title: Colloids dragged through a polymer solution: Experiment, theory, and simulation.
abstract: We present microrheological measurements of the drag force on colloids pulled through a solution of lambda-DNA (used here as a monodisperse model polymer) with an optical tweezer. The experiments show a drag force that is larger than expected from the Stokes formula and the independently measured viscosity of the DNA solution. We attribute this to the accumulation of DNA in front of the colloid and the reduced DNA density behind the colloid. This hypothesis is corroborated by a simple drift-diffusion model for the DNA molecules, which reproduces the experimental data surprisingly well, as well as by corresponding Brownian dynamics simulations.
authors.affiliation: Institut für Experimentalphysik I, Universität Leipzig, 04103 Leipzig, Germany.
authors.forename: Christof
authors.initials: C
authors.lastname: Gutsche
authors.forename: Friedrich
authors.initials: F
authors.lastname: Kremer
authors.forename: Matthias
authors.initials: M
authors.lastname: Krüger
authors.forename: Markus
authors.initials: M
authors.lastname: Rauscher
authors.forename: Rudolf
authors.initials: R
authors.lastname: Weeber
authors.forename: Jens
authors.initials: J
authors.lastname: Harting
mesh_terms: D002627:Chemistry, Physical / Q000379:methods*; D003102:Colloids / Q000737:chemistry*; D004247:DNA / Q000737:chemistry; D004058:Diffusion; D015233:Models, Statistical; D008970:Molecular Weight; D009038:Motion; D052898:Optical Tweezers; D011108:Polymers / Q000737:chemistry*; D012212:Rheology; D012996:Solutions; D012997:Solvents / Q000737:chemistry
chemical_list: D003102:Colloids; D011108:Polymers; D012996:Solutions; D012997:Solvents; D004247:DNA