title: Direct measurement of entropic forces induced by rigid rods.
abstract: We present the first direct depletion potential measurements for a single colloidal sphere close to a wall in a suspension of rigid colloidal rods. Since all particle interactions are as good as hard-core-like, the depletion potentials are of entirely entropic origin. We developed a density functional theory approach that accurately accounts for this experimental situation. The depletion potentials calculated for different rod number densities are in very good quantitative agreement with the experimental results.
authors.affiliation: Physics Department, University of Konstanz, D-78457 Konstanz, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Helden
authors.forename: R
authors.initials: R
authors.lastname: Roth
authors.forename: G H
authors.initials: GH
authors.lastname: Koenderink
authors.forename: P
authors.initials: P
authors.lastname: Leiderer
authors.forename: C
authors.initials: C
authors.lastname: Bechinger
mesh_terms: D003102:Colloids / Q000737:chemistry*; D019277:Entropy; D008962:Models, Theoretical; D010316:Particle Size
chemical_list: D003102:Colloids