title: Shear thinning and orientational ordering of wormlike micelles.
abstract: Shear thinning and orientation of cylindrical surfactant and block copolymer micelles was investigated by rheo-SANS (small-angle neutron scattering) experiments. Shear thinning and orientation occur for shear rates (.)gamma tau(dis)>>1, where tau(dis) is the disentanglement time of the micelles. Micelles align in the flow direction with an orientational distribution that can be well described by an Onsager-type distribution function. Over nearly the whole range of concentrations and for all cylindrical micelles investigated, the shear viscosity eta follows a simple eta approximately e(-aS) behavior as a function of the orientational order parameter S with the same prefactor a.
authors.affiliation: Institut für Physikalische Chemie, Universität Hamburg, D-20146 Hamburg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Förster
authors.forename: M
authors.initials: M
authors.lastname: Konrad
authors.forename: P
authors.initials: P
authors.lastname: Lindner