Water sodium oleate

If the third substance dissolves in both liquids (and the solubility in each of the liquids is of the same order), the mutual solubility of the liquids will be increased and an upper C.S.T. will be lowered, as is the case when succinic acid or sodium oleate is added to the phenol - water system. A 0 083 molar solution of sodium oleate lowers the C.S.T. by 56 -7° this large effect has been applied industrially in the preparation of the disinfectant sold under the name of Lysol. Mixtures of tar acids (phenol cresols) do not mix completely with water at the ordinary temperature, but the addition of a small amount of soap ( = sodium oleate) lowers the miscibility temperature so that Lysol exists as a clear liquid at the ordinary temperature. 

X 10 M sodium oleate 1.5 X 10 M sodium oleate 10 M sodium oleate, pH = 8.1 10 Af potassium ethyl xanthate water... 

Fig. 16. Two-hquid flotation flow sheet (39). The original ROM is kaolin (white clay) that contains 11% impurity in the form of mica, anatase, and siUca. Treatment produces high purity kaolin and a Ti02-rich fraction. A, Kaolin stockpile D, dispersant (sodium siUcate plus alkah) W, water K, kerosene C, collector (sodium oleate) RK, recycled kerosene S, screen M, inline mixer SPR, separator CFG, centrifuge P, product and T, to waste.

In a study of the adsorption of soap and several synthetic surfactants on a variety of textile fibers, it was found that cotton and nylon adsorbed less surfactant than wool under comparable conditions (59). Among the various surfactants, the cationic types were adsorbed to the greatest extent, whereas nonionic types were adsorbed least. The adsorption of nonionic surfactants decreased with increasing length of the polyoxyethylene chain. When soaps were adsorbed, the fatty acid and the aLkaU behaved more or less independently just as they did when adsorbed on carbon. The adsorption of sodium oleate by cotton has been shown independently to result in the deposition of acid soap (a composition intermediate between the free fatty acid and the sodium salt), if no heavy-metal ions are present in the system (60). In hard water, the adsorbate has large proportions of lime soap. 

This test measures the minimum lime soap dispersant requirement (LSDR) (in g) which keeps 100 g of sodium oleate from precipitating in hard water (333 ppm CaC03). Although this is a convenient laboratory test, it bears little relation to an real in-use situation. 

As the interfacial tension is directly related to the concentration of surfactant molecules at the interface [46], the rhythmic changes in the interfacial tension suggest that the concentration of surfactant, sodium oleate in Figure 22A and DPPE in Figure 22B, at the oil/water interface changes repeatedly between high and low values. 

A 100-ml standard apparatus (round-bottomed flask, several inlets for stirrer, reflux condenser, nitrogen flux or vaccum,thermometer, heating bath) is evacuated and filled with nitrogen three times.The following solutions are prepared a) 500 mg of sodium oleate (or sodium dodecyl sulfate) in 16 ml of degassed water b) 125 mg (0.32 mmol)... 

These figures are in approximate agreement with values calculated -with the aid of the Freundlich adsorption isotherm (see p. 134) but no definite conclusions may be drawn from them since the actual area of liquid-liquid interface in all probability was variable being dependent on the amount of emulsifying agent present. More recently the quantity of various soaps required to form a stable emulsion of kerosene in water has been determined by Grifiin (J.A.C.8. XLV. 1648, 1923) for sodium oleate, potassium stearate and potassium palmitate and by der Meulen and Riemann ibid. XLVI. 876, 1924) for sodium ricinoleate. 

Bai [2] performed similar drop dissolution experiments with sodium oleate (NaOl) and Ci2(EO)4. For drops initially containing 7 and lOwt. % NaOl (particle size < 38 jim) the behavior was similar to that described above for drops having 8 wt. % SDS. However for drops with 15 and 17 wt. % NaOl dissolution was faster—comparable to that of the pure nonionics—and neither a surfactant-rich liquid immiscible with water nor emulsification was seen. Instead a concentrated liquid crystalline phase transformed directly into a micellar solution, as seen for the pure nonionics and nonionic mixtures well below their cloud points. 

Each gram of Plexion (sodium sulfacetamide 10% and sulfur 5%) cleanser contains 100 mg sodium sulfacetamide and 50 mg sulfur in a cleanser base containing water, sodium methyl oleyltaurate, sodium cocoyl isethionate, disodium oleamido MEA sulfosuccinate, cetyl alcohol, glyceryl stearate and PEG-100 stearate, stearyl alcohol, PEG-55 propylene glycol oleate, magnesium aluminum silicate, methylparaben, disodium EDTA, butylated hydroxytoluene, sodium thiosulfate, fragrance, xanthan gum, and propylparaben. Each gram of Plexion (sodium... 

A stiff emulsion is obtained consisting of 99 cc. of benzene, emulsified in 1 cc. of water, by about 0.05 per cent (by weight) of sodium oleate. If less than about 80 per cent (by volume) of benzene is used, the emulsion will not be homogeneous but will consist of a lower watery layer on which floats a creamy emulsion. 

If a solution of magnesium oleate is used instead of sodium oleate (soluble in oil but not in water), the oil becomes the external phase, and the water the internal. 

In a flask of about 150 cc. capacity, put 5 cc. of concentrated magnesium oleate solution, 5 cc. of benzene, 9 cc. of water, and 1 cc. of 1 per cent sodium oleate. Shake vigorously and at intervals of about 1 min. interrupt the shaking and add 2-cc. portions of water until a total of 20 cc. has been added. It is not practicable to go above 96 per cent of water, and emulsions containing about 75 per cent are more satisfactory. 

For this water concentration, the micellar region for the bile salt mixture is large for all oleyl compounds except oleic acid. Oleic acid is distinguished from the other compounds in that it does not form a lyotropic liquid crystalline phase spontaneously in water and, similarly, is present as oil droplets in bile salt solution when its micellar solubility is exceeded. Figure 1 shows also that the micellar area of an equimolar mixture of monoolein and sodium oleate is considerably greater than that of an equimolar mixture of monoolein and oleic acid, indicating that fatty acid ionization also enhances micellar solubility when monoolein is present. The equimolar mixture of sodium oleate and oleic acid has a micellar area similar in size to that of monoolein, as does the equimolar combination of all three compounds. 

Oleic Acid, Sodium Oleate, and Monoolein Mixtures in Saline. Four major regions are distinguishable according to the degree and nature of the interaction of the component(s) with water. 

Interaction with water, and dispersion into large aggregates. In samples containing appreciable sodium oleate, a turbid dispersion was present. Microscopically, this phase contained isotropic oil droplets, and the phase should represent emulsified fatty acid and monoglyceride droplets stabilized by acid soap. Unfortunately, x-ray diffraction facilities were not available to characterize this phase properly. 

Oleic acid may be obtained from glycerol trioleate, present in many liquid vegetable and animal nondrying oils, such as olive, cottonseed, lard, by hydrolysis. The crude oleic acid after separation of the water solution of glycerol is cooled to fractionally crystallize the stearic and palmitic acids, which are then separated by filtration, and fractional distillation under diminished pressure. Oleic acid reacts with lead oxide to form lead oleate, which is soluble in ether, whereas lead stearate or palmitaie is insoluble, prom lead oleate oleic add may be obtained by treatment with IL 5 (lead sulfide, insoluble solid, formed). With sodium oleate, a soap is formed. Most soaps are mixtures of sodium stearate, palmitate. and oleate. 

A nonpolar solubilizate such as hexane penetrates deeply into such a micelle, and is held in the nonpolar interior hydrocarbon environment, while a solubilizate such as an alcohol, which has both polar and nonpolar ends, usually penetrates less, with its polar end at or near the polar surface of the micelle. The vapor pressure of hexane in aqueous solution is diminished by the presence of sodium oleate m a manner analogous to that cited above for systems in nonpolar solvents. A 5% aqueous solution of potassium oleate dissolves more than twice the volume of propylene at a given pressure than does pure water. Dnnethylaminoazobenzene, a water-insoluble dye, is solubilized to the extent of 125 mg per liter by a 0.05 M aqueous solution of potassium myristate. Bile salts solubilize fatty acids, and this fact is considered important physiologically. Cetyl pyridinium chloride, a cationic salt, is also a solubilizing agent, and 100 ml of its A/10 solution solubilizes about 1 g of methyl ethyl-butyl either m aqueous solution. 

Figure 8. Temperature versus pressure phase diagram of a micellar solution of sodium oleate, 13 wt % in water. (Adapted from ref. 19).

Soluble substances like iodine also act as emulsifiers, in the case of ether/water emulsions. Some mixed stabilising agents also act as emulsifiers, e.g., ethyl alcohol and lycopodium powder, acetic acid and lamp black, clay and sodium oleate etc. 

Thioridazine, U.S.P. was obtained at Sandoz Pharmaceuticals Corporation, East Hanover, NJ. Sodium oleate (Purified Grade) was obtained from Fisher Scientific Company, Springfield, NJ. Polyvinyl alcohol (Type III, Hot Water Soluble, P 1763) was obtained from Sigma Chemical Company, St. Louis, MO. Poly(L-lactide) was prepared by Sandoz Ltd. (Basle, Switzerland) and poly(DL-lactide) by Battelle Columbus Laboratories (Columbus, OH). Other materials were of reagent grade unless otherwise specified. 

A solution of 1.0 g of thioridazine free base and 1.0 g of poly(DL-lactide) or poly(L-lactide) in 10 mL of methylene chloride was emulsified with 100 mL of an aqueous solution containing 0.4 g of sodium oleate or polyvinyl alcohol and 0-15 mL of 0.1 N NaOH (0-0.14 mole NaOH/mole lactic acid). After the emulsion was magnetically stirred for 10-15 minutes, the organic solvent was removed by rotary evaporation, 150 rpm, 375 mm Hg, at 40°C for 2 hours. The product was filtered, washed with water and vacuum dried at 30°C. 

The solvent evaporation microencapsulation process using sodium oleate as the emulsifier produced microspheres in high yields (75-95%), essentially free of agglomeration (1). Drugs with low solubility in water (0.02 mg/ml or less) e.g. thioridazine, were incorporated with 80-99% efficiency. Core loadings up to 60% were attained along with prolonged in vitro release. 

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). 

A stratification phenomenon in foam films from sodium oleate aqueous solutions has been described by Johonnott [314] and Perrin [318] in the beginning of the century. The stepwise thinning has been studied by many authors [e.g. 235,345], It became evident that this phenomenon is universal and has been observed also in emulsion films [346,347], asymmetric films of the air-water/oil type [348], films from latex suspensions [349] and liquid crystalline films [350],... 

Which of the surfactants in Problem 5 will be good for the dispersion of Ti02 in water Why (Answer sodium oleate)... 

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