Nucleation by a charged particle in fluids containing salt

Abstract

We present a model to describe ion-induced nucleation in fluids. Nucleation is induced by a charged molecular aggregate, a large ion, a charged colloid, or an aerosol particle. This model generalizes the Thomson model to polar environments. Solving the Poisson-Boltzmann equation, we find the potential profiles around the charged core and calculate the energy. Our results are analytical in the Debye-Hückel limit and numerical otherwise. From the Gibbs free energy curve vs. nucleus size, we find the metastable and stable states and the energy barrier between them, for varying saturation values, core's charge, and amount of salt. The nucleation barrier decreases with increasing core charge or Debye length. We calculate the phase lines in the phase diagram of supersaturation and core charge. We find regions of one phase, electro-prewetting, spontaneous nucleation, ion-induced nucleation, and classical-like nucleation.