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 (8≤Z≤56), 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. © 2008 The American Physical Society.
|Original language||English (US)|
|Journal||Physical Review Letters|
|State||Published - Nov 17 2008|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This study was supported by the National Science Foundation (DMR0551185 and DMR0606040) and by KAUST-CU Center for Energy and Sustainability. We are grateful to Erik Herz and Ulrich Wiesner for providing fluorescent nanoparticle tracers used in the study.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.