title: Nanoscale Study of Polymer Dynamics.
abstract: The thermal motion of polymer chains in a crowded environment is anisotropic and highly confined. Whereas theoretical and experimental progress has been made, typically only indirect evidence of polymer dynamics is obtained either from scattering or mechanical response. Toward a complete understanding of the complicated polymer dynamics in crowded media such as biological cells, it is of great importance to unravel the role of heterogeneity and molecular individualism. In the present work, we investigate the dynamics of synthetic polymers and the tube-like motion of individual chains using time-resolved fluorescence microscopy. A single fluorescently labeled polymer molecule is observed in a sea of unlabeled polymers, giving access to not only the dynamics of the probe chain itself but also to that of the surrounding network. We demonstrate that it is possible to extract the characteristic time constants and length scales in one experiment, providing a detailed understanding of polymer dynamics at the single chain level. The quantitative agreement with bulk rheology measurements is promising for using local probes to study heterogeneity in complex, crowded systems.
authors.affiliation: High Field Magnet Laboratory (HFML - EMFL), Radboud University , Toernooiveld 7, NL-6525 ED Nijmegen, The Netherlands.|Institute for Molecules and Materials, Department of Molecular Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Keshavarz
authors.affiliation: High Field Magnet Laboratory (HFML - EMFL), Radboud University , Toernooiveld 7, NL-6525 ED Nijmegen, The Netherlands.|Division of Molecular Imaging and Photonics, Department of Chemistry, Katholieke Universiteit Leuven , Celestijnenlaan 200 F, B-3001 Heverlee, Belgium.
authors.forename: Hans
authors.initials: H
authors.lastname: Engelkamp
authors.affiliation: Institute for Molecules and Materials, Department of Molecular Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Jialiang
authors.initials: J
authors.lastname: Xu
authors.affiliation: Division of Molecular Imaging and Photonics, Department of Chemistry, Katholieke Universiteit Leuven , Celestijnenlaan 200 F, B-3001 Heverlee, Belgium.
authors.forename: Els
authors.initials: E
authors.lastname: Braeken
authors.affiliation: Institute for Molecules and Materials, Department of Molecular Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Matthijs B J
authors.initials: MB
authors.lastname: Otten
authors.affiliation: Division of Molecular Imaging and Photonics, Department of Chemistry, Katholieke Universiteit Leuven , Celestijnenlaan 200 F, B-3001 Heverlee, Belgium.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uji-I
authors.affiliation: Institute for Molecules and Materials, Department of Molecular Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: Schwartz
authors.affiliation: Institute for Molecules and Materials, Department of Molecular Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Koepf
authors.affiliation: Division of Molecular Imaging and Photonics, Department of Chemistry, Katholieke Universiteit Leuven , Celestijnenlaan 200 F, B-3001 Heverlee, Belgium.
authors.forename: Anja
authors.initials: A
authors.lastname: Vananroye
authors.affiliation: Department of Chemical Engineering, Katholieke Universiteit Leuven , de Croylaan 46, B-3001 Heverlee, Belgium.|Department of Materials - Hönggerberg, ETH Zürich , Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland.
authors.forename: Jan
authors.initials: J
authors.lastname: Vermant
authors.affiliation: Institute for Molecules and Materials, Department of Molecular Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Roeland J M
authors.initials: RJ
authors.lastname: Nolte
authors.affiliation: Division of Molecular Imaging and Photonics, Department of Chemistry, Katholieke Universiteit Leuven , Celestijnenlaan 200 F, B-3001 Heverlee, Belgium.
authors.forename: Frans
authors.initials: F
authors.lastname: De Schryver
authors.affiliation: High Field Magnet Laboratory (HFML - EMFL), Radboud University , Toernooiveld 7, NL-6525 ED Nijmegen, The Netherlands.
authors.forename: Jan C
authors.initials: JC
authors.lastname: Maan
authors.affiliation: Division of Molecular Imaging and Photonics, Department of Chemistry, Katholieke Universiteit Leuven , Celestijnenlaan 200 F, B-3001 Heverlee, Belgium.|Nano-Science Center/Department of Chemistry, University of Copenhagen , Universitetsparken 5, 2100 Copenhagen, Denmark.
authors.forename: Johan
authors.initials: J
authors.lastname: Hofkens
authors.affiliation: High Field Magnet Laboratory (HFML - EMFL), Radboud University , Toernooiveld 7, NL-6525 ED Nijmegen, The Netherlands.
authors.forename: Peter C M
authors.initials: PC
authors.lastname: Christianen
authors.affiliation: Institute for Molecules and Materials, Department of Molecular Materials, Radboud University , Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors.forename: Alan E
authors.initials: AE
authors.lastname: Rowan
keywords: reptation; single molecule studies; time-resolved fluorescence microscopy