomposites, and exfoliated nanocomposites. The exfoliated nanocomposites can be subdivided into ordered and disordered exfoliations. An intermediate morphology between intercalation and exfoliation, known as partial exfoliation, is also commonly seen. The above differences in morphology lead to significant variations in physical and mechanical properties of polymer nanocomposites. This review uses epoxy/clay nanocomposites to illustrate the development and recent achievements in the syntheses and exfoliation of polymer nanocomposites. Herein, a recent study on an epoxy nanocomposite based on synthetic alpha-zirconium phosphate is reviewed. The potential impact of using the synthetic alpha-zirconium phosphate as a reinforcement phase to develop fundamental understanding of the physical and mechanical behavior of polymer nanocomposites is discussed.