A Kinetic Model for Nanocrystal Morphology Evolution

Abstract

A kinetic model is developed with the goal of understanding and predicting the morphology evolution of nanocrystals in nonequilibrium growth conditions. The model is based on the assumption that under such conditions, different crystal planes have different kinetic parameters. This model focuses on the morphology-developing stage and is successfully related to the nucleation process and other crystal evolution mechanisms. It is believed to be a universal model and is applied to discuss the morphology evolution of CdSe nanocrystals, including the aspect ratio, injection schemes, ligands effect and morphology distribution.

Experimental and theoretical approach of nanocrystalline TiO2 with antifungal activity

“…In this nonclassical crystallization process, the crystal formation, which is controlled by a monomer-by-monomer assembly, is replaced by a process involving the spontaneous self-organization of adjacent nanocrystals to share a common crystallographic orientation and coalescence; i.e., by the OA growth mechanism [37]. A kinetic model to describe the OA growth process of nanoparticles in colloidal suspensions was proposed [38] and other studies based on this mechanism were developed by Penn [39] and Xu et al [40].…”

Monodisperse BaF2 Nanocrystals: Phases, Size Transitions, and Self‐Assembly

“…In this process, the diffusion of methanol, a commonly used "nonsolvent" for precipitating nanocrystals, will disturb the system of oleic acid capped nanocrystals in cyclohexane. According to Wei and co-workers, [7] the reaction rates of BaF 2 monomers in our experiments are given by Equations (1a,b) Through this approach highly ordered self-assembly nanocrystals were formed at the interface of cyclohexane and the mixture.…”

“…Ideal individual nanocrystals are also required as building blocks for highly ordered superstructures. [7] Cubic-phase CaF 2 nanoparticles have been prepared by a hydrothermal approach without any surfactant. [5] We believed BaF 2 nanocrystals to be a good model for investigation of the phase transition by thermodynamics [6] and the size transition by kinetics.…”

Monodisperse BaF2 Nanocrystals: Phases, Size Transitions, and Self‐Assembly

“…[5] We believed BaF 2 nanocrystals to be a good model for investigation of the phase transition by thermodynamics [6] and the size transition by kinetics. [7] Cubic-phase CaF 2 nanoparticles have been prepared by a hydrothermal approach without any surfactant. [8] Cubicphase BaF 2 nanorods could be synthesized with the help of cetyltrimethylammonium bromide surfactant, which forms reverse micelles during the reaction.…”

“…Since the above growth process took place under nonequilibrium conditions, we applied a diffusion-controlled kinetic (DCK) model to explore the morphology evolution of both cubic-and orthorhombic-phase BaF 2 nanocrystals qualitatively. According to Wei and co-workers, [7] the reaction rates of BaF 2 monomers in our experiments are given by Equations (1a,b)…”