title: Anomalous preasymptotic colloid transport by hydrodynamic dispersion in microfluidic capillary flow.
abstract: The anomalous preasymptotic transport of colloids in a microfluidic capillary flow due to hydrodynamic dispersion is measured by noninvasive nuclear magnetic resonance (NMR). The data indicate a reduced scaling of mean squared displacement with time from the 〈z(t)(2)〉(c) ∼ t(3) behavior for the interaction of a normal diffusion process with a simple shear flow. This nonequilibrium steady-state system is shown to be modeled by a continuous time random walk (CTRW) on a moving fluid. The full propagator of the motion is measured by NMR, providing verification of the assumption of Gaussian jump length distributions in the CTRW model. The connection of the data to microrheology measurements by NMR, in which every particle in a suspension contributes information, is established.
authors.affiliation: Department of Chemical and Biological Engineering, Montana State University, Bozeman, Montana 59717-3920, USA.
authors.forename: Einar Orn
authors.initials: EO
authors.lastname: Fridjonsson
authors.affiliation: Department of Chemical and Biological Engineering, Montana State University, Bozeman, Montana 59717-3920, USA and Center for Biofilm Engineering, Montana State University, Bozeman, Montana 59717-3980, USA.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Seymour
authors.affiliation: Center for Biofilm Engineering, Montana State University, Bozeman, Montana 59717-3980, USA and Department of Mechanical and Industrial Engineering, Montana State University, Bozeman, Montana 59717-3800, USA.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Codd
mesh_terms: D003102:Colloids; D004058:Diffusion; D057446:Hydrodynamics; D044085:Microfluidics; D009038:Motion; D016011:Normal Distribution; D011336:Probability
chemical_list: D003102:Colloids