A hybrid sectional-moment model for coagulation and phase segregation in binary liquid nanodroplets

We describe a new formulation of the aerosol general dynamic equation (GDE) that incorporates the phase segregation in a binary aerosol. The model assumes that complete phase segregation is the thermodynamically favored state, that no thermodynamic activation energy exists, and that the segregation process is kinetically controlled. We develop a GDE formulation that involves the solution of a distribution function N_n,σ (V), where N_n,σ (V) is the number density of aerosols with volume V and n phase domains (which we might think of as enclosures) with an enclosure size distribution characterized by σ. The model improves our earlier efforts (Struchtrup H., M. Luskin & M. Zachariah, 2001. J. Aerosol Sci. 15(3)) which did not account for the enclosure size distribution. The description of the enclosures is based on a moment approach relying on a log-normal distribution (Park S., K. Lee, E. Otto & H. Fissan, 1999. J. Aerosol Sci. 30, 3-16). As with our earlier model, we obtain an increase of the mean number of enclosures per droplet in time, in disagreement to experimental results. The reasons for the disagreement are discussed.