Surfactant hydroxide emulsions

One can observe similar effects If the same surfactants are used as emulsifying agents. Table ill shows results obtained in benzene - aqueous two molar sodium hydroxide emulsions using different surfactants. AgAin It can be seen that the film forming cationic surfactant causes marked Increases In yields. 

Water-in-oil macroemulsions have been proposed as a method for producing viscous drive fluids that can maintain effective mobility control while displacing moderately viscous oils. For example, the use of water-in-oil and oil-in-water macroemulsions have been evaluated as drive fluids to improve oil recovery of viscous oils. Such emulsions have been created by addition of sodium hydroxide to acidic crude oils from Canada and Venezuela. In this study, the emulsions were stabilized by soap films created by saponification of acidic hydrocarbon components in the crude oil by sodium hydroxide. These soap films reduced the oil/water interfacial tension, acting as surfactants to stabilize the water-in-oil emulsion. It is well known, therefore, that the stability of such emulsions substantially depends on the use of sodium hydroxide (i.e., caustic) for producing a soap film to reduce the oil/water interfacial tension. 

Epolene E-43 wax nonionic emulsion (40%) Epolene E-43 wax Igepal CO-630 surfactant Potassium hydroxide (86%)... 

Soap - [SOAP] (Vol 22) -centrifugal separation of [SEPARATION - CENTRIFUGAL SEPARATION] (Vol21) -disinfectant and antiseptic m (DISINFECTANTS AND ANTISEPTICS] (Vol 8) -m emulsion polymerization [STYRENE-BUTADIENE RUBBER] (Vol 22) -nut oils m [NUTS] (Vol 17) -potassium hydroxide mmfg of [POTASSIUM COMPOUNDS] (Vol 19) -sampling standards for [SAMPLING] (Vol 21) -as synthetic surfactant [SURFACTANTS] (Vol 23)... 

Anionic surfactants are negatively charged in an aqueous solution (i.e., -COO-, -OSOj), and widely used because of their cost and performance. Sodium lauryl sulfate, the main component of which is sodium dodecyl sulfate, is highly soluble in water and commonly used to form oil-in-water (O/W) emulsions. Reacting an alkali hydroxide with a fatty acid (e.g., oleic acid) can produce alkali metal soaps (e.g., sodium oleate). Careful attention must be paid to the pH of the dispersion medium and the presence of multivalent metals (see Section 4.2.5). Alkali earth metal soaps (e.g., calcium oleate) produce stable water-in-oil (W/O) emulsions because of their low water solubility and are produced by reacting oleic acid with calcium hydroxide. Triethanolamine stearate produces stable O/W emulsions in situ by reacting triethanolamine in aqueous solution with melted stearic acid at approximately 65°C (e.g., vanishing cream). 

In another interesting development, Yei et al. [124] prepared POSS-polystyrene/clay nanocomposites using an emulsion polymerization technique. The emulsion polymerization for both the virgin polystyrene and the nano composite started with stirring a suspension of clay in deionized water for 4h at room temperature. A solution of surfactant ammonium salt of cetylpyridinium chloride or POSS was added and the mixture was stirred for another 4 h. Potassium hydroxide and sodium dodecyl sulphate were added into the solution and the temperature was then raised to 50 °C. Styrene monomer and potassium persulfate were later on added slowly to the flask. Polymerization was performed at 50 °C for 8 h. After cooling, 2.5% aqueous aluminium sulphate was added to the polymerized emulsion, followed by dilute hydrochloric acid, with stirring. Finally, acetone was added to break down the emulsion completely. The polymer was washed several times with methanol and distilled water and then dried overnight in a vacuum oven at 80 °C. The obtained nanocomposite was reported to be exfoliated at up to a 3 wt % content of pristine clay relative to the amount of polystyrene. 

Droplet size depends on a number of factors such as the type of oil, brine composition, interfacial properties of the oil-water system, surface-active agents present (added or naturally occurring), flow velocity, and nature of porous material. For the study of OAV emulsions, McAuliffe (9) varied emulsion droplet sizes and size distributions by increasing the sodium hydroxide concentration in the aqueous phase, as shown in Figure 10. Higher NaOH concentration neutralizes more of the surface-active acids in the crude oil and produces an emulsion that has droplets of smaller diameters and is also more stable. Emulsion droplet size distribution can also be varied by varying the concentration of a surfactant added to the crude oil, as shown in Figure 11. 

Most emulsion polymerization is based on free-radical reactions, involving monomers (e.g., styrene, butadiene, vinyl acetate, vinyl chloride, methacrylic acid, methyl methacrylate, acrylic acid, etc.), surfactant (sodium dodecyl diphenyloxide disulfonate), initiator (potassium persulfate), water (18.2MQ/cm), and other chemicals and reagents such as sodium hydrogen carbonate, toluene, eluent solution, sodium chloride, and sodium hydroxide. 

Alkaline flooding is also called caustic flooding. Alkalis used for in situ formation of surfactants include sodium hydroxide, sodium carbonate, sodium orthosilicate, sodium tripolyphosphate, sodium metaborate, ammonium hydroxide, and ammonium carbonate. In the past, the first two were used most often. However, owing to the emulsion and scaling problems observed in Chinese field applications, the tendency now is not to use sodium hydroxide. The dissociation of an alkali results in high pH. For example, NaOH dissociates to yield OH" ... 

Inorganic substances Uke small metal clusters, metal oxides etc. may also be deposited on the surface of single or bundled carbon nanotubes. It is possible, for instance, to decorate multiwalled nanotubes with nanoparticulate oxides of zinc or magnesium. To this end, a surfactant-mediated dispersion of MWNT is solubilized in cyclohexane with Triton X-114 as a surface-active agent to obtain a water/ oil emulsion. Aqueous solutions of the respective metal acetates are added afterward and are then found in the aqueous portion of the emulsion. Subsequently increasing the pH value to about 9.5 causes a precipitation of the metal hydroxides that deposit on the nanotube surface in the shape of hollow spheres. Final calcination at 450 °C transforms these hollow particles into the crystalhne metal oxides. Particles measuring about 5 nm or 30-40 nm have been observed for ZnO or MgO, respectively (Figure 3.84b). 

Because of the formation of emulsions at phase boundaries for APE surfactants, EEE is limited to the degradation products APs, alkylphenol monoethoxylate to triethoxylate (APE(l-3)) and alkylphenol ethoxy carboxylate (APEC). Dichloromethane and hexane are the solvents commonly used in the extraction of APs and APE(l-3) from liquid samples.For phenolic compounds including BPA, OP, and NP, water samples are often acidified to pH < 4 with hydrochloric acid. Acidification of water samples suppresses the dissociation of phenols and prevents the ionization of the analytes, which increased the efficiency of the extraction. Del Olmo et al. " studied the effect of pH on extraction of BPA using sodium hydroxide and hydrochloric acid for adjustment. The result obtained showed that the extraction efficiency remains constant for pH values lower than 6.5, decreasing sharply for higher values. This behavior agrees with the weak acid nature of BPA. 

Several alkaline chemicals have been employed for various aspects of enhanced oil recovery. Two of the most favorable alkaline chemicals tested and used in tertiary oil recovery are sodium orthosilicate and sodium hydroxide. Comparing their characteristics, both chemicals react with acids in crude oil to form surfactants, precipitate hardness ions and change rock surface wettability. One difference between the two chemicals is that the interfacial properties for sodium orthosilicate systems are less affected by hardness ions (13), hence slightly lower interfacial tensions would occur. Lower Interfacial tensions can aid in in-situ emulsion formation. 

Beattie, J.K., DJerdJev, A.M. The pristine oil/water interface surfactant-free hydroxide-charged emulsions. Angew. Chem. Int. Ed. Engl. 43, 3568-3571 (2004)... 

Synonyms Amides, palm oil, N-(2-hydroxypropyl)- N-(2-Hydroxypropyl) palm oil acid amide Monoisopropanolamine palm oil acid amide Palm oil acid amide, N-(2-hydroxypropyl)- Palm oil acid monoisopropanolamide Definition Mixt. of isopropanolamides of the fatty acids derived from palm oil Formula RCONHCH2CH3CHOH where RCO- rep. fatty acids derived from palm oil Uses Emulsifier, emulsion stabilizer, surfactant, vise, control agent in cosmetics Palmamidopropyl betaine Synonyms 1-Propanaminium, N-carboxymethyl-N,N-dimethyl-3-amino-, N-(palm-oil acyl) derive., hydroxides, inner salts Classification Zwitterion (inner salt)... 

Lu and Yeh [174] record an emulsion technique for the synthesis of ZnO. They dissolved zinc acetate in de-ionized water to obtain the aqueous phase, n-heptane was used as the continuous phase, in which a surfactant (Span 80) was added. The two phases in different proportions were mixed continuously for Ih for obtaining homogeneous emulsions. Ammonium hydroxide was added into the emulsions to cause precipitation of zinc. The precipitates were dried and calcined at 700 -1000°C/2 h, which yielded white powders of ZnO. The modal particle size was 0.080 pm, while the mean size was about 0.08-0.09 pm depending on experimental conditions. 

Alkaline inorganic chemicals such as sodium silicates, sodium hydroxides, sodium carbonate, and sodium phosphates have been added to injection fluids used in enhanced oil recovery systems. These chemicals can, in varying degrees, affect various rock and fluid parameters such as interfacial tension, interfacial viscosity, emulsion stability, rock wettability, hardness-ion content, ion-exchange capacity or equilibria, surfactant adsorption, phase equilibria, etc., in order to improve recovery efficiency for residual oil remaining after waterflooding. 

The data from these tests show that sodium orthosilicate is more effective than sodium hydroxide in recovering residual oil under the conditions studied, both for continuous flooding and when 0.5 PV of alkali was injected. The mechanisms through which sodium orthosilicate produced better recovery than sodium hydroxide in this system have not been completely elucidated. Reduction in interfacial tension is similar for both chemicals, so other factors must play a more important role. Somasundaran (26) has shown that sodium silicates are more effective than other alkaline chemicals in reducing surfactant adsorption on rock surfaces. Wasan (27,28) has indicated that there are differences in coalescence behavior and emulsion stability which favor sodium orthosilicate over sodium hydroxide. Further work is being done in this area in an attempt to define the limits of physically measurable parameters which can be used for screening potential alkaline flooding candidates. 

As with almost all other resin classes, work has been done to make alkyd resins for coatings that can be reduced with water. One approach that has been more extensively studied in Europe than in the United States is the use of alkyd emulsions (25,26). The emulsions are stabilized with surfactants and can be prepared with little, if any, volatile solvent. Some problems limit use of alkyd emulsions (27). Coatings prepared using alkyd emulsion loose dry time on storage because of absorption of cobalt drier on the surface of pigments and precipitation of cobalt hydroxide. Best results were obtained with a combination of cobalt neodecanoate... 

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