Shear Banding: Phase Transition, Instability, or Boring Hydrodynamics?
By: Peter Olmsted
From: School of Physics and Astronomy, University of Leeds, UK
At: Complexo Interdisciplinar, Anfiteatro
[2009-01-20]
Shear banding has emerged as a persistent theme in complex fluids of various stripes and flavors, including polymer solutions, foams, surfactant solutions, and even geological phenomena (!). It is intriguing to those of us interested in phase transitions, because of the appealing but in most cases intractable effect of shear on molecular order and self assembly; the banding state is often accompanied or obscured by instabilities, which to some are the most interesting manifestations. In addition, the control of complex fluids at a nanoscale is becoming increasingly important with the promise of developing ever-more sophisticated versions of the so-called