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Effective interactions, structure, and isothermal compressibility of colloidal suspensions.
- Source :
- Journal of Chemical Physics; 9/15/2000, Vol. 113 Issue 11, 2 Charts, 10 Graphs
- Publication Year :
- 2000
-
Abstract
- We study the effective interactions, structure, and the isothermal compressibility of a binary mixture interacting with pairwise additive pair potentials. By integrating out the degrees of freedom of species 2 in the partition sum we first show that a binary mixture can be mapped formally onto an effective one-component system with an effective Hamiltonian consisting of a structure-independent term, which contributes to the total pressure and chemical potential of the system, but does not affect the phase behavior, and a structure-dependent potential of mean force, which contains pair-, triplet-, and higher-body interactions. We then show that the 1-1 structure factor and pair correlation function, and the total isothermal compressibility of the mixture are equal to those of the effective one-component system, provided the mapping is exact. We illustrate and confirm these results by calculating the structure factors and pair correlation functions of the binary Asakura-Oosawa model, which is a simple model for colloid-polymer mixtures, and those of the corresponding one-component system for a size ratio such that the mapping onto an effective one-component Hamiltonian with a strictly pairwise potential of mean force is exact. The distinction between the osmotic and total compressibility of the mixture is emphasized. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]
- Subjects :
- COLLOIDS
SUSPENSIONS (Chemistry)
MIXTURES
Subjects
Details
- Language :
- English
- ISSN :
- 00219606
- Volume :
- 113
- Issue :
- 11
- Database :
- Complementary Index
- Journal :
- Journal of Chemical Physics
- Publication Type :
- Academic Journal
- Accession number :
- 4412184
- Full Text :
- https://doi.org/10.1063/1.1288921