Temperature scaling of the homogenous vapor-to-liquid nucleation rate, J, is examined in a model Lennard-Jones (LJ) system. The model uses the Bennett Metropolis Monte Carlo technique to determine small cluster growth/decay rate constant ratios ßn-1|αn at four temperatures (T = 40, 50, 60, and 83.6K) below the argon Lennard-Jones critical temperature, Tc. The ßn-1|αn for clusters ranging in size from n = 2 to n = 192 LJ particles are applied to a kinetic steady-state nucleation rate formalism and nucleation rates are determined at the same four temperatures. When these rates are plotted first in the standard way vs. lnS, (where S is the ratio of ambient to coexistence vapor pressure) and then vs. the scaled supersaturation, lnS / [Tc/T-1]3/2, the values of logJ are found to collapse onto a single line. This demonstrates that the nucleation rate is a function of lnS / [Tc/T-1]3/2 -- rather than of the independent variables, S and T. A similar scaling has been observed in the experimental nucleation rate data of water and toluene. The present study is the first simulation based demonstration of vapor to liquid nucleation rate temperature scaling in a model dilute vapor system and provides insight into the "law of mass action" model assumptions which give rise to the scaling.
Hale, Barbara N.
Parris, Paul Ernest, 1954-
Ph. D. in Physics
Missouri University of Science and Technology
viii, 155 pages
© 2012 Mark Allan Thomaso, All rights reserved.
Dissertation - Open Access
Monte Carlo method
Electronic OCLC #
Thomason, Mark Allan, "A Monte Carlo study of the scaling of nucleation rates in a Lennard-Jones system" (2012). Doctoral Dissertations. 2025.