Capillary-induced interactions between colloids at an interface

TL;DR

This paper investigates how colloids at a fluid interface interact through deformation, especially considering electrostatic effects, revealing conditions under which attraction overcomes electrostatic repulsion.

Contribution

It introduces a general framework for analyzing deformation-induced interactions between colloids at interfaces, including electrostatic effects, and identifies conditions for net attraction.

Findings

Effective interactions can be attractive and dominate electrostatic repulsion at large distances.

Net attraction depends on colloidal charge and system isolation.

Electrostatic deformation can induce significant colloid interactions.

Abstract

Within a general framework we study the effective, deformation-induced interaction between two colloids trapped at a fluid interface. As an application, we consider the interface deformation owing to the electrostatic field of charged colloids. The effective interaction is attractive and overcomes the direct electrostatic repulsion at large separations if the system is not mechanically isolated. Otherwise, a net attraction seems possible only for large enough colloidal charges.