TY - JOUR

T1 - Strict Limitations of the Approximation of Mean-Field Supersaturation in Kinetics of Nucleation and Wide Possibilities of the Excluded Volume Approach

AU - Kuchma, A. E.

AU - Shchekin, A. K.

N1 - Publisher Copyright: © 2022, Pleiades Publishing, Ltd.

PY - 2022/4

Y1 - 2022/4

N2 - Abstract: The traditional approach of the mean-field supersaturation to kinetic description of nucleation is based on assumptions that homogeneous nucleation of overcritical particles of a new phase in a closed system occurs uniformly over the volume of the system and is synchronous with a decrease in the mean supersaturation of the metastable phase. The approximation of the mean supersaturation field also implies that the transport of molecules of the metastable phase into the growing particles of the new phase is slow and stationary. We have found in this work that, in the diffusion regime of the particle growth, the approach of the mean-field of supersaturation at the end of the first stage of formation of overcritical droplets in a supersaturated vapor requires low volatility of the condensing liquid, and realizes in the case of the stage of nucleation of overcritical gas bubbles in a solution supersaturated with gas only at extremely low solubility of the gas in the solution. In particular, for condensation of water vapor and degassing ethanol supersaturated by gas with moderate or high solubility at atmospheric pressure, the approximation of the mean-field supersaturation cannot be strictly justified. We demonstrated here that there are no such restrictions when using the excluded volume approach in the kinetic description of the phase transition. Along with that we have shown, that the excluded volume approach describes fast self-similar diffusion growth of particles of a new phase at the nucleation stage, leading to the formation of a cellular structure at the next stage of the phase transformation, the stage of intense decrease in the supersaturation of the metastable system.

AB - Abstract: The traditional approach of the mean-field supersaturation to kinetic description of nucleation is based on assumptions that homogeneous nucleation of overcritical particles of a new phase in a closed system occurs uniformly over the volume of the system and is synchronous with a decrease in the mean supersaturation of the metastable phase. The approximation of the mean supersaturation field also implies that the transport of molecules of the metastable phase into the growing particles of the new phase is slow and stationary. We have found in this work that, in the diffusion regime of the particle growth, the approach of the mean-field of supersaturation at the end of the first stage of formation of overcritical droplets in a supersaturated vapor requires low volatility of the condensing liquid, and realizes in the case of the stage of nucleation of overcritical gas bubbles in a solution supersaturated with gas only at extremely low solubility of the gas in the solution. In particular, for condensation of water vapor and degassing ethanol supersaturated by gas with moderate or high solubility at atmospheric pressure, the approximation of the mean-field supersaturation cannot be strictly justified. We demonstrated here that there are no such restrictions when using the excluded volume approach in the kinetic description of the phase transition. Along with that we have shown, that the excluded volume approach describes fast self-similar diffusion growth of particles of a new phase at the nucleation stage, leading to the formation of a cellular structure at the next stage of the phase transformation, the stage of intense decrease in the supersaturation of the metastable system.

KW - bubbles

KW - droplets

KW - excluded volume approach

KW - kinetics

KW - mean-field supersaturation

KW - nonstationary diffusion

KW - nucleation

UR - http://www.scopus.com/inward/record.url?scp=85131015584&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/0995e68d-07a0-3927-9cda-55222a609dc1/

U2 - 10.1134/s1070363222040053

DO - 10.1134/s1070363222040053

M3 - Article

AN - SCOPUS:85131015584

VL - 92

SP - 641

EP - 649

JO - Russian Journal of General Chemistry

JF - Russian Journal of General Chemistry

SN - 1070-3632

IS - 4

ER -