title: Restricted swelling and its orientation effect on copolymer micellar solutions of hexagonal-packed cylinders under steady shear flow.
abstract: We investigate the structure of polystyrene-b-poly(acrylic acid, sodium salt) copolymer in aqueous solutions. We offer detailed characterization of the micellar solutions by scattering techniques and show that they form hexagonal-packed cylinders. The micelles follow the swelling law expected for cylinders, upon addition of water, down to a concentration threshold below which the distance cylinder-cylinder remains constant. The results suggest that the cylinders are aggregated. It is proposed that this micellar association is the cause of the unusual orientation of the cylinders in a steady shear flow field, where the cylinder axis is found to be parallel to the velocity gradient.
authors.affiliation: IFP-Lyon, BP 3, 69390 Vernaison, France.
authors.forename: J
authors.initials: J
authors.lastname: Grandjean
authors.forename: A
authors.initials: A
authors.lastname: Mourchid
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D008823:Micelles; D015394:Molecular Structure; D033363:Neutron Diffraction; D011137:Polystyrenes / Q000737:chemistry*; D053838:Scattering, Small Angle; D012996:Solutions / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D008823:Micelles; D011137:Polystyrenes; D012996:Solutions; D014867:Water; C006903:carbopol 940