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Indexed by:期刊论文

Date of Publication:2010-04-01

Journal:JOURNAL OF SURFACTANTS AND DETERGENTS

Included Journals:SCIE、EI

Volume:13

Issue:2

Page Number:173-178

ISSN No.:1097-3958

Key Words:Tetradecylbenzene sulfonate; Isomers; Self-aggregation; Micelle; Vesicle

Abstract:This paper deals with the effect of the surfactant isomeric structure on self-aggregation in aqueous solution. The relationship between the molecular structure of a series of tetradecylbenzene sulfonate isomers (with the benzene ring located at different positions along the alkyl chain) and surface tension was made clear. It is found that the critical micelle concentration increases and the surface tension at critical micellar concentration decreases as the benzene group moves toward the center of the alkyl chain. The structure of micelles was studied by (1)H-NMR relaxation, which indicates that the density of methylene protons in the surface layer of the micellar core decreases as the branching of the hydrophobic group increases. The spontaneous vesicle formation in aqueous solution was investigated by transmission electron microscopy. The results reveal that, as the benzene group moves toward the center of alkyl chain, the assembly structure changes from micelle to vesicle, then to lamellar bilayers, while the critical packing parameter increases.