Observation of Single Colloidal Platinum Nanocrystal Growth Trajectories

Abstract

Mergers and Acquisitions The crystallization of small molecules or polymers is often described in terms of a nucleation stage, where initial clusters form, followed by a distinct growth stage. Growth can come from the addition of unbound molecules, or through “Ostwald ripening” where larger crystals grow at the expense of smaller ones due to thermodynamic effects. Zheng et al. (p. 1309 ) studied the growth of platinum nanocrystals inside a transmission electron microscope using a special liquid cell, allowing observation of crystal growth in situ. Both monomer addition to growing particles and the coalescence of two particles were observed. The specific growth mechanism appeared to be governed by the size of each of the particles. The combination of growth processes makes it possible for an initially broad distribution of particles to narrow into an almost uniform one.