The effective colloid interaction in the Asakura-Oosawa model. Assessment of non-pairwise terms from the virial expansion
arXiv:1503.06615 · doi:10.1063/1.4922031
Abstract
The relevance of neglecting three- and four-body interactions in the coarse-grained version of the Asakura-Oosawa model is examined. A mapping between the first few virial coefficients of the binary nonadditive hard-sphere mixture representative of this model and those arising from the coarse-grained (pairwise) depletion potential approximation allows for a quantitative evaluation of the effect of such interactions. This turns out to be especially important for large size ratios and large reservoir polymer packing fractions.
10 pages, 3 figures; v2: Results from free-volume theory included; Fig. 3 added, plus other minor changes