A Semi-Empirical Analytical Model for Determining the Thermodynamic Stability of Pickering Emulsion

The prediction of thermodynamic stability of Pickering emulsion is of fundamental importance for various practical applications. Whereas massive experimental and theoretical work has been contributed for examining the stability of functional solid nanoparticles at different liquid-liquid interfaces, most of these works are very specific, and no generic model has yet been reported. Here, we first propose a semi-empirical analytical model to determine the thermodynamic stability of Pickering emulsion. This model, simply relying on the Flory-Huggins parameters of different compositions as input, is developed by evaluating the contact angle of solid nanoparticle. The determination of contact angle is associated with the liquid-liquid interfacial tension and liquid-solid surface tensions, whose analytical relations in terms of Flory-Huggins parameters and solid particle size are devised with the help of Dissipative Particle Dynamics simulations. This semi-empirical analytical model, in good agreement with experiment data, provides a straightforward route for predicting the thermodynamic stability of Pickering emulsion, as the Flory-Huggins parameters of most chemicals are available in standard manuals.