Drag-reduction effectiveness surfactants

Lin, Z. The effect of chemical structures of cationic surfactants or counterions on solution drag reduction effectiveness, rheology and micellar microstructure. Ph.D. dissertation. The Ohio State University, Columbus, OH, 2000. 

These earlier reports on drag reduction with surfactants utilized single surfactants and described the effects of electrolytes and temperature changes on their drag reducing abilities. Recent work by Florence and Puisieux and coworkers (12,13) has shown that a combination of an insoluble surfactant (C gH -(OCH2-CH2)2 11) solubilized by a soluble surfactant 10 forms much larger micelles than the latter... 

Recently, Inaba and co-workers (173) pointed out that it is possible to reduce the pumping power, to downsize the transport system, and to decrease the heat loss to environment by using surfactant water solution as a thermal energy transport medium. The environmental pollution caused by discarding the used surfactant solution has become a serious problem. It is required that the new additive have the same flow drag reduction effect as surfactant solution, and also that little environment load be used. They used pulp fiber as the new type of flow drag reduction additive in a circular pipe. The pulp fiber consists of a... 

Macromolecular substances such as synthetics (Sellin 1982 Berman 1978), biopolymers (Hoyt 1985), or surfactants (Shenoy) have proved to be effective flow improvers . Suspended fibers and solid particles (e.g., Metzner 1977,1976 McComb 1981), however, may also produce this effect. Small suspended particles in the air ( dust ) have been found to cause drag reductions of the same order of magnitude as polymers in liquids (Rossetti). 

Fig. 8 shows DR vs. of a typical DR cationic surfactant with counterion solution, Ci7H35N(CH3)3Cl/ 3,4-Cl-benzoate (5mM/12.5mM). Drag reduction reaches a maximum of 65%. In the effective temperature range (15-85°C), DR first increases with Arc until a critical Arc (critical wall shear stress) is reached above which it begins to lose its DR ability because of the... 

Anionic Surfactants Early studies by Savins [1967] showed that sodium oleate soaps with potassium hydroxide and potassium chloride in aqueous solution had good DR effectiveness. Increasing the concentration of KCl from 5% to 10% gave better drag reduction results. Unfortunately, the soaps precipitate and are ineffective as DRAs in the presence of calcium ions, which are present in most aqueous systems. Solutions of anionic surfactants such as SDS and SDBS are not drag reducing. Little research on anionics as DRAs has been carried out. 

Amine oxide zwitterionics are not strongly DR effective. At low temperatures oleyl dihydroxyethyl amine oxide (OHAO) shows weak drag reduction from 5 to 15°C. At high temperatures, behenyl dihydroxyethylamine oxide (BMAO) is weakly DR from 60 to 80°C. However, when 2-lauryl carboxymethyl hydroxyethyl imidazolium betaine was added to OHAO at a ratio of 1 to 1.5, at 15°C DR was increased from 55% to 70%. The surfactant also increased drag reduction from 10% to 88% at 80°C when added to BMAO [Nobuchika et al., 2000]. 

Zhang et al. [2005b] studied the effects of various percents of ethylene glycol in water (15,20, and 28%) on cationic surfactant solution properties. Using commercial cationics from Akzo Nobel (Ethoquad 012 and 013), they observed that the cosolvent reduced the upper temperature limit for drag reduction, maximum percent drag reduction, maximum critical wall shear stress, and relative shear viscosity. The formation of TLMs was hampered, but the addition of excess sodium salicylate promoted TLM... 

Chou, L. C., Christensen, R. N., and Zakin, J. L., The influence of chemical composition of quaternary ammonium salt cationic surfactants on their drag reducing effectiveness, in Drag Reduction in Fluid Flows, SeUin, R. H. J., and Moses, J. T., Eds., Ellis Horwood, Chichester, UK, 1989b, pp. 141-148. 

Horiuchi, T., Yoshii, T., Majima, T., Tamura, T., and Sugawara, H., Effect of alkyl chain length and number of 2-hydroxyethyl groups on drag reduction behaviors of quaternary ammonium salt-type cationic surfactant solutions, Nippon Kagaku Kaishi, 415-421 (2001b). 

Zhang, Y., Qi, Y, and Zakin, J. L., Headgroup effect on drag reduction and rheological properties of micellar solutions of quaternary ammonium surfactants, Rheol. Acta, 45, 42-58 (2005a). 

Aqueous solutions of complex soaps (1-3) are drag reducers, as are certain conventional soaps (4-6) and nonionic surfactants (7-11), and they do not have some of these deficiencies. They have the advantage of regaining their drag reducing effectiveness after subjection to high shear fields. The latter two are effective near their coacervation temperature or cloud point (upper consolute temperature). The addition of electrolyte lowers the cloud point and therefore the temperature at which effective drag reduction occurs. Cloud points can be adjusted to convenient temperatures in this manner. 

---