Remarks on the interfacial tension in colloidal systems

A scaling relation is used to estimate the interfacial tension of phase separated colloidal dispersions. Conditions are focused on where (i) the strong segregation limit applies, (ii) the interfacial structure is simple, and (iii) the phase separation is entropy driven. Comparison with experimental work on colloid-polymer mixtures, and with more elaborate theoretical work on mixtures of nonadditive hard spheres, and on coexisting isotropic and nematic phases of hard rods, shows that the scaling relation accurately captures the concentration, particle size, and interfacial width dependence of the interfacial tension.