A STOCHASTIC COMPUTER-SIMULATION OF EMULSION COALESCENCE

As simple expressions cannot completely describe the phenomena of emulsion coalescence, a recursive stochastic model was developed. The model, embodied in a computer program, considers interactions between randomly selected pairs of particles from an emulsion particle size distribution; in the absence of a calculated energy barrier coalescence is predicted and a new particle is formed. The simulations produce volume histograms which confirm the restabilization phenomena introduced in a previous paper (S. B. Hall, J. R. Duffield, and D. R. Williams, J. Colloid Interface Sci. 143, 1991), namely, that coalescence need not result in the complete separation of an emulsion into two distinct phases since particles formed by coalescence are inherently more stable than the precursor particles. The critical aggregation ionic strength derived in that paper describes only the transition point between stability and instability; only the stochastic approach determines the extent of coalescence beyond this point. The potential of this approach is illustrated with the simulation coalescence of an intravenous fat emulsion. © 1991.