title: Glass transition of poly(ethylmethacrylate) admixed and bound to nanoparticles.
abstract: The chain dynamics at the glass transition of poly(ethylmethacrylate) in the bulk is compared to that of mixtures of the polymer with nanoparticles by advanced NMR methods. In order to make the two components compatible, the particles were functionalized with the polymer itself. Particular emphasis is placed on the extended local chain conformations of this polymer accessible by (13)C NMR spectroscopy. The isotropization dynamics of these extended conformations is only slightly changed in the mixtures, but is significantly slowed down by attachment of the chains to the nanoparticles themselves. The slowing down is studied at various distances from the nanoparticle and is observed for most of the attached chains segments except for the chain ends. The results are put into perspective to the glass transition in polymers attached to surfaces, thin polymer layers, and the chain dynamics of star polymers.
authors.affiliation: Max-Planck-Institute for Polymer Research, P.O. Box 3148, 55028 Mainz, Germany.
authors.forename: Cornelius
authors.initials: C
authors.lastname: Friedrichs
authors.forename: Sebastian
authors.initials: S
authors.lastname: Emmerling
authors.forename: Gunnar
authors.initials: G
authors.lastname: Kircher
authors.forename: Robert
authors.initials: R
authors.lastname: Graf
authors.forename: Hans
authors.initials: H
authors.lastname: Wolfgang Spiess
mesh_terms: D005898:Glass / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008768:Methylmethacrylates / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*
chemical_list: D008768:Methylmethacrylates; C009931:poly(ethylmethacrylate)