Equilibrium and dynamic behavior of a system containing a mixture of anionic and nonionic surfactants

Mori, Fuyuhiko; Lim, JongChoo; Miller, Clarence A.

doi:10.1007/bfb0118249

Cited by 24 publications

(7 citation statements)

References 7 publications

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“…In addition to the effect of hydrocarbon chain branching discussed previously, the presence of an ethylene oxide and/or propoxylene oxide chain in such anionic surfactant systems seems to promote formation of a surfactant-rich liquid instead of lamellar phase. For instance, a straight-chain C 12-13 ethoxylated sulfate having three ethylene oxide groups exhibited formation of a second liquid phase at 30°C upon adding 12.5 wt% NaCl (Mori et al 1990). Similar behavior was seen for a 1:1 blend of a similar surfactant and a propoxylated sulfate having an iso-C 13 hydrophobe (Zhang 2006) (TC blend, see Table 1).…”

Section: Phase Behavior Of Oil-free Surfactant Solutionsmentioning

confidence: 97%

Favorable Attributes of Alkaline-Surfactant-Polymer Flooding

et al. 2008

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A laboratory study of the alkaline-surfactant-polymer (ASP) process was conducted. It was found from phase-behavior studies that for a given synthetic surfactant and crude oil containing naphthenic acids, optimal salinity depends only on the ratio of the moles of soap formed from the acids to the moles of synthetic surfactant present. Adsorption of anionic surfactants on carbonate surfaces is reduced substantially by sodium carbonate, but not by sodium hydroxide. The magnitude of the reduction with sodium carbonate decreases with increasing salinity.Particular attention was given to a surfactant blend of a propoxylated sulfate having a slightly branched C 16-17 hydrocarbon chain and an internal olefin sulfonate. In contrast to alkyl/aryl sulfonates previously considered for EOR, alkaline solutions of this blend containing neither alcohol nor oil were single-phase micellar solutions at all salinities up to approximately optimal salinity with representative oils. Phase behavior with a west Texas crude oil at ambient temperature in the absence of alcohol was unusual in that colloidal material, perhaps another microemulsion having a higher soap content, was dispersed in the lower-phase microemulsion. Low interfacial tensions existed with the excess oil phase only when this material was present in sufficient amount in the spinning-drop device. Some birefringence was observed near and above optimal conditions. While this phase behavior is somewhat different from the conventional Winsor phase sequence, overall solubilization of oil and brine for this system was high, leading to low interfacial tensions over a wide salinity range and to excellent oil recovery in both dolomite and silica sandpacks. The sandpack experiments were performed with surfactant concentrations as low as 0.2 wt% and at a salinity well below optimal for the injected surfactant. It was necessary that sufficient polymer be present to provide adequate mobility control, and that salinity be below the value at which phase separation occurred in the polymer/surfactant solution.A 1D simulator was developed to model the process. By calculating transport of soap formed from the crude oil and injected surfactant separately, it showed that injection below optimal salinity was successful because a gradient in local soap-to-surfactant ratio developed during the process. This gradient increases robustness of the process in a manner similar to that of a salinity gradient in a conventional surfactant process. Predictions of the simulator were in excellent agreement with the sandpack results.

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Section: Phase Behavior Of Oil-free Surfactant Solutionsmentioning

confidence: 97%

Favorable Attributes of Alkaline-Surfactant-Polymer Flooding

et al. 2008

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“…The combination of ionic surfactant and lipophilic poly(oxyethylene) type nonionic surfactant is considered to be a good candidate to produce microemulsions. Although the phase diagrams of water/ionic surfactant/nonionic surfactant/oil systems were reported, − the detail phase behavior of ionic-nonionic microemulsion systems has not been studied.…”

Section: Introductionmentioning

confidence: 99%

Formation of Microemulsions in Mixed Ionic−Nonionic Surfactant Systems

et al. 1998

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Phase behavior of a mixed surfactant, sodium dodecyl sulfate + lipophilic poly(oxyethylene) dodecyl ether, in a brine-decane system was investigated at a constant brine/decane weight ratio equal to 1. Solubilization capability of the mixed surfactant reaches its maximum and microemulsion is formed when the surfactant is changed from hydrophilic to lipophilic in a given system. In the present system, lamellar liquid crystal (LC) intrudes in the single-microemulsion region, and three-phase microemulsions are not formed. The mixing fraction of nonionic surfactant in the total surfactant in the midst of the LC present region increases with increasing oil content due to the high solubility of nonionic surfactant in oil. The partition of nonionic surfactant molecules between the oil and the bilayer in the LC phase is analyzed by using the geometrical relationship of the phase equilibria in the phase diagrams, taking into account the solubility. The monomeric solubility of nonionic surfactant in oil is much less than that of an ordinary cosurfactant like hexanol, and the mixing fraction of nonionic surfactant in the bilayer decreases with increasing salinity. The interlayer spacing of the midlamellar liquid crystal between the two microemulsion regions was measured by small-angle X-ray scattering. The average effective cross-sectional area per surfactant is about 0.37 nm2 and is unchanged upon dilution. It is considered that there is a strong attractive interaction between the ionic group and the nonionic hydrophilic moiety of surfactants.

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“…Figure 5a 9 , taken at times t = 24 and 30 s, respectively, show that the rollback mechanism takes place a second time on this high-interfacial-tension film. This second rollback in turn induces the remaining thin oil film to evolve into an oil droplet, as shown by Figure 5a 10 , which then undergoes a phase transition in Figure 5a 11 , and then finally detaches from the solid surface, as shown in Figure 5a 12 at t = 56 s. It can be concluded that at a high Brij 30 concentration of 20% w/w, the detergency mechanism occurs by both rollback and spontaneous emulsification. Figure 6 reveals the detergency mechanism for the case in which Brij 30 concentration in the droplet is 231.49 mM (10% w/w).…”

Section: Resultsmentioning

confidence: 95%

“…The soil can be directly solubilized into the surfactant micelles (4,5); alternatively, the soil may form an intermediate phase containing soil, surfactant, and water that is more readily removed than the original soil, for instance, by direct emulsification. A common intermediate phase involved in this mechanism is a lamellar liquid crystal (6)(7)(8)(9)(10)(11)(12). A review by Miller (13) discusses solubilization-emulsification mechanisms and illustrates the formation of microemulsions and lamellar liquid crystalline phases as intermediates (13).…”

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confidence: 99%

Surfactants and protocols to induce spontaneous emulsification and enhance detergency

López-Montilla

James

Crisalle

et al. 2005

J Surfact & Detergents

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In this study the presence of an oil-soluble nonionic surfactant, Brij 30 (polyoxyethylene-4 lauryl ether), in an oil stain, or its addition to the stain through an oil-based solution or water-based mixture is shown to enhance, to a great extent, the spontaneous removal of the stain from a polyester fabric by inducing rollback and spontaneous emulsification phenomena. These findings lead to potential applications of Brij 30 as laundry pre-spotters for enhancement of the removal of tough stains. The effect of three key factors, namely, the surfactant type, the surfactant concentration, and the surfactant application protocol, on the effectiveness of spontaneous detergency was analyzed via ultraviolet-visible spectroscopy. The test fabrics were soiled with a stain composed of mineral oil plus or-The results showed that all three factors were important for effective detergency. Brij 30 removed more than 80% w/w of the stain, whereas sodium dodecyl sulfate removed less than 24% w/w, and Brij 35 (polyoxyethylene-23 lauryl ether) was ineffective, removing less than 1% w/w. It was also observed that a low threshold concentration of Brij 30, approximately 0.2 mM, was required to spontaneously remove the oil stain, and that higher concentrations did not cause a significant enhancement of the effectiveness of soil removal. Brij 30 completed the detergency effect in less than 1 min, which may have beneficial implications regarding reduced energy consumption. Video microscopy studies revealed that at low Brij 30 surfactant concentrations, the mechanism for spontaneous oil removal proceeded predominantly via a rollback mechanism and that at higher concentrations, a spontaneous emulsification mechanism became progressively more important.Paper no. S1381 in JSD 8, 45-53 (January 2005). KEY WORDS: Brij 30, detergency, organic stain removal, rollback, spontaneous emulsification, spontaneous detergency, video microscopy. Abbreviations: Brij 30, polyoxyethylene-4 lauryl ether = C 12 H 25 (OCH 2 -CH 2 ) n OH, n ~ 4; Brij 35, polyoxyethylene-23 lauryl ether; HLB, hy-

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Equilibrium and dynamic behavior of a system containing a mixture of anionic and nonionic surfactants

Cited by 24 publications

References 7 publications

Favorable Attributes of Alkaline-Surfactant-Polymer Flooding

Favorable Attributes of Alkaline-Surfactant-Polymer Flooding

Formation of Microemulsions in Mixed Ionic−Nonionic Surfactant Systems

Surfactants and protocols to induce spontaneous emulsification and enhance detergency

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