1611 Influence of shear rate history on occurrence of shear-induced structure in wormlike micelles solutions

2010 ◽  
Vol 2010 (0) ◽  
pp. 477-478
Author(s):  
Shogo CHIBA ◽  
Ryoji FUJIWARA ◽  
Masatoshi Ito ◽  
Tsutomu TAKAHASHI
Keyword(s):  
Shear Rate ◽  
Wormlike Micelles ◽  
Shear Induced Structure ◽  
Induced Structure

Effects of Shear on the Structures in a System of Small Rodlike Micelles

1994 ◽  
Vol 376 ◽  
Author(s):  
Paul D. Butler ◽  
L.J. Magid ◽  
William A. Hamilton ◽  
P.J. Kreke ◽  
Johnb. Hayter
Keyword(s):  
Shear Rate ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Supporting Electrolyte ◽  
Type Ii ◽  
Spherical Micelles ◽  
Shear Induced Structure ◽  
Induced Structure

ABSTRACTWe have used small angle neutron scattering (SANS) to study solutions of cetyltrimethylammonium 2,6-dichlorobenzoate (2,6) at rest and as a function of shear. These solutions are Newtonian, and up to a concentration of at least 100mM contain spherical micelles. Comparison with viscoelastic solutions of the closely related, and much studied, cetyltrimethylammonium 3,5-dichlorobenzoate (3,5) is made. While spheres are not expected to align under shear, a shear induced sphere to rod transition has been postulated for this system. In the results presented here, no shear induced sphere to rod transition was observed even at the highest accessible shear rate. Addition of sufficient supporting electrolyte (up to 1M NaCl) does cause such a transition in the quiescent solution. Hoffmann et al. have seen what they refer to as the formation of a shear induced structure (SIS or type II micelles) on similar systems where short rods form in the absence of supporting electrolyte. Shearing of the salted system produces rapid though not spectacular alignment, with no evidence of a SIS forming.

Influence of Shear Rate History on Generation of Shear-Induced Structure of Wormlike Micelles Solutions

2011 ◽  
Author(s):  
Shogo Chiba ◽  
Masatoshi Ito ◽  
Shuji Fujii ◽  
Tsutomu Takahashi
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Shear Flow ◽  
Wormlike Micelles ◽  
Acceleration Rate ◽  
History Of ◽  
The Moment ◽  
Evolution Behavior ◽  
The Relationship ◽  
Shear Induced Structure

The influence of the history of the shear rate on generation of shear hardening phenomenon of wormlike micelles aqueous solutions was investigated. An accelerated shear flow was applied to change the shear rate history and the influence of an acceleration rate on the time evolution behavior of the shear stress was observed. The relationship between the strain and the shear stress is given by one curve that is independent of a history of shear rate if the shear rate or the accelerated shear coefficient is higher than a certain critical value. A very high shear rate flow can be caused without the shear hardening by using the slowly accelerated shear flow but the SIS is generated if the shear rate in the moment exceeds the critical shear rate of the SIS formation.

Direct Evidence of the Shear-Induced Structure of Wormlike Micelles:  Gemini Surfactant 12−2−12

Langmuir ◽  
1997 ◽  
Vol 13 (24) ◽  
pp. 6407-6412 ◽  
Author(s):  
R. Oda ◽  
P. Panizza ◽  
M. Schmutz ◽  
F. Lequeux
Keyword(s):  
Gemini Surfactant ◽  
Direct Evidence ◽  
Wormlike Micelles ◽  
Shear Induced Structure ◽  
Induced Structure

Effect of Structures on Rheology in a Model Magnetorheological Fluid

1999 ◽  
Vol 13 (14n16) ◽  
pp. 2044-2051 ◽  
Author(s):  
Yun Zhu ◽  
Michael McNeary ◽  
Neal Breslin ◽  
Jing Liu
Keyword(s):  
Magnetic Field ◽  
Shear Rate ◽  
Yield Stress ◽  
Structural Transition ◽  
Magnetorheological Fluid ◽  
Structure Dependence ◽  
Dynamic Yield ◽  
Shear Induced Structure ◽  
Induced Structure ◽  
The Magnetic Field

The structure dependence of rheology on a model magnetorheological fluid is investigated experimentally. We find that the column-dominated structure formed under slow ramping of the magnetic field has higher dynamic yield stress than the "bent-wall" dominated structure formed under the fast ramping field. The measurement of the shear rate loop under fast ramping shows an abnormal rheological hysteresis. It indicates a shear assisted structural transition from the "bent-wall" dominated structure to a more stable structure. A possible shear-induced structure with circular stripes is suggested.

scholarly journals Rheological properties of hydroxypropylmethyl cellulose/sodium dodecylsulfate mixtures

2014 ◽  
Vol 79 (4) ◽  
pp. 457-468 ◽  
Author(s):  
Jaroslav Katona ◽  
Sandra Njaradi ◽  
Verica Sovilj ◽  
Lidija Petrovic ◽  
Brankica Marceta ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Sodium Dodecylsulfate ◽  
Shear Thinning ◽  
Cellulose Ether ◽  
Flow Profile ◽  
Hydroxypropylmethyl Cellulose ◽  
Shear Rates ◽  
Newtonian Liquids ◽  
Shear Induced Structure ◽  
Induced Structure

Rheological properties of mixtures of hydroxypropylmethyl cellulose (HPMC), a nonionic associative cellulose ether, and sodium dodecylsulfate (SDS), an anionic surfactant, were investigated by viscosity measurements performed at different shear rates (0.1-6000 s-1). HPMC/SDS mixtures containing different concentrations of SDS (CSDS=0.00-3.50 % w/w) and HPMC concentrations which corresponded to the overlap parameter c/c*=3, 6, and 12 were prepared. All HPMC/SDS mixtures were found to be shear-thinning when examined in a low-end-to mid-range of the applied shear rates. The degree of shear-thinning, n, and viscosity of the mixtures were influenced by composition of HPMC/SDS mixtures and HPMC-SDS complex formation. The changes in n ranged from values typical for highly shear thinning to almost perfectly Newtonian liquids, and were more pronounced as c/c* was increased from 3 to 6 and 12. A change in flow profile and a buildup of the first normal stress difference (N1) was observed in HPMC/SDS mixtures with c/c*=6 and 12 and CSDS 0.55-1.00 % and 0.55-2.50 %, respectively, when a critical shear rate, crit. was exceeded, suggesting that a shear-induced structure formation in the mixtures took place.

Modification of turbulence caused by cationic surfactant wormlike micellar structures in two-dimensional turbulent flow

2021 ◽  
Vol 933 ◽  
Author(s):  
Kengo Fukushima ◽  
Haruki Kishi ◽  
Hiroshi Suzuki ◽  
Ruri Hidema
Keyword(s):  
Turbulent Flow ◽  
Surfactant Solution ◽  
Turbulent Energy ◽  
Molar Ratio ◽  
Wormlike Micelles ◽  
Two Dimensional ◽  
Turbulence Statistics ◽  
Image Velocimetry ◽  
Set Up ◽  
Induced Structure

An experimental study is performed to investigate the effects of the extensional rheological properties of drag-reducing wormlike micellar solutions on the vortex deformation and turbulence statistics in two-dimensional (2-D) turbulent flow. A self-standing 2-D turbulent flow was used as the experimental set-up, and the flow was observed through interference pattern monitoring and particle image velocimetry. Vortex shedding and turbulence statistics in the flow were affected by the formation of wormlike micelles and were enhanced by increasing the molar ratio of the counter-ion supplier to the surfactant, ξ, or by applying extensional stresses to the solution. In the 2-D turbulent flow, extensional and shear rates were applied to the fluids around a comb of equally spaced cylinders. This induced the formation of a structure made of wormlike micelles just behind the cylinder. The flow-induced structure influenced the velocity fields around the comb and the turbulence statistics. A characteristic increase in turbulent energy was observed, which decreased slowly downstream. The results implied that the characteristic modification of the 2-D turbulent flow of the drag-reducing surfactant solution was affected by the formation and slow relaxation of the flow-induced structure. The relaxation process of the flow-induced structure made of wormlike micelles was very different from that of the polymers.

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