Sodium dodecyl sulfate and other alkyl sulfates were treated by the method of polythermal conductometry to remove primary alcohols. The electrical conductivity polytherms were analyzed. The composition of the liquid and solid phases in equilibrium in the mixed solutions was determined. The method of the synthesis of chemical purity colloids of alkyl sulfates and other ionogenic micelle forming surfactants was suggested based on the optimal choice of crystallization temperature of the solutions.Modern scientifi c and high-technology areas (medicine, pharmacy, electronics, and nanotechnology) greatly need for high-purity surfactants (SAAs). One of the most common methods of the preparation of metallic nanoparticles uses surfactant micelles as unique nanoreactors responsible for the synthesis topochemistry and the size and morphology of the particles [1]. For preparing multimolecular layers, known as the Langmuir-Blodgett fi lms, the purity of SAAs is the particularly important parameter [2]. These nanosized planar structures arouse a wide scientifi c and practical interest.The development of regular multilayer construction technology with pre-programmed properties directly depends on progress in the development of controllable synthesis of high-purity surfactants. Meanwhile, practice shows that synthesis of high-purity surfactants, such as primary alkyl sulfates (one of the most commonly used and well-studied class of surfactants), encounters considerable diffi culties in removing impurities. Diffi culties in treating alkyl sulfates to remove primary alcohols have been reported elsewhere [3][4][5][6][7]. The same can be said about removal of tetradecyl alcohol from tetradecyl sulfate [3]; it retains even though the surface tension isotherm minimum, criterion of SAA purity, is lacking. Commercially pure sodium dodecyl sulfate always contains traces of dodecanol [7]. Traditional methods of the treatment (recrystallization, extraction, foam fractionation, and vacuum sublimation) do not often yield the desired result.It was shown that this arises from disregard of specifi city of SAAs as micellization systems and their ability to interact with the mixture components (primaryl alcohols in the case of alkyl sulfates).In the study, the effect exerted by micellization on the phase separation upon purifi cation of SAAs by crystallization from solutions was determined and a simple method was suggested for the synthesis of chemical purity colloids of alkyl sulfates, which satisfy to the requirements of modern high technology. EXPERIMENTAL Sodium dodecyl sulfate (AS-12) and sodium hexadecyl sulfate (AS-16) were synthesized from corresponding alcohols (chemical purity grade) by the method reported in [8]. The resulting products were purifi ed according to our method described in the fi nal part of the article. The electrical conductivity polytherms were obtained with a Р 5021conductometer at a heating rate not exceeding 0.5 deg min -1 at continuous agitation.
Durch Veresterungen des Anhydrids (I) mit entsprechenden Alkanolen in Gegenwart von TiOg ° n TiOSO4 in Tetrachlormethan bei 70°C (Reaktionsdauer 1 Std.) und Additionen von Na, SO3 an die entstehenden Diester (II) in wäßriger Lösung bei 60°C (0,5 Std.) lassen sich glatt die Titelverbindungen (III) (Ausbeute über beide Stufen 97‐98%) darstellen.
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