Formation of Vesicles and Micelles in Aqueous Systems of Tetrameric Acids as Determined by Dynamic Light Scattering |
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| Authors: | Lingling Ge Sébastien Simon Brian Grimes Erland Nordgård Johan Sjöblom |
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| Institution: | 1. Department of Chemical and Materials Engineering , University of Alberta , Edmonton Alberta, Canada;2. Ugelstad Laboratory, Department of Chemical Engineering , Norwegian University of Sciences and Technology (NTNU) , Trondheim, Norway |
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| Abstract: | A comprehensive dynamic light scattering (DLS) study on the system BP10Na4/water is presented. BP 10Na4 is a tetrameric fatty acid in sodium form. In order to change molecular packing conditions both electrolyte (NaCl) and alcohol (1-butanol, 1-pentanol) are added to the surfactant system. Phase diagrams of the systems reveal not only an extensive micellization, but also the occurrence of a lamellar liquid crystalline D phase. The DLS study shows an existence of vesicles at very dilute BP10Na4 concentrations ( ?cmc) and also a co-existence of micelles and vesicles at higher BP10Na4 concentrations. Cryo-TEM pictures verify the existence of the vesicles. Based on the DLS and SLS experiments the weight-average molar mass of the micelles are estimated to be 13500 g/mol at 100 mM NaCl and 22700 g/mol at 600 mM. The corresponding aggregation numbers are 13 and 22, respectively. |
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| Keywords: | Light scattering micelles tetraacids vesicles |
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