2010/06/30 by Andrea Gambassi, S. Dietrich
Physics and Astronomy · #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevlett.105.059601
published as Phys. Rev. Lett. 105, 059601 (2010) · 1 page, 1 figure; For the reply see arXiv:1007.0770
arxiv created 2010/06/30 · arxiv updated 2010/10/05
A recent Letter [Phys. Rev. Lett. 103, 156101 (2009)] reports the experimental observation of aggregation of colloidal particles dispersed in a liquid mixture of heavy water and 3-methylpyridine. The experimental data are interpreted in terms of a model which accounts solely for the competing effects of the interparticle electrostatic repulsion and of the attractive critical Casimir force. Here we show, however, that the reported aggregation actually occurs within ranges of values of the correlation length and of the Debye screening length ruled out by the proposed model and that a significant part of the experimental data presented in the Letter cannot be consistently interpreted in terms of such a model.