Nanocomposites have been introduced as organized and engineering structures with high-performance and unique physical and chemical properties. Polymer-based nanocomposites, containing different nanoparticles and polymers, have been extensively considered in various industries especially for medical, energy, and environmental applications. The physical, chemical and mechanical properties of nanocomposites are extremely related to the particle size, size distribution and also homogeneity of the fillers. Obviously, these characteristics of the nanocomposites are straightly depending on preparation methods. Based on the literature survey, various chemical methods are used to prepare nanocomposite materials. The chemical preparation methods include sol–gel, in-situ polymerization, intercalation, exfoliation, solution mixing process, melt mixing process, microemulsion, and so on. As an interesting research field, that is our favorite, for the first time the use of microemulsion method for synthesis of polymer-based nanocomposites by microemulsion systems have been reviewed. Moreover, recently some ionic liquid-based microemulsion systems have been introduced as a new microemulsion route for nanocomposites preparation. The microemulsion method as a novel route is believed to have potential for obtaining monodisperse and homogeneous engineering nanocomposites
