Article ID Journal Published Year Pages File Type
611844 Journal of Colloid and Interface Science 2008 10 Pages PDF
Abstract

Mixed micelle formation and interfacial properties of aqueous binary and ternary combinations of hexadecyltrimethylammonium bromide (C16Br), hexadecylbenzyldimethylammonium chloride (C16BzCl) and polyoxyethylene (20) cetyl ether (Brij58) at 25 °C in 30 mM aqueous NaCl have been studied in detail employing tensiometric and fluorimetric techniques. The micellar and adsorption characteristics like composition, activity coefficients, mutual interaction parameters and free energy of micellization have been estimated using the theoretical approaches of Clint, Rosen, Rubingh, Blankschtein et al., Rubingh–Holland and Maeda. A comprehensive account of the comparative performance of these models on the selected cationic–cationic–nonionic surfactant mixtures at constant ionic strength has been presented. The Blankschtein model predicted lower synergism than from Rubingh's method because it neglects the contribution due to steric interaction between surfactant head groups of different sizes and charges. Free energy of micellization calculated using Maeda's approach, which employs interaction parameter and micellar mole fraction from Rubingh's model as inputs, shows good correlation with that calculated from commonly used phase separation model. The present study also reveals that the modified Rubingh–Holland method along with the Rosen's model can be applied to analyze the interfacial characteristics of ternary surfactant mixtures with a fair degree of success thereby widening the domain of applicability of this model.

Graphical abstractComparison of experimental critical micelle concentration of C16Br, C16BzCl and Brij58 in their various ternary combinations using Clint's, Blankschtein's, and Rubingh–Holland formulations.Figure optionsDownload full-size imageDownload as PowerPoint slide

Related Topics
Physical Sciences and Engineering Chemical Engineering Colloid and Surface Chemistry
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