TY  - JOUR
AU  - Westermeier, Fabian
AU  - Pennicard, David
AU  - Hirsemann, Helmut
AU  - Wagner, Ulrich H.
AU  - Rau, Christoph
AU  - Graafsma, Heinz
AU  - Schall, Peter
AU  - Lettinga, M.P.
AU  - Struth, Bernd
TI  - Connecting structure, dynamics and viscosity in sheared soft colloidal liquids: a medley of anisotropic fluctuations
JO  - Soft matter
VL  - 12
IS  - 1
SN  - 1744-6848
CY  - London
PB  - Royal Soc. of Chemistry
M1  - FZJ-2016-07616
SP  - 171 - 180
PY  - 2016
AB  - Structural distortion and relaxation are central to any liquid flow. Their full understanding requiressimultaneous probing of the mechanical as well as structural and dynamical response. We provide thefirst full dynamical measurement of the transient structure using combined coherent X-ray scatteringand rheology on electrostatically interacting colloidal fluids. We find a stress overshoot during the start-upof shear which is due to the strong anisotropic overstretching and compression of nearest-neighbordistances. The rheological response is reflected in uncorrelated entropy-driven intensity fluctuations.While the structural distortion under steady shear is well described by Smoluchowski theory, we find anincrease of the particle dynamics beyond the trivial contribution of flow. After the cessation of shear, thefull fluid microstructure and dynamics are restored, both on the structural relaxation timescale. We thusfind unique structure-dynamics relations in liquid flow, responsible for the macroscopic rheologicalbehavior of the system.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000366863800021
DO  - DOI:10.1039/C5SM01707F
UR  - https://juser.fz-juelich.de/record/825139
ER  -