title: Polymer depletion effects near mesoscopic particles.
abstract: The behavior of mesoscopic particles dissolved in a dilute solution of long, flexible, and nonadsorbing polymer chains is studied by field-theoretic methods. For spherical and cylindrical particles the solvation free energy for immersing a single particle in the solution is calculated explicitly. Important features are qualitatively different for self-avoiding polymer chains as compared with ideal chains. The results corroborate the validity of the Helfrich-type curvature expansion for general particle shapes and allow for quantitative experimental tests. For the effective interactions between a small sphere and a wall, between a thin rod and a wall, and between two small spheres, quantitative results are presented. A systematic approach for studying effective many-body interactions is provided. The common Asakura-Oosawa approximation modeling the polymer coils as hard spheres turns out to fail completely for small particles and still fails by about 10% for large particles.
authors.affiliation: Fachbereich Physik, Bergische Universität Wuppertal, D-42097 Wuppertal, Federal Republic of Germany.
authors.forename: A
authors.initials: A
authors.lastname: Hanke
authors.forename: E
authors.initials: E
authors.lastname: Eisenriegler
authors.forename: S
authors.initials: S
authors.lastname: Dietrich