Demixing in athermal mixtures of colloids and excluded-volume polymers from a density functional theory

Abstract

We study the structure and interfacial properties of model athermal mixtures of colloids and excluded volume polymers. The colloid particles are modeled as hard spheres whereas the polymer coils are modeled as chains formed from tangentially bonded hard spheres. Within the framework of the nonlocal density functional theory we study the influence of the chain length on the surface tension and the interfacial width. We find that the interfacial tension of the colloid-interacting polymer mixtures increases with the chain length and is significantly smaller than that of the ideal polymers. For certain parameters we find oscillations on the colloid-rich parts of the density profiles of both colloids and polymers with the oscillation period of the order of the colloid diameter. The interfacial width is few colloid diameters wide and also increases with the chain length. We find the interfacial width for the end segments to be larger than that for the middle segments and this effect is more pronounced for longer chains.

arXiv comment11 pages, 8 figures

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Cited by in corpus (6)

• Accurate description of bulk and interfacial properties in colloid-polymer mixtures
• Wetting in mixtures of colloids and excluded-volume polymers from density functional theory
• Phase diagram of mixtures of colloids and polymers in the thermal crossover from good to $\theta$ solvent
• Accurate coarse-grained models for mixtures of colloids and linear polymers under good-solvent conditions
• A Monte Carlo density functional theory for the competition between inter and intramolecular association in inhomogeneous fluids
• Fluid-fluid demixing curves for colloid-polymer mixtures in a random colloidal matrix