Flory-Huggins theory for athermal mixtures of hard spheres and larger flexible polymers

Abstract

A simple analytic theory for mixtures of hard spheres and larger polymers with excluded volume interactions is developed. The mixture is shown to exhibit extensive immiscibility. For large polymers with strong excluded volume interactions, the density of monomers at the critical point for demixing decreases as one over the square root of the length of the polymer, while the density of spheres tends to a constant. This is very different to the behaviour of mixtures of hard spheres and ideal polymers, these mixtures although even less miscible than those with polymers with excluded volume interactions, have a much higher polymer density at the critical point of demixing. The theory applies to the complete range of mixtures of spheres with flexible polymers, from those with strong excluded volume interactions to ideal polymers.

9 pages, 4 figures

References in corpus (3)

• Polymer induced depletion potentials in polymer-colloid mixtures
• Phase separation in mixtures of colloids and long ideal polymer coils
• Nucleation of the crystalline phase of proteins in the presence of semidilute non-adsorbing polymer

Cited by in corpus (8)

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• Polymer Crowding and Shape Distributions in Polymer-Nanoparticle Mixtures
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• Depletion-Induced Forces and Crowding in Polymer-Nanoparticle Mixtures: Role of Polymer Shape Fluctuations and Penetrability
• Density functional theory and demixing of binary hard rod-polymer mixtures
• Influence of Solvent Quality on Depletion Potentials in Colloid-Polymer Mixtures
• Fluid-fluid demixing curves for colloid-polymer mixtures in a random colloidal matrix