title: Banding in entangled polymer fluids under oscillatory shearing.
abstract: We report a flow phenomenon in entangled polymer solutions that has never been described in the literature. A large-amplitude oscillatory shear was imposed on the polymer sample at a frequency higher than the overall chain relaxation rate. The resulting chain orientation led to a new environment in which the initially well-entangled chains managed to disentangle inhomogeneously in space. A layer lacking chain entanglement developed to take the load of the imposed strain. As a result of this nonlinearity, the rest of the sample avoided significant deformation and its chain entanglement remained intact.
authors.affiliation: Department of Polymer Science, University of Akron, Ohio 44325, USA.
authors.forename: Prashant
authors.initials: P
authors.lastname: Tapadia
authors.forename: Sham
authors.initials: S
authors.lastname: Ravindranath
authors.forename: Shi-Qing
authors.initials: SQ
authors.lastname: Wang