Surface-mediated attraction between colloids

TL;DR

This paper explores how surface fluctuations induce an attractive potential between colloids near a soft interface, significantly affecting particle distribution in confined colloidal systems.

Contribution

It demonstrates that surface fluctuations create a universal attractive interaction between colloids, with the interaction range governed by surface correlation length.

Findings

Particles experience a significant attractive potential near the interface.

Surface fluctuations influence local particle organization.

The attraction range is controlled by surface correlation length.

Abstract

We investigate the equilibrium properties of a colloidal solution in contact with a soft interface. As a result of symmetry breaking, surface effects are generally prevailing in confined colloidal systems. In this Letter, particular emphasis is given to surface fluctuations and their consequences on the local (re)organization of the suspension. It is shown that particles experience a significant effective interaction in the vicinity of the interface. This potential of mean force is always attractive, with range controlled by the surface correlation length. We suggest that, under some circumstances, surface-induced attraction may have a strong influence on the local particle distribution.