title: Nanoparticle motion within glassy polymer melts.
abstract: X-ray photon correlation spectroscopy is employed to investigate the motion of dilute suspensions of gold nanoparticles in low-molecular-weight polystyrene melts. At high temperatures, the observed motion is diffusive, with a rate that follows a Vogel-Fulcher temperature dependence. Closer to the glass transition temperature Tg, diffusion is superseded by a hyperdiffusive process that first becomes observable near a crossover temperature Tc approximately 1.1Tg and is identified with heterogeneous strain in the melts. Following rapid cooling to temperatures sufficiently below Tc, but still above Tg, the hyperdiffusive dynamics displays a time dependence similar to aging in polymer glasses.
authors.affiliation: Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Guo
authors.forename: Gilles
authors.initials: G
authors.lastname: Bourret
authors.forename: Muriel K
authors.initials: MK
authors.lastname: Corbierre
authors.forename: Simona
authors.initials: S
authors.lastname: Rucareanu
authors.forename: R Bruce
authors.initials: RB
authors.lastname: Lennox
authors.forename: Khalid
authors.initials: K
authors.lastname: Laaziri
authors.forename: Luc
authors.initials: L
authors.lastname: Piche
authors.forename: Mark
authors.initials: M
authors.lastname: Sutton
authors.forename: James L
authors.initials: JL
authors.lastname: Harden
authors.forename: Robert L
authors.initials: RL
authors.lastname: Leheny