Volume 36, Number 9, December III 1996
|Page(s)||719 - 724|
|Section||Condensed matter: electronic structure, electrical, magnetic and optical properties|
|Published online||01 September 2002|
Observation of shear banding in worm-like micelles by NMR velocity imaging
Department of Physics, Massey University - Palmerston North, New Zealand
Accepted: 8 November 1996
We report an observation of shear-banding, under Couette flow, of the worm-like surfactant system cetyl pyridinium chloride/sodium salicylate (respective concentrations of 100 mM and 60 mM in pure water). The method, based on NMR velocity imaging, allows the direct measurement of velocity, and consequent calculation of shear rate, at a spatial resolution of around , sufficient to resolve apparent slip at the inner wall from shear banding within the bulk of the fluid. Above a critical shear rate (around ) a high shear rate band is observed in the annulus between concentric rotating cylinders, the width of the band being of order with a corresponding shear rate of order . The precise location of the band is sensitive to boundary conditions at the inner wall and is shown to be susceptible to significant broadening.
PACS: 76.60.Pc – NMR imaging / 61.25.Hq – Macromolecular and polymer solutions; polymer melts / 47.27.Lx – Wall-bounded thin shear flows
© EDP Sciences, 1996
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.