Synthesis of Monodisperse Spherical Nanocrystals

Nanoparticles, small units of matter with dimensions in the range1-100 nm, exhibit many advantageous size-dependent magnetic, electrical, chemical and optical properties, which are not observed at the micro scale or bulk. These properties are extremely sensitive to particle size, and thus the ability to produce monodisperse particles is critical. Due to its ease of use and flexibility, precipitation of nanoparticles from solution is one of the most widely used synthesis methods. The main disadvantage of this method is that the relationship between particle growth and system conditions is not fully understood. In practice, the optimal reaction conditions are usually ascertained empirically or intuitively. In this report we consider several different applied mathematical techniques to explain nanoparticle growth via the precipitation method. In particular, we describe the impact of size focussing and defocussing (or Ostwald ripening) on the evolution of the nanoparticle size distribution.