Theory of size-selective precipitation

A theory of size-selective precipitation of spherical nanoparticles is presented. The precipitate is assumed to be a random loose packing of spheres with low polydispersity (less than approximate to 30%). The interparticle interaction is treated in the Derjaguin approximation. The theory is used to calculate the polydispersity in the fractionated particle samples for various problem parameters. Our calculations show that, for typical particle concentrations, fractionation is effective for polydispersities above 5%.