A reexamination of the derivation of the equilibrium supersaturation curve for soluble particles

Abstract

Following the methods known from the heteromolecular homogeneous nucleation theory, a reexamination of the Köhler equation is presented. In contrast to the original Köhler's approach and the later reexamination of Young and Warren, activity coefficients dependent on the droplet composition and the Gibbs-Duhem relation are taken into account. The results conform with the heteromolecular homogeneous nucleation theory and show that the additional terms derived by Young and Warren completely compensate each other. The nonideal corrections for the classical Köhler equation are investigated for an H2SO4-H2O system. An increase of critical supersaturation by up to about 25% must be expected if nonideality is taken into account.