On the potential of mean force of a sterically stabilized dispersion

The potential of mean force (PMF) of a colloidal dispersion under various circumstances of current interest, such as varying solvent quality, polymer coating thickness, and addition of electrostatic interaction is obtained from radial distribution functions available from the literature. They are based on an implicit solvent, molecular dynamics simulation study of a model titania dispersion that takes into account three major components to the interaction between colloidal particles, namely van der Waals attraction, repulsion between polymer coating layers, and a hard core particle repulsion. Additionally, a screened form of the electrostatic interaction was included also. It is argued that optimal conditions for dispersion stability can be derived from a comparative analysis of the PMF under the different situations under study. This thermodynamics based analysis is believed to be more accessible to specialists working on the development of improved titania formulations than that based on the more abstract, radial distribution functions.