Homogeneous or Demixed? Shampoos and Plastics Under Stress

IFF-News January 6, 2010

Jülich scientists investigate basic physical principles of the flow behaviour of complex liquids

Bild zur News
Everyday products like shampoos and plastics consist of highly complex ingredients such as polymers and long-chain molecules. Well-balanced recipes are necessary to create a stable mixture. If the pressure is too high or if the mixture is stirred too vigorously, then the liquids frequently separate out again. The shearing forces at the container walls are of great significance here.
Photos: ENS Lyon(left), Forschungszentrum Jülich (right)

Everyday products like shampoos and plastics consist of highly complex ingredients such as polymers and long-chain molecules. Well-balanced recipes are necessary to create a stable mixture. If the pressure is too high or if the mixture is stirred too vigorously, then the liquids frequently separate out again. The shearing forces at the container walls are of great significance here. Scientists from the IFF and the French university Ecole Normale Supérieure de Lyon have been able to demonstrate experimentally for the first time how a microscopic "slip process" leads to more stable liquids. These findings, which have now been published in the high-impact journal "Physical Review Letters", can help to more accurately predict the flow behaviour of complex liquids.

Original publication:
Competition between Shear Banding and Wall Slip in Wormlike Micelles
M. P. Lettinga und S. Manneville
Phys. Rev. Lett. 103, 248302 (2009)

Full press release (in German):
http://www.fz-juelich.de/portal/presse/pressemitteilungen

Institutions:
ICS-3

École normale supérieure de Lyon

Last Modified: 14.03.2022