How nucleation affects the aggregation of nanoparticles

Using the conducting polymer, polyaniline, as a prime example, this article highlights the important role of nucleation on the aggregation of nanoparticles. We demonstrate that during synthesis, irreversible aggregation of nanoparticles can be triggered by heterogeneous nucleation on pre-formed particles. Aggregation can be prevented by mediating the nucleation behavior via experimental conditions including mechanical agitation, reaction temperature and the use of additives. These findings may provide a valuable guide in the synthesis of many other nanostructures.