Solvent structure in particle interactions. Part 2.—Forces at short range

Abstract

At small separations, less than 5–10 molecular diameters, standard theories of dispersion interactions between particles immersed in a liquid break down. The Lifshitz theory is valid only asymptotically and must be replaced by a more general theory which takes into account liquid structure near interfaces. The nature of structural forces is explored for a model system comprising two attractive half-spaces separated by a thin liquid film [Lennard-Jones fluid]. An exponentially decaying attractive potential is found, in agreement with earlier predictions based on mean field theories.