Structure and thermodynamics of colloid-polymer mixtures: A macromolecular approach

• Published in: Europhysics letters Vol. 51; no. 6; pp. 621 - 627
• Main Authors: Fuchs, M, Schweizer, K. S
• Format: Journal Article
• Language: English
• Published: Les Ulis IOP Publishing 15.09.2000; EDP Sciences; EDP sciences
• Subjects: 61.20.-p; 61.25.Hq; 82.70.Dd; Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Properties and characterization; Solution and gel properties; Chemical solution; Thermodynamic model; Solution structure; Theoretical study; Polymer; Modeling; Colloid particle; Concentrated suspension
• ISSN: 0295-5075; 1286-4854
• DOI: 10.1209/epl/i2000-00383-8

The change of the structure of concentrated colloidal suspensions upon addition of non-adsorbing polymer is studied within a two-component, Ornstein-Zernicke–based liquid state approach. The polymers' conformational degrees of freedom are considered and excluded volume is enforced at the segment level. The polymer correlation hole, depletion layer, and excess chemical potentials are described in agreement with polymer physics theory in contrast to models treating the macromolecules as effective spheres. Known depletion attraction effects are recovered for low particle density, while at higher densities novel many-body effects emerge which become dominant for large polymers.