Revised classical binary nucleation theory for aqueous alcohol and acetone vapors

Abstract

A revised classical theory of binary nucleation is used to calculate conditions for the onset of nucleation in aqueous methanol, ethanol, 1-propanol, and acetone mixtures. The theory implicitly accounts for surface enrichment of clusters through the use of the Gibbs adsorption equation and uses only bulk thermodynamic properties. Very good agreement with diffusion cloud chamber results is found for all four systems, demonstrating the adequacy of using the bulk surface tension to predict nucleation onset at low nucleation rates. Calculated onset of ethanol/water nucleation at higher rates also agrees acceptably with shock tube data. Unphysical behavior is calculated at very high nucleation rates and/or for very nonideal mixtures, limiting the range of applicability of the theory.