A Microscopic Theory for the Prediction of Vapor Condensation

Abstract

Abraham has recently proposed an empirically determined surface‐energy correction to the critical size droplet obtained by fitting Band's equation of state for the saturated vapor to the experimentally measured compressibility factor. He has shown good agreement between his E(d) theory and experiment. In this paper, we present a complete development of this method based on Wergeland's ``gas'' model of a cluster. We never have to introduce the capillarity approximation, in which macroscopic thermodynamic properties of the bulk liquid phase are ascribed to a small cluster. The success of the theory is demonstrated by predicting the critical supersaturation for water vapor and ammonia for a range of temperatures. Finally, the empirically determined intensive parameters of clusters are compared with the capillarity approximation.