Role of interfacial surface area on the physical phenomena of nanocomposites

Improvement in the material properties of nanocomposite materials is often stated to be because of the interfacial surface area (ISA) or inter-filler distance (IFD). Several models were suggested for understanding the material properties of nanocomposites. The occurrence of a thin surface layer surrounding nanoparticles, where the material properties would be different from the filler and filled material, has been proposed earlier. In the absence of a commercial technology to obtain the ideal placement of nanoparticles at specified locations in the material matrix, the particle dispersion is driven by practical limitations. If the surface layer and IFD are the criteria for goodness of performance, ideally, both of these should tend towards improvements with increase in filler content. However, experimental evidence suggests the saturation of material properties with filler content. This saturation needs to be fully understood in order to optimise filler content. In this reported work, the effect of filler content on inter-particle distance and ISA in nanocomposites has been investigated. The reason for the observed saturation in material properties with filler content is explained. It is mathematically shown that the ISA also shows similar characteristics as a physical phenomenon supporting the role of the ISA in the material properties of nanocomposites.