Figure 7. Qualitative representation of Ostwald ripening occurring during Stage I in the case of: (a) diffusion-controlled; and (b)interface reaction-controlled (dissolution and precipitation) coarsening processes governed by Eq. (6) and (7), respectively. In (a)the diffusion through the liquid is assumed to be much slower than the dissolution/re-precipitation reactions, therefore the solute concentration close to the particle surfaces is approximated with the local solid solubility and a concentration gradient is formed. In (b), the opposite occurs, the liquid is thought to have a homogeneous concentration and the coarsening rate is controlled by the interface reactions.