Effect of Chemical Structure on Viscoelasticity and Extensional Viscosity of Drag-Reducing Cationic Surfactant Solutions

Abstract

Drag reduction, shear and extensional rheometry, and cryogenic transmission electron microscopy (cryo-TEM) were used to study aqueous solutions of one cationic surfactant, Arquad 16-50 (5 mM), with three isomeric counterions, 2-, 3-, or 4-Cl-benzoate at 12.5 mM. Each isomer showed different types of rheological and drag reduction behavior and different micellar structures. The 4-Cl system showed good drag reduction, high apparent extensional viscosity, and a thread-like micellar network, while the 2-Cl system showed no drag reduction, low apparent extensional viscosity, and only spherical micelles. The 3-Cl system was drag reducing and had high extensional viscosities at 30 °C. However, at 20 °C, the 3-Cl solution precipitated at high shear or extensional rates, leading to loss of drag reduction and low apparent extensional viscosity. The 3-Cl at 20 °C showed threadlike structures in some pictures and vesicles in others, presumably because of variations in the level of shear the samples were subjected to during sample preparation. The differences in behavior are explained by the position of the chlorine group on the benzoate ring. The hydrophobic chlorine in the 2-Cl system must reside in an unfavorable position in the aqueous phase and hence only spherical micelles are formed, which leads to no drag reduction and very low apparent extensional viscosity. The chlorine groups in the 3-Cl and 4-Cl counterions reside in the nonpolar hydrocarbon core of the micelles and, hence, stable elongated micelles can form. A schematic micellar phase diagram is proposed to summarize the transformations of surfactant molecular aggregates at different temperatures and external forces.

Elongational deformation of wormlike micellar solutions

“…Early investigations were based on opposed jet experiments ; Lu et al (1998);Prud'homme and Warr (1994); Walker et al (1996); Chen and Warr (1997)], four-roll mill experiments [Kato et al (2002); Kato et al (2004); Kato et al (2006)], entrance flow [Okawara et al (2008); Okawara et al (2009)], two-dimensional squeeze flow [Takahashi and Sakata (2001)], and flow through porous media experiments [Muller et al (2004)] showing an elongational hardening (increase of elongational viscosity with increasing elongation rate) of WLM solutions which is attributed to strong alignment of the micelles in flow direction. However, all these experiments were not purely extensional or had an unknown preshear history.…”

“…A fundamental understanding of material properties as well as the ability to predict changes that occur within the material during processing is extremely important for industrial application. Investigations so far mainly focused on the shear-banding phenomenon [Britton and Callaghan (1997); Britton and Callaghan (1999); Haward and McKinley (2012); Fischer and Challaghan (2001); Salmon et al (2003)], shear-thickening even in dilute solutions [Hu and Matthys (1995); Cappelaere et al (1994); Hartmann and Cressely (1997a); Hartmann and Cressely (1997b); Hartmann and Cressely (1997c); Cressely and Hartmann (1998); Hartmann and Cressely (1998); Wheeler et al (1998); Hu et al (1998); Nowak (2001); Berret and Serero (2001); Azzouzi et al (2005); Vasudevan et al (2008)] and the corresponding shear-induced structure (SIS) [Wheeler et al (1996); Kadoma et al (1997); Ouchi et al (2006a); Ouchi et al (2006b)] using different techniques such as turbidity [Yamamoto and Taniguchi (2012); Schubert et al (2004); Lerouge et al (2008); Herle et al (2005)], flow birefringence [Dehmoune et al (2007); Berret et al (2002); Wunderlich et al (1987); Oda et al (1997); Ouchi et al (2006b)], light scattering [Liu and Pine (1996); Boltenhagen et al (1997)], cryo transmission electron microscopy (cryo-TEM) [Oda et al (1997); Lu et al (1998)], particle image velocimetry …”

Effect of Mixing Modes on Chemiluminescent Detection of Epinephrine with Lucigenin by an FIA System Fabricated on a Microchip

“…Cationic surfactants are known to be effective as a drag reducer. 20 Therefore, the diffusion efficiency could be reduced in the presence of CTAOH, thus resulting in a decrease in the CL intensity. On the other hand, the noise level in the blank solution, which contained no EP, decreased remarkably in the presence of CTAOH.…”

A Dual Mechanism of the Drag Reduction by Rigid Polymers and Cationic Surfactant: Complex and Nanofluids of Xanthan Gum and Hexadecyl Trimethyl Ammonium Chloride

“…Another set of material are the surfactants which have been investigated by many authors [8-11. ], they offer an advantage of self-repair through micelles formation after degradation [12][13][14], but are less effective when compared to the polymers. Few other materials which have been investigated as drag reduction agents are fibers [15] bubbles [16] solid particles etc.…”