Large Scale Molecular Dynamics Simulations of the Nucleation Process in Supersaturated Vapor -The first direct comparison between laboratory experiments and molecular dynamics simulations-
Research Press Release | September 24, 2013
|Key Points||– Used large scale molecular dynamics simulations to make a direct comparison with nucleation laboratory experiments and successfully reproduced the experimental values for the nucleation rate.
– Successfully measured the formation energy of a critical nucleus and sticking probabilities that determine the nucleation process.
– The data acquired at various temperatures and supersaturation ratios are essential for the construction of a high-precision, universal nucleation model.
|Overview||The nucleation in supersaturated vapor is an essential process in a wide range of scientific and technological fields, but a quantitatively reliable theoretical model does not yet exist. This study used super-parallel computers to perform large-scale simulations involving up to 8×10^9 atoms of the condensation process from a vapor. As a result, the study was successful in quantitatively reproducing argon nucleation for the same supersaturation as the laboratory experiment conditions. Measurement via molecular dynamics simulations of the nano-sized critical nucleus formation energy that determines the nucleation process clearly demonstrated that the formation energy of a critical nucleus is far less than in conventional macroscopic models, which makes it possible to explain the high nucleation rate obtained in laboratory experiments. It was also confirmed that the probability that a monomer sticks to a nucleus depends greatly upon the supersaturation ratio as well as the temperature. The data acquired at various temperatures and supersaturations are expected to be of use in the construction of a high-precision, universal nucleation model.|
Hidekazu Tanaka, Associate Professor, Institute of Low Temperature Science, Hokkaido University
Kyoko Tanaka, Research Fellow, Japan Society for the Promotion of Science (JSPS)
|Publications||Journal of Chemical Physics (8.21.2013)|