Potassium hexadecanoate

Micelles are approximately spherical aggregates of surfactant molecules with their nonpolar tails in the interior and their hydrophilic ends oriented towards the aqueous medium. They are some 50-100 A in diameter. The bulk concentration of surfactant is usually around 0.1 M and this corresponds to approximately I o micelles per milliliter of aqueous phase, since there are typically about 50-100 emulsifier molecules per micelle. The apparent water solubility of organic molecules is enhanced by micellar surfactants, because the organic molecules are absorbed into the micelle interiors. The extent of this solubilization of organic molecules depends on the surfactant type and concentration, the nature of the solubilized organic substance, and the concentration of electrolytes in the aqueous phase. As an example, there will be about an equal number of styrene molecules and potassium hexadecanoate (palmitate) molecules in a micelle of the latter material. In this case about half the volume of the micelle interior is occupied by solubilized monomer, and the concentration of styrene is approximately 4.5 M at this site. Thus radical polymerization starts very rapidly in the interior of a micelle once it is initiated there. 

One of the important properties of surfactants that is directly related to micelle formation is solubilization. Solubilization may be defined as the spontaneous dissolving of a substance (solid, liquid, or gas) by reversible interaction with the micelles of a surfactant in a solvent to form a thermodynamically stable isotropic solution with reduced thermodynamic activity of the solubilized material. Although both solvent-soluble and solvent-insoluble materials may be dissolved by the solubilization mechanism, the importance of the phenomenon from the practical point of view is that it makes possible the dissolving of substances in solvents in which they are normally insoluble. For example, although ethylbenzene is normally insoluble in water, almost 5 g of it may be dissolved in 100 mL of a 0.3 M aqueous solution of potassium hexadecanoate to yield a clear solution. 

Alternatively, the TTF or the dithiapyrene was lithiated, treated with elemental sulfur, and allowed to react with the potassium salts of co-bromo- or 0)-iodo-undecanoic acid or -hexadecanoic acid (Fig. 3, compounds 4, 5,6, 7, and 8). 

Hexadecanoic acid-CD-triphenylphosphonium bromide (5 mmol) was dissolved in tetrahydrofuran (THF) containing 10% HMPTA, and treated with two equivalents of potassium tert-butoxide at -10 C. One equivalent of TTF-carboxaldehyde, dissolved in THF, was added, and the mixture was stirred for 0.5 hour diethyl ether was added, and the product filtered off, and purified through acidic water-ether extraction, column chromatography (silica/ethyl acetate), followed by recrystallization from methanol, to provide ca. 500 mg of 3. 

Hexadecanoic acid, monoester with 1,2,3-propanetriol. See Glyceryl palmitate Hexadecanoic acid, potassium salt. See Potassium palmitate... 

Hexadecanoic acid, potassium sait See Potassium paimitate... 

Hexadecanol, phosphate, potassium saH. See Potassium cetyl phosphate (3-Hexadecanoyloxy-2-hydroxy-propyl) hexadecanoate. See Glyceryl dipalmi-tate... 

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