title: Entanglement-controlled subdiffusion of nanoparticles within concentrated polymer solutions.
abstract: We describe x-ray photon correlation spectroscopy (XPCS) experiments tracking the motion of gold nanoparticles within solutions of high-molecular-weight polystyrene. Over displacements from nanometers to tens of nanometers, the particles undergo subdiffusive motion that is dictated by the temporal evolution of the entangled polymer mesh in the immediate vicinity of the particles. The results thus provide a novel microscopic dynamical characterization of this key structural property of polymers and more broadly demonstrate the capability of XPCS-based microrheology to interrogate heterogeneous mechanical environments in nanostructured soft materials.
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: R Bruce
authors.initials: RB
authors.lastname: Lennox
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