Polymer/silica nanocomposites: Preparation, characterization, properties, and applications

Currently, an increasing amount of work is being published on polymer/silica nanocomposites. The recent developments on the preparation, characterization, properties, and applications of this type of nanocomposite have been reviewed. Principally, three methods for the preparation of polymer/silica nanocomposites can be used, blending, the sol-gel process, and in situ polymerization. All the three methods have been investigated extensively. Moreover, colloidal polymer/silica nanocomposites, which represent a new category of polymer/silica nanocomposites, have attracted growing interest in recent years. Apart from the properties of individual components in a nanocomposite, the degree of dipersion of nanoparticles in the polymer and the interfacial interaction play important roles in enhancing of limiting the overall properties of the system. Some trends are observed but no universal patterns for the behavior of polymer nanocomposites can be deduced in general. The properties of polymer/silica nanocomposites, however, are generally superior to the pure polymer matrix and polymer microcomposites. In particular, they commonly exhibit improved mechanical properties and thermal stability regardless of the preparative method. "It's all interface" refers to the large volume fraction of interfacial polymer compared with the volume fraction of filler. By taking advantage of this large interfacial area and interfacial volume, unique combinations of properties of polymer nanocomposite can be achieved. Although much work has already been done on various aspects of polymer/silica nanocomposites, more research is required in order to further understand the complex structure-property relationships. Tailoring the interfacial interaction of filler/matrix is conducive to a better understanding of the relationships. © 2008 American Chemical Society.