Thermodynamic and kinetic consistency of calculated binary nucleation rates
- Lawrence Livermore National Lab., CA (United States)
- Worcester Polytechnic Institute, MA (United States)
To establish the accuracy and applicability of analytical expressions for the steady state rate of binary nucleation, we numerically solved the birth-death equations for the vapor-to-liquid transition. These calculations were performed using rate coefficients that are consistent with the principle of detailed balance and a new self-consistent form of the equilibrium distribution function for binary cluster concentrations. We found that the customary saddle point and growth path approximations are almost always valid and can fail only if the nucleating solution phase is significantly nonideal. For example, problems can arise when the vapor composition puts the system on the verge of partial liquid phase miscibility. When this occurs for comparable monomer impingement rates, nucleation still occurs through the saddle point, but the usual quadratic expansion for the cluster free energy is inadequate. When the two impingement rates differ significantly, however, the major particle flux may bypass the saddle point and cross a low ridge on the free energy surface. The dependence of the saddle point location on the gas phase composition is also important in initiating or terminating ridge crossing nucleation.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 249285
- Report Number(s):
- UCRL-JC-124229; CONF-960859-4; ON: DE96012218; TRN: 96:003843
- Resource Relation:
- Conference: 14. international conference on nucleation and atmospheric aerosols, Helsinki (Finland), 26-30 Aug 1996; Other Information: PBD: 2 Apr 1996
- Country of Publication:
- United States
- Language:
- English
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