DISPERSION INTERACTIONS ACROSS BINARY-LIQUID MIXTURES - PROPER ACCOUNT OF STRUCTURAL EFFECTS

We have extended earlier work on the effects of solvent structure upon dispersion interactions to the case involving binary mixtures at arbitrary densities. Specifically, asymptotic expressions for the potential of mean force between a planar substrate and a molecule in a binary solution and also the interaction energy of two planar half spaces across a binary mixture are obtained. Both of these results include effects due to inhomogeneities in the intervening medium under the action of surface forces. An anomaly in a result of Deryaguin and Churaev has been traced to an invalid assumption about the additivity of molecule-substrate interaction potentials. © 1979.