title: Spreading of colloid clusters in a quasi-one-dimensional channel.
abstract: The effect of hydrodynamic interactions on the spreading of clusters of colloid particles in a quasi-one-dimensional channel is analyzed both experimentally and theoretically. An n-particle cluster spreading diffusion coefficient is defined, in terms of the displacement Deltax(t) in time t, by D(n)[triple bond]<[Sigma(i=1)(n)Deltax(i)(t)](2)>/2nt, where the average is taken over all groups of n adjacent particles. Our study focuses on the n-dependence of D(n) with some attention to the dependence of D(n) on colloid packing fraction. We find that the ratio of D(n) to the infinite dilution self-diffusion coefficient D(S)(0) increases as n increases, eventually saturating for large n. The observed dependence of D(n) on n is in satisfactory agreement with the predictions obtained from both Stokesian dynamics simulations and hydrodynamic calculations using the method of reflections.
authors.affiliation: Department of Physics and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: Xinliang
authors.initials: X
authors.lastname: Xu
authors.forename: Binhua
authors.initials: B
authors.lastname: Lin
authors.forename: Bianxiao
authors.initials: B
authors.lastname: Cui
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Dinner
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Rice