Colloidal aggregation and critical Casimir forces - Reply

TL;DR

This paper defends previous experimental findings on colloidal aggregation driven by critical Casimir forces, addressing critiques and clarifying the model's applicability in the context of negligible van der Waals forces.

Contribution

It provides a rebuttal to critiques of their simple model, reaffirming the experimental evidence for critical Casimir induced colloidal aggregation.

Findings

Experimental evidence supports critical Casimir forces causing colloidal aggregation.

The simple model remains valid within its domain of application.

Addressed and clarified critiques regarding the model's limitations.

Abstract

In a recent Letter [Phys. Rev. Lett. 103, 156101 (2009)], we presented experiments on critical Casimir induced colloidal aggregation in a system with negligibly small van der Waals forces. We presented a simple model based on a competition between repulsive electrostatic and attractive critical Casimir forces to account for the observed aggregation. A recent comment [A. Gambassi, S. Dietrich, arXiv:1006.5897v1] proposed that the simple model should be regarded with caution as to its domain of application, and that it can be refined in a number of different ways. Here, we revisit our experimental finding and give a reply to the comment.