title: Glycerol in micellar confinement with tunable rigidity.
abstract: We investigate the glassy dynamics of glycerol in the confinement of a microemulsion system, which is stable on cooling down to the glass transition of its components. By changing the composition, we vary the viscosity of the matrix, while keeping the confining geometry intact, as is demonstrated by small angle X-ray scattering. By means of2H NMR, differential scanning calorimetry, and triplet solvation dynamics we, thus, probe the dynamics of glycerol in confinements of varying rigidity.2H NMR results show that, at higher temperatures, the dynamics of confined glycerol is unchanged compared to bulk behavior, while the reorientation of glycerol molecules becomes significantly faster than in the bulk in the deeply supercooled regime. However, comparison of different2H NMR findings with data from calorimetry and solvation dynamics reveals that this acceleration is not due to the changed structural relaxation of glycerol, but rather due to the rotational motion of essentially rigid glycerol droplets or of aggregates of such droplets in a more fluid matrix. Thus, independent of the matrix mobility, the glycerol dynamics remains unchanged except for the smallest droplets, where an increase of Tgand, thus, a slowdown of the structural relaxation is observed even in a fluid matrix.
authors.affiliation: TU Darmstadt, Institut für Festkörperphysik, Hochschulstraße 6, 64289 Darmstadt, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Lannert
authors.affiliation: TU Darmstadt, Institut für Festkörperphysik, Hochschulstraße 6, 64289 Darmstadt, Germany.
authors.forename: Allyn
authors.initials: A
authors.lastname: Müller
authors.affiliation: TU Darmstadt, Institut für Festkörperphysik, Hochschulstraße 6, 64289 Darmstadt, Germany.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Gouirand
authors.affiliation: TU Darmstadt, Institut für Festkörperphysik, Hochschulstraße 6, 64289 Darmstadt, Germany.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Talluto
authors.affiliation: TU Darmstadt, Institut für Festkörperphysik, Hochschulstraße 6, 64289 Darmstadt, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Rosenstihl
authors.affiliation: TU Darmstadt, Institut für Festkörperphysik, Hochschulstraße 6, 64289 Darmstadt, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Walther
authors.affiliation: TU Darmstadt, Institut für Festkörperphysik, Hochschulstraße 6, 64289 Darmstadt, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Stühn
authors.affiliation: TU Darmstadt, Institut für Festkörperphysik, Hochschulstraße 6, 64289 Darmstadt, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Blochowicz
authors.affiliation: TU Darmstadt, Institut für Festkörperphysik, Hochschulstraße 6, 64289 Darmstadt, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Vogel