Phase behaviour of mixtures of colloidal spheres and excluded-volume polymer chains
We study the phase behaviour of mixtures of colloidal spheres and polymers that have an excluded-volume interaction dispersed in a (background) solvent using the concept of free volume theory. The depletion layer thickness is calculated from the negative adsorption of polymer segments around a spher...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2002
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| Summary: | We study the phase behaviour of mixtures of colloidal spheres and polymers that have an excluded-volume interaction dispersed in a (background) solvent using the concept of free volume theory. The depletion layer thickness is calculated from the negative adsorption of polymer segments around a sphere. The correlation length and thermodynamic properties of the excluded-volume interacting polymer chains in solution are taken into account by using results from the renormalization group theory. For small polymer-colloid size ratios the difference from an ideal description of the polymers is small, while for larger size ratios the gas-liquid coexistence region shifts in the direction of higher polymer concentrations and at the same time the liquid-crystal coexistence region becomes more extended. Both the gas-liquid region and the gasliquid-crystal region become less extended. These features are compared to experiment. |
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