Abstract
New data are presented on apparent shear thickening of adsorbed layers and polymer solutions in various porous media of different geometries. We have observed that there is no apparent shear thickening if the pores are straight with smooth walls, i.e., in pure shear flow. Variations in cross-sectional area of channels or wall rugosities in straight pores are necessary to produce solvent flow perpendicular to the surface, i.e., a locally elongation flow. We advance the hypothesis that the apparent shear thickening is related to an elongational-flow-induced “coil stretch”, a reversible transition of the adsorbed macromolecules, and rationalize this in light of previously published results.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 262-266 |
| Number of pages | 5 |
| Journal | Macromolecules |
| Volume | 22 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 1989 |
| Externally published | Yes |