title: Direct observation of confined single chain dynamics by neutron scattering.
abstract: Neutron spin echo has revealed the single chain dynamic structure factor of entangled polymer chains confined in cylindrical nanopores with chain dimensions either much larger or smaller than the lateral pore sizes. In both situations, a slowing down of the dynamics with respect to the bulk behavior is only observed at intermediate times. The results at long times provide a direct microscopic measurement of the entanglement distance under confinement. They constitute the first experimental microscopic evidence of the dilution of the total entanglement density in a polymer melt under strong confinement, a phenomenon that so far was hypothesized on the basis of various macroscopic observations.
authors.affiliation: Instituto de Ciencia y Tecnología de Polímeros, CSIC, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Martín
authors.forename: M
authors.initials: M
authors.lastname: Krutyeva
authors.forename: M
authors.initials: M
authors.lastname: Monkenbusch
authors.forename: A
authors.initials: A
authors.lastname: Arbe
authors.forename: J
authors.initials: J
authors.lastname: Allgaier
authors.forename: A
authors.initials: A
authors.lastname: Radulescu
authors.forename: P
authors.initials: P
authors.lastname: Falus
authors.forename: J
authors.initials: J
authors.lastname: Maiz
authors.forename: C
authors.initials: C
authors.lastname: Mijangos
authors.forename: J
authors.initials: J
authors.lastname: Colmenero
authors.forename: D
authors.initials: D
authors.lastname: Richter