Indirect interaction of colloidal molecules adsorbed on soft surfaces

Abstract

Colloidal molecules adsorbed on Langmuir–Blodgett films interact ia elastic substrate deformations. The interaction potential of this indirect force depends on the alteration of the surface profile around the adsorbed molecules. If an adsorbed particle causes a reduction of the substrate thickness, an attraction force results. Otherwise, if the adsorbate only bends the surface profile without changing the average film thickness, adsorbed molecules repel each other. The strength of this repulsion force decreases with increasing thickness of the Langmuir–Blodgett film. Colloidal molecules incommensurately adsorbed on the surface of soft crystals behave differently. For large distances their interaction is always attractive.