Simulation of the Self-Assembly of Metal Nanoclusters

• Published in: Russian metallurgy Metally Vol. 2022; no. 8; pp. 927 - 932
• Main Authors: Korenchenko, A. E., Vorontsov, A. G., Okulov, R. A., Gel’chinskii, B. R.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-08-2022; Springer Nature B.V
• Subjects: Boiling points; Chemistry and Materials Science; Clusters; Coagulation; Condensates; Conduction heating; Conductive heat transfer; Copper; Equations of motion; Low temperature; Macroscopic models; Materials Science; Metallic Materials; Molecular dynamics; Monomers; Monte Carlo simulation; Nanoclusters; Nanoparticles; Nucleation; Self-assembly; Simulation; Supersaturation; self-assembly; multiscale modeling; homogeneous nucleation; metal nanoparticles
• ISSN: 0036-0295; 1555-6255; 1531-8648
• DOI: 10.1134/S0036029522080067

The production of metal nanopowders with specified sizes requires an analysis of the relationship between the physical conditions in industrial installations and the geometric properties of nanoparticles. Predictive mathematical modeling is one of the possibilities of investigating this relationship. The use of thermodynamic nucleation models does not allow one to achieve quantitative agreement with experiment results, so the data can differ by a few orders of magnitude. The kinetic Monte Carlo methods popular in recent decades make it possible to approach the scale of a real experiment; however, they consider an initial state of a medium as ideal crystalline nuclei formed in advance and evenly distributed in space, on the surface of which adsorption and desorption processes take place, and monomers diffuse to their surface in the medium. The rates of these processes are determined by coefficients, the values of which can be chosen to best describe experimental data or calculated using MD simulation. These methods do not consider the stage of nucleation and a detailed description of nucleation; therefore, it is impossible to take into account, e.g., the appearance of stable isomeric forms, “magic” clusters, and so on. In this work, we perform a multiscale simulation of the nucleation of copper nanoparticles in a gas-phase condensation chamber. The data used for a mathematical description of the atomic level of nucleation are obtained by analyzing the results of molecular dynamics calculations of copper vapor condensation at various degrees of supersaturation. The microdescription results are used in a macroscopic model, which includes a system of equations of motion, heat conduction, and diffusion. The analysis includes a description of nucleation, unimolecular growth, and coagulation. The concentrations of clusters of various sizes are taken into account on a logarithmic scale. In areas with a temperature close to the boiling point of copper, cluster grow is found to occur mainly via the attachment of monomers; in low-temperature areas, coagulation is the predominant growth mechanism.