Comment to "Multipolar expansion of the electrostatic interaction between charged colloids at interfaces"

TL;DR

This paper critiques a recent claim about electrostatic interactions at interfaces, arguing that anisotropic dipolar interactions can exist at the same order, challenging previous conclusions.

Contribution

It provides a correction to prior analysis, showing that anisotropic electrostatic interactions are possible up to order d^-3.

Findings

Anisotropic dipolar interactions can exist at order d^-3.

Previous analysis was incomplete, overlooking these interactions.

Challenges the claim that interactions are always isotropic to order d^-3.

Abstract

We present a comment to a recent paper by Dominguez et. al. They claimed that the electrostatic interaction between charged colloids trapped at an interface formed by a dielectric and a screening phase is always isotropic to order $d^-3$. Base on this result, they claimed that in-plane dipolar attraction of order $d^-3$ between colloids cannot exist, in contrast to previous proposals. We point out that their analysis is not completed and anisotropic (dipolar) interaction between colloids can exist up to order $d^-3$.