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Title: Structure-related mechanical properties of hydrogels of micelle-forming surfactantsстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 12 октября 2013 г.
- Авторы: Markina Z.N., Chirova G.A., Zadymova N.M.
- Журнал: Colloid Journal
- Том: 60
- Номер: 5
- Год издания: 1998
- Издательство: Pleiades Publishing, Ltd
- Местоположение издательства: Road Town, United Kingdom
- Первая страница: 568
- Последняя страница: 572
- Аннотация: The mechanism of structuring in aqueous solutions of typical micelle-forming surfactants (stabilizers for lyophilic disperse systems), soaps of higher organic acids, different in hydrophilic properties, and forming specific lyophilic disperse systems in water was studied at increased supersaturations. It was shown that, on crystallization from supersaturated micellar solutions, soaps of saturated acids form disperse systems, which completely immobilize the dispersion medium and have some properties characteristic of solids. The temperature dependences of the solubility of sodium laurate and myristate in water were studied by measuring equilibrium temperatures of crystallization from respective micellar solutions and subsequent dissolution of hydrated solid phase on cooling and heating with a very low rate (0.5 degrees C/h); for sodium laurate, the Krafft point was also determined. The mechanical properties of hydrogels of saturated soaps were measured. Based on the dependences of the ultimate shear stress (the strength) P-m on the surfactant concentration (C) and on the temperature obtained for sodium myristate and palmitate aqueous systems in the concentration range (0.5-20)x 10(-2) kg/kg and the temperature range 5-60 degrees C, three-dimensional strength diagrams were constructed. The process of formation and development of the three-dimensional structure in this systems was quantitatively considered by comparison of the sections of equal strength and solubility and gelation curves. It is found that, below the Krafft point, the strength of the systems did not depend on the temperature, which provided reliable determination of P-m of similar systems in the absence of the temperature effect. It was shown that, at C > 5 x 10(-2) kg/kg, the strength of the hydrogels with an identical soap content decreased sharply with increase in the chain length of soap molecules from C12 to C18. The mechanism of structuring in aqueous solutions of typical micelle-forming surfactants (stabilizers for lyophilic disperse systems), soaps of higher organic acids, different in hydrophilic properties, and forming specific lyophilic disperse systems in water was studied at increased supersaturations. It was shown that, on crystallization from supersaturated micellar solutions, soaps of saturated acids form disperse systems, which completely immobilize the dispersion medium and have some properties characteristic of solids. The temperature dependences of the solubility of sodium laurate and myristate in water were studied by measuring equilibrium temperatures of crystallization from respective micellar solutions and subsequent dissolution of hydrated solid phase on cooling and heating with a very low rate (0.5 degrees C/h); for sodium laurate, the Krafft point was also determined. The mechanical properties of hydrogels of saturated soaps were measured. Based on the dependences of the ultimate shear stress (the strength) P-m on the surfactant concentration (C) and on the temperature obtained for sodium myristate and palmitate aqueous systems in the concentration range (0.5-20)x10(-2) kg/kg and the temperature range 5-60 degrees C, three-dimensional strength diagrams were constructed. The process of formation and development of the three-dimensional structure in this systems was quantitatively considered by comparison of the sections of equal strength and solubility and gelation curves. It is found that, below the Krafft point, the strength of the systems did not depend on the temperature, which provided reliable determination of P-m of similar systems in the absence of the temperature effect. It was shown that, at C > 5x10(-2) kg/kg, the strength of the hydrogels with an identical soap content decreased sharply with increase in the chain length of soap molecules from C12 to C18.
- Добавил в систему: Задымова Наталья Михайловна