Dissertation / PhD Thesis

DESY-2014-01645

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Dynamics of colloids in molecular glass forming liquids studied via X-ray photon correlation spectroscopy

Conrad, H. (Corresponding author)Extern* ; Gruebel, G. (Thesis advisor)DESY*

2014
University of Hamburg Hamburg

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Please use a persistent id in citations: http://nbn-resolving.de/urn:nbn:de:gbv:18-65907  doi:10.3204/DESY-2014-01645

Abstract: In this work the static and dynamical properties of the glass formers polypropylene glycol and dibutyl phthalate are studied in the supercooled state. Colloidal tracer particles suspended in these glass formers allow the investigation of their dynamics with coherent synchrotron radiation by means of X-ray photon correlation spectroscopy. The static structure factors, the relaxation times and the dispersion relations of the tracer particles were determined as function of the solvent temperature. The results show that the nature of the particles dynamics in the glass former changes close to the glass transition temperature (Tg) between 1.08 − 1.12 Tg. While the static structure factor remains unchanged in this temperature range, the particle dynamics changes from free diffusion at T > 1.12 Tg to hyper diffusive and correlated particle motion at T < 1.08 Tg. By comparing samples of different particle sizes and concentrations it becomes evident that this change in the dynamics is related to changes of the solvent properties. These changes are accompanied by an increasing heterogeneity in the dynamics of the tracer particles. The findings are in agreement with an interpretation that domains of correlated dynamics in the supercooled glass formers grow in size with decreasing temperature.

Keyword(s): Dissertation

Note: Dissertation, University of Hamburg, 2014

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Contributing Institute(s):

1. DOOR-User (DOOR)
2. Coherent X-ray Scattering (FS-CXS)

Research Program(s):

1. PETRA Beamline P10 (POF2-54G14) (POF2-54G14)
2. 6215 - Soft Matter, Health and Life Sciences (POF3-621) (POF3-621)

Experiment(s):

1. PETRA Beamline P10 (PETRA III)

Appears in the scientific report 2014

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Database coverage:

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