1. Introduction to Nanoseparation

Nanomaterials have been attracted tremendous attentions for decades, due to their unique properties on nanoscale. As well known, the properties, such as chemical, thermal, mechanical, optical, electrical, and magnetic properties, are highly dependent on the size of nanomaterials, as so-called size-dependent quantum effect. Thus, to obtain monodisperse nanostructures is of great significance. With the help of various ligands, solution-phase synthesis could produce colloidal nanostructures with relatively homogeneous morphology and narrow size distribution for some nanosystems. However, owing to the synthetic difficulties, fine control of uniform nanostructures still remains a big challenge. Besides, nanoseparation, as a “post-synthesis” method, is a powerful tool to sort and achieve monodispersity and to avoid possible aggregation of the colloids. In this chapter, the basic principles of nanoseparation and a brief introduction of common techniques used for the separation of nanostructures, including membrane filtration, chromatograph, electrophoresis, magnetic field and centrifugation, will be discussed.