LAUSR

Abstract A theoretical analysis for the description of insoluble particles activation in the atmosphere has been performed using as framework the classical theory of heterogeneous nucleation. In the current work a model for heterogeneous nucleation for one-component and two-component gaseous systems was presented taking into account the process of surface diffusion during nucleating embryo formation. The theory predicts higher nucleation rates compared to the classical theory of heterogeneous nucleation and consequently higher probability of particle activation. The model including the effect of surface diffusion shows a qualitative agreement with experimental results of heterogeneous nucleation of water at different substrates. In addition, the process of heterogeneous nucleation of the sulphuric acid – water system on the surface of insoluble spherical aerosol particles in atmospheric conditions has been examined. Insoluble particle activation is depended on several factors such as the concentration of the participating vapours, the ambient temperature, the chemical composition and particle size. Our results show that activation of insoluble particles is an energetically favourable process under specific conditions in the atmosphere.