Surface tension sodium hydroxide

Soap. The reaction product of a fatty acid ester and a metal hydroxide, usually sodium hydroxide. Soap lowers the surface tension of water, permitting emulsification of soil-bearing fats if the soap is used for washing, of monomers in solution if the soap is used for emulsification in a polymerization process. 6 e saponification. 

Although solvent samples have been observed for approximately one year without any solids formation, work was completed to define a new solvent composition that was thermodynamically stable with respect to solids formation and to expand the operating temperature with respect to third-phase formation.109 Chemical and physical data as a function of solvent component concentrations were collected. The data included BC6 solubility cesium distribution ratio under extraction, scrub, and strip conditions flowsheet robustness temperature range of third-phase formation dispersion numbers for the solvent against waste simulant, scrub and strip acids, and sodium hydroxide wash solutions solvent density viscosity and surface and interfacial tension. These data were mapped against a set of predefined performance criteria. The composition of 0.007 M BC6, 0.75 M l-(2,2,3,3-tetrafluoropropoxy)-3-(4-.sw-butylphenoxy)-2-propanol, and 0.003 M TOA in the diluent Isopar L provided the best match between the measured properties and the performance criteria. 

The styrene (Polysciences) was washed with 10 aqueous sodium hydroxide to remove the inhibitor and vacuum-distilled under dry nitrogen the 1-pentanol (Fisher Scientific) was dried over potassium carbonate and vacuum-distilled the potassium persulfate (Fisher Scientific) was recrystallized twice from water the 2,2 -azobls(2-methyl butyro-nltrlle) (E. I. du Pont de Nemours) was recrystallized twice from methanol the sodium dodecyl sulfate (Henkel) was used as received its critical micelle concentration measured by surface tension was 5.2 mM. Dlstllled-delonlzed water was used in all experiments. 

Dynamic IFT arises from the reaction of acidic components in the crude oil to form petroleum soaps. Reaction of acidic surface-active materials in the crude oil with sodium hydroxide in the aqueous phase is assumed to occur rapidly at the interface, but desorption of these species is taken to be slower. This slower desorption leads to a maximum in the concentration of surface-active species at the interface at some point in time and hence an interfacial tension minimum. Subsequently, IFT increases as equilibrium is approached (58). 

Since sodium hydroxide is more than twice as dense as sodium, it would appear that its formation would have no effect on the reaction rate — i.e., it would sink to the bottom of the pocket, thereby exposing fresh sodium. Previous observations by the authors indicated that caustic formed during a reaction remained as a film over the sodium. The support of this film is presumed to be due to a surface tension phenomenon. 

G. G. and I. N. Longinescu calculated the sp. gr. of the soln. considered as a binary mixture. C. del Fresno, and D. Balarefi studied the mol. vol. R. Dubrisay measured the surface tension during the progressive neutralization of chromic acid soln. by soln. of sodium hydroxide, and by ammonia, and found that chromic acid differs from a strong dibasic acid, such as sulphuric acid, in exhibiting a constant surface tension only until the first acid function is neutralized, after which the surface tension decreases gradually but slightly until the second is neutralized. 

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. 

Marasperse lignosulfonates can produce stable emulsions. These emulsions are resistant to pH and eletrolyte contents. It has been observed that sodium hydroxide enhances the surface activity of aqueous lignosulfonate solutions, which in turn lowers the interfacial tension at the oil/water interface, thereby rendering the emulsions more stable. The emulsions stabilized by lignosulfonates are also resistant to mechanical agitations and to large temperature variations. 

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. 

The simplest class of anionic perfluoroalkanesulfonamides surfactants with the general structure RpS02NH M can be obtained by the reaction of suitable intermediates such as perfluoroalkanesulfonamides or N-alkylated perfluoroalkanesulfonamides with a base (e.g., sodium hydroxide, triethylamine, or propylamine) in a solvent (e.g., water or water-miscible organic solvents) at temperatures between 20 and 70°C (Scheme 18.2). Although these salts can be obtained from both unalkylated and monoalkylated sulfonamides, salts derived from unsubstituted sulfonamides are of particular interest and have been claimed to lower the surface tension of water to 20 dyn/cm at concentrations as low as 0.2 g/L. 

Amott method, to be preferentially oil-wet, RDI= —0.82. Laboratory work was undertaken to determine the feasibility of injecting alkaline solutions to improve oil recovery. These experiments were designed to produce surfactants in-situ. The surfactants would both lower the interfacial tension and react with the reservoir rock surface to modify the wettability of the porous media. The experimental work considered the injection of seawater and sodium hydroxide mixtures into cores. The experimental results show that the oil recovery was higher than 50% when the alkaline solution was injected. The conclusion was that surfactant produced by alkaline injection altered the rock wettability from oil-wet to intermediate-wet, increasing oU recovery. One precaution with alkaline flooding is that the range of reactions and the change in pH can cause unexpected variation in oil recovery if the reservoir and fluids are not well characterized. 

A Kriiss K6 tensiometer with a platinum du Noiiy ring was used during the surface tension measurements, and the experiments were performed at a temperature of 20 °C. Concentrated surfactant solutions were prepared, and the pH was adjusted with sodium hydroxide or hydrochloric acid. The samples were prepared by dilution with Milli-Q water, buffered to the appropriate pH. The sample volumes were approximately 13 ml and the surface area of the samples were ca 15.5 cm. The surface tension was measured directly after pouring the liquid into the sample vessel. The surface tension value for each sample was multiplied by the appropriate correction factor, according to Harkins and Jordan. [7] The cmc was found at the break point in the surface tension versus concentration plot. 

Patrov BV, Yurkinskii VP (2004) Surface tension and density of a sodium hydroxide melt. Russ J Appl Chem 77 2029-2930... 

The stability of perfluorinated anionic surfactants is also remarkable in alkali. Glockner et al. [79] found the surface tensions of perfluorinated anionic surfactants in saturated aqueous sodium hydroxide to be constant for at least 100 days (Table 4.11). Salts of perfluoroalkanoic, perfluoroalkanesulfonic, or perfluo-roalkenesulfonic acids survived an alkaline fusion [5 g KN03/LiN03 (35-65 mol%), 0.5 g NaOH, 0.05 g surfactant] for 2 h at 200°C, as indicated by the surface tensions of the aqueous solutions of the fusion mass. 

The liquid phase of most academic and industrial interest is water, which has a surface tension of 72-73 mN/m at 20°C. A 1% aqueous sodium hydroxide solution will have a slightly higher value of about 73 mN/m, while one of 10% will approach 78 iiiN/m. Relatively high concentrations of NaOH, or other electrolyte, are required to significantly increase the surface tension of water. The more normal result of dissolution of a material is to lower the surface tension of the liquid. In addition, the lowering effect is usually apparent at concentrations much lower than those required to raise the surface tension. 

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