Abstract
We present a simple thermodynamic model for shear-induced concentration banding in polymer solutions, based on a nonequilibrium chemical potential depending on the shear rate. This dependence provides a coupling between diffusion and shear, besides the more classical coupling provided by the divergence of the viscous pressure tensor. When both couplings are taken into account, shear-induced concentration banding appears in a natural way. If the initial homogeneous concentration is higher than a threshold value, shear banding appears for sufficiently high value of the shear rate γ; if the initial concentration is lower, the steady-state concentration profile under shear is smooth. The banding profile depends on the polymer molecular mass and therefore it provides a basis for the chromatographic separation of polymers of different molecular mass. © 2001 Elsevier Science Ltd.
| Original language | English |
|---|---|
| Pages (from-to) | 6239-6245 |
| Journal | Polymer |
| Volume | 42 |
| DOIs | |
| Publication status | Published - 20 Apr 2001 |
Keywords
- Macromolecules
- Shear-induced concentration banding
- Viscous pressure