Demixing transition, structure, and depletion forces in binary mixtures of hard-spheres: the role of bridge functions.

摘要: Asymmetric binary mixtures of hard-spheres exhibit several interesting thermodynamic phenomena, such as multiple kinds glassy states. When the degrees freedom small spheres are integrated out from description, their effects incorporated into an effective pair interaction between large known depletion potential. The latter has been widely used to study both phase behavior and dynamic arrest big particles. Depletion forces can be accounted for by a contraction description in multicomponent Ornstein-Zernike equation [R. Castaneda-Priego, A. Rodriguez-Lopez, J. M. Mendez-Alcaraz, Phys. Rev. E 73, 051404 (2006)]. Within this theoretical scheme, approximation difference bare bridge functions is needed. In limit infinite dilution, irrelevant typical Asakura-Osawa potential recovered. At higher particle concentrations, however, becomes important, especially where shell first neighbors formed, and, shown here, cannot simply neglected. work, we use variant Verlet expression highlight importance calculation at high densities close spinodal decomposition. We demonstrate that modified closure predicts demixing hard different size ratios compare its predictions with liquid state density functional theories, computer simulations, experiments. also show it provides accurate correlation even near instability; explicitly corroborated results molecular dynamics simulations whole mixture. Particularly, our findings point toward possible universal around line.