Rheological and flow birefringence studies of a shear‐thickening complex fluid—A surfactant model system
作者:
Yuntao Hu,
S. Q. Wang,
A. M. Jamieson,
期刊:
Journal of Rheology
(AIP Available online 1993)
卷期:
Volume 37,
issue 3
页码: 531-546
ISSN:0148-6055
年代: 1993
DOI:10.1122/1.550458
出版商: The Society of Rheology
关键词: Shear thickening;Birefringence;Micellar fluids, rheology of;Rheological measurements, transient;Surfactants, rheology of;SHEAR PROPERTIES;BIREFRINGENCE;TRANSIENTS;SURFACTANTS;MICELLAR SYSTEMS;CONCENTRATION RATIO;VISCOELASTICITY;RELAXATION TIME;SOLUTIONS
数据来源: AIP
摘要:
A common surfactant solution system is investigated to demonstrate the characteristic and generic features observed in shear‐thickening self‐assembling fluids. Rheological and flow birefringence measurements on the aqueous CTAB/sodium‐salicylate solutions disclose a number of unusual flow behaviors under different flow conditions. All solutions with concentrations ranging from 0.5 to 5 mM exhibit shear thickening above certain critical shear rates, accompanied by an increase in flow birefringence over a range of temperature fromT=14 to 36 °C. An extraordinarily long induction period, which is found to be inversely proportional to the applied shear rate, precedes the establishment of the shear‐thickening state. This dynamic state is highly flow birefringent, strongly nonlinear viscoelastic and possesses long relaxation times. We deduce that shear‐induced coagulation results in self‐assembling of surfactant molecules to form new micelles which are of exceedingly large sizes and which can survive against thermal disturbance for a long time.
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