This title appears in the Scientific Report :
2016
The Connection between Shear Thinning and Biaxial Orientation for quasi ideal Rods
The Connection between Shear Thinning and Biaxial Orientation for quasi ideal Rods
We use rheo-SANS measurements to determine the response of isotropic fd-virus suspensions to steady state shear flow. The complete orientational order parameter tensor is obtained as a function of shear rate by resolving the orientational ordering of the quasi-ideal rods in the two relevant scatteri...
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Personal Name(s): | Lang, Christian (Corresponding author) |
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Lettinga, M. P. | |
Contributing Institute: |
Weiche Materie; ICS-3 |
Imprint: |
2016
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Conference: | Rheo-Small Angle Scattering Conference, Grenoble (France), 2016-09-19 - 2016-09-21 |
Document Type: |
Conference Presentation |
Research Program: |
Directed Colloidal Structure at the Meso-Scale Functional Macromolecules and Complexes |
Publikationsportal JuSER |
We use rheo-SANS measurements to determine the response of isotropic fd-virus suspensions to steady state shear flow. The complete orientational order parameter tensor is obtained as a function of shear rate by resolving the orientational ordering of the quasi-ideal rods in the two relevant scattering planes, the flow-gradient and the flow-vorticity plane.Microscopic ordering can be identified as the origin of the observed shear thinning. We obtain a master curve for different concentrations taking into account the appearent collective rotational diffusion coefficient. However, we need to do a scaling of the zero shear viscosity which matches the concentration dependence of self-diffusion of the rods. Using the Doi-Edwards-Kuzuu theory, a qualitative description of the rheological response is possible but the observation suggests that the contribution of shear induced energy to the positional entropy is larger than predicted. Moreover, we observe signs of biaxiality due to the combination of shear geometries. |