Abstract
We consider a simplified coarse-grained model for colloid-polymer mixtures, in which polymers are represented as monoatomic molecules interacting by means of pair potentials. We use it to study polymer-colloid segregation in the presence of a quenched matrix of colloidal hard spheres. We fix the polymer-to-colloid size ratio to 0.8 and consider matrices such that the fraction of the volume that is not accessible to the colloids due to the matrix is equal to 40. As in the Asakura-Oosawa-Vrij (AOV) case, we find that binodal curves in the polymer and colloid volume-fraction plane have a small dependence on disorder. As for the position of the critical point, the behavior differs from that observed in the AOV case: While the critical colloid volume fraction is essentially the same in the bulk and in the presence of the matrix, the polymer volume fraction at criticality increases as increases. At variance with the AOV case, no capillary colloid condensation or evaporation is generically observed.
3 More- Received 26 July 2012
DOI:https://doi.org/10.1103/PhysRevE.86.041804
©2012 American Physical Society