Abstract
We use confocal microscopy and particle image velocimetry to visualize motion of 250–300 nm. fluorescent tracer particles in entangled polymers subject to a rectilinear shear flow. Our results show linear velocity profiles in polymer solutions spanning a wide range of molecular weights and number of entanglements (), but reveal large differences between the imposed and measured shear rates. These findings disagree with recent reports that shear banding is a characteristic flow response of entangled polymers, and instead point to interfacial slip as an important source of strain loss.
- Received 21 May 2008
DOI:https://doi.org/10.1103/PhysRevLett.101.218301
©2008 American Physical Society