% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@INPROCEEDINGS{Lettinga:888934,
author = {Lettinga, M. P. and Korculanin, Olivera},
title = {{A}nomalous rheological response of nematic platelets
studied by 3{D} {R}heo-{SAXS} and {XPCS}},
reportid = {FZJ-2020-05333},
year = {2020},
abstract = {Dispersions of colloidal Gibbsite platelets in the nematic
phase show intriguing anomalous behaviour when sheared, due
to the strong wall anchoring of such systems. When
subjecting this system to Large Amplitude Oscillatory Shear,
an elastic response is observed at low strain amplitudes,
but time-resolved rheo-SAXS experiments show that the
structural response is symmetry broken. At high strain
amplitude a yielding transition between elastic and plastic
deformation is observed during a period, accompanied by a
flipping of the director. When applying Large Amplitude
Oscillatory Stress, the system displays a strong offsets in
the rheological response as well as asymmetrical behavior in
the microscopic structural response. With increasing stress
amplitude the offset of the rheological response diminishes
and the microscopic response becomes more symmetric.
However, this strongly depends on the frequency of the
stress input, and hence the time necessary for the system to
yield. Here we tracked the full 3D rotational motion of the
director by employing plate-plate and concentric cylinder
Couette geometries as well as a vertical X-ray beam.
Finally, we show that the response throughout the gap is
strongly inhomogeneous, as well in structure as in velocity.
To this end we performed XPCS measurements in ``tangential"
scattering geometry in a Couette cell to obtain velocity
profiles.},
month = {Dec},
date = {2020-12-14},
organization = {International Congress on Rheology
2020, Rio de Janeiro (virtual)
(Brasil), 14 Dec 2020 - 17 Dec 2020},
subtyp = {Plenary/Keynote},
cin = {IBI-4},
cid = {I:(DE-Juel1)IBI-4-20200312},
pnm = {551 - Functional Macromolecules and Complexes (POF3-551)},
pid = {G:(DE-HGF)POF3-551},
typ = {PUB:(DE-HGF)6},
url = {https://juser.fz-juelich.de/record/888934},
}