Coupling Effects of Depletion Interactions in Colloidal Suspensions

Haixia Gao,Zeshun Chen,Changming Xiao,Chunshu Li

doi:10.4236/jmp.2012.39119

Haixia Gao, Zeshun Chen + Show 2 more

Open Access

https://doi.org/10.4236/jmp.2012.39119

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Abstract

The depletion interactions of the three-sphere system in which the three spheres are on one line are studied by Monte Carlo simulations. The depletion interactions are determined by ARM, and the coupling effect was proved by the numerical result that the depletion interactions in the three-sphere system are larger than that of the corresponding two-sphere system. Furthermore, we find that the mechanisms of the coupling effect and the effect on depletion force from the geometry factor are the same. In addition, the numerical results also show that this coupling effect will be affected by both the volume fraction and separation of three-sphere system.

Highlights

It’s well known that the depletion interaction arises when two large spheres are immersed in the sea of small spheres
With the aid of Monte Carlo simulations and acceptance ratio method, the depletion interactions of the three-sphere system are studied in this paper, and the numerical results show that the depletion interactions in the three-sphere system are larger than that of the corresponding two-sphere system, i.e., the depletion interaction of the three-sphere system are coupled with each other
It is known that the depletion force between two large-spheres will be strengthened if they are confined between two parallel plates [3], and the three-body depletion interactions in the equilateral triplets where the three large spheres are dispersed in equilateral-triangular configurations were studied, and the results show that the three-body interaction is attractive when the distance between them is small [4,5,6,7]

Summary

Introduction

It’s well known that the depletion interaction arises when two large spheres are immersed in the sea of small spheres. We will study the depletion interactions among the three large spheres which are schematically illustrated by Figure 1(a). We will find that, in the three-sphere system, the depletion forces acted on B are larger than that of the system without C This three-sphere system is different to the equilateral triplets mentioned in Refs [4,5,6,7], and the results obtained from this system provide information about the three-body interaction and about the coupling effect of depletion interactions. The model and theory are presented in the second section, and the numerical results and a simple discussion will be given in the third section, a summary of our study is given in the last section

Theory and Model

Results and Discussions

Conclusion