Abstract
In this research, experimental studies were performed to examine the rheological behavior of equimolar solutions of cetylpyridinium chloride (CPyCl) and sodium salicylate (NaSal) solutions with concentration. The surfactant solutions were prepared by dissolving 2 mM/2 mM - 80 mM/80 mM of surfactant/counterion in double-distilled water. It has been observed that the zero shear viscosity shows abrupt changes at two critical values of C* and C**. These changes are caused by the switching of relaxation mechanism with concentration of CPyCl/NaSal solutions at those concentrations. The wall slip velocities of dilute and semi-dilute CPyCl/NaSal solutions show a dramatic increase with shear rate where the shear viscosity exhibits shear thickening behavior for dilute solutions and shear thinning behavior for semi-dilute solutions, respectively. Considering that the dramatic increase in wall slip velocity should be related to the formation of shear-induced structure (SIS) in the surfactant solution, the shear thickening behavior of semi-dilute solutions is caused by elastic instability unlike the case of dilute solutions.
| Original language | English |
|---|---|
| Pages (from-to) | 151-156 |
| Number of pages | 6 |
| Journal | Korea Australia Rheology Journal |
| Volume | 15 |
| Issue number | 3 |
| Publication status | Published - 2003 |
Keywords
- Elastic instability
- Shear induced structure
- Wall slip
- Zero shear viscosity
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics