title: Shear-induced metastable states of end-grafted polystyrene.
abstract: The in situ molecular scale response of end-grafted polystyrene to shear against a deuterated polystyrene melt was investigated with neutron reflectometry. The derived grafted polystyrene density profiles showed that the grafted polystyrene was retained on the quartz wafer during the measurements. The profiles suggested that the end-grafted polystyrene response to shear results in a series of metastable states, rather than equilibrium states assumed in the current theory. Except for some possible extension and/or contraction of the grafted polystyrene with shear, there was no obvious correlation between the grafted polymer structure and the shear thinning behavior observed in these samples.
authors.affiliation: Los Alamos Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Sasa
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Yearley
authors.forename: Michael S
authors.initials: MS
authors.lastname: Jablin
authors.forename: Robert D
authors.initials: RD
authors.lastname: Gilbertson
authors.forename: Adrienne S
authors.initials: AS
authors.lastname: Lavine
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Majewski
authors.forename: Rex P
authors.initials: RP
authors.lastname: Hjelm