Mechanisms of Diffusional Nucleation of Nanocrystals and Their Self-Assembly into Uniform Colloids

TL;DR

This paper reviews models of nanocrystal nucleation and their self-assembly into uniform colloids, emphasizing diffusional transport and the coupling of nucleation and aggregation processes to control particle size distribution.

Contribution

It introduces a coupled mathematical model of nanocrystal nucleation and colloid formation, highlighting how diffusional mechanisms influence uniform particle synthesis.

Findings

Coupled diffusion-based models explain uniform colloid size distribution.

Analysis of burst nucleation reveals key parameters for controlling nanocrystal size.

Aggregation modeling predicts colloid growth dynamics and size distribution.

Abstract

We survey our research on modeling the mechanisms of control of uniformity in growth of nanosize and colloid particles. The former are produced as nanocrystals, by burst-nucleation from solution. The latter, colloid-size particles, are formed by self-assembly (aggregation) of the nanocrystals. In the colloid particle synthesis, the two dynamical processes are coupled, and both are governed by diffusional transport of the respective building blocks (monomers). The interrelation of the two processes allows for synthesis of narrow size distribution colloid dispersions which are of importance in many applications. We first review a mathematical model of diffusive cluster growth by capture of monomer "singlets." Burst nucleation of nanoparticles in solution is then analyzed. Finally, we couple it to the secondary process of aggregation of nanoparticles to form colloids, and we discuss various aspects of the modeling of particle size distribution, as well as other features of the processes considered.