This title appears in the Scientific Report :
2001
Please use the identifier:
http://hdl.handle.net/2128/1606 in citations.
Flow dichroism in critical colloidal fluids
Flow dichroism in critical colloidal fluids
Due to long-range correlations and slow dynamics of concentration fluctuations in the vicinity of the gas-liquid critical point, shear flow is very effective in distorting the microstructure of near-critical fluids. The anisotropic nature of the shear-field renders the microstructure highly anisotro...
| Personal Name(s): | Lenstra, T. |
|---|---|
| Dhont, J. K. G. | |
| Contributing Institute: |
Weiche Materie; IFF-WM |
| Published in: | Physical review / E, 63 (2001) S. 61401 - 61412 |
| Imprint: |
College Park, Md.
APS
2001
|
| Physical Description: |
61401 - 61412 |
| Document Type: |
Journal Article |
| Research Program: |
Polymere, Membranen und komplexe Flüssigkeiten |
| Series Title: |
Physical Review E
63 |
| Subject (ZB): | |
| Link: |
OpenAccess |
| Publikationsportal JuSER |
|
Due to long-range correlations and slow dynamics of concentration fluctuations in the vicinity of the gas-liquid critical point, shear flow is very effective in distorting the microstructure of near-critical fluids. The anisotropic nature of the shear-field renders the microstructure highly anisotropic, leading to dichroism. Experiments on the dichroic behavior can thus be used to test theoretical predictions on microstructural order under shear flow conditions. We performed both static and dynamic dichroism and turbidity measurements on a colloid-polymer mixture, existing of silica spheres (radius 51 nm) and polydimethylsiloxane polymer (molar weight 204 kg/mol). Sufficiently far away from the critical point, in the mean-field region, the experimental data are in good agreement with theory. Very close to the critical point, beyond mean field, for which no theory exists yet, an unexpected decrease of dichroism on approach of the critical point is observed. Moreover, we do not observe critical slowing down of shear-induced dichroism, right up to the critical point, in contrast to the turbidity. |