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The Effect of Ethanol on Nanostructures of Mixed Cationic and Anionic Surfactants
Author(s) -
Aslanzadeh Saeed,
Yousefi Ali
Publication year - 2014
Publication title -
journal of surfactants and detergents
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.349
H-Index - 48
eISSN - 1558-9293
pISSN - 1097-3958
DOI - 10.1007/s11743-013-1548-z
Subject(s) - chemistry , pulmonary surfactant , gibbs free energy , micelle , conductometry , ammonium bromide , gibbs isotherm , surface tension , sodium dodecyl sulfate , cationic polymerization , inorganic chemistry , counterion , dynamic light scattering , analytical chemistry (journal) , aqueous solution , chemical engineering , thermodynamics , chromatography , organic chemistry , nanoparticle , ion , biochemistry , physics , engineering
Micellization of tetradecyl trimethyl ammonium bromide (TTAB) and sodium dodecyl sulfate (SDS) in water–ethanol (ET) micellar solutions, with the weight percent of ET changing within the range 0–30, was studied by means of surface tension and conductivity measurements. Surface tension measurements also provided information about the dependence of the surface excess concentration, the minimum area per surfactant molecule, and the standard Gibbs energy of adsorption on the added weight percent of the organic solvent. Information about the degree of counterion dissociation and phase transition was obtained through conductivity measurements. Cyclic voltammetry (CV) and dynamic light scattering (DLS) was also employed to investigate the mixed micellar behavior of the binary mixtures. It was shown that an excess of cationic surfactant and ET resulted in a phase transition of vesicles and large micelles to mixed micelles. The regular solution theory approximation was used to determine various micellar parameters of ideal systems. The regular solution interaction parameter ( β ) suggests that the formation of mixed micelles is due to the synergistic interactions in the case of TTAB/SDS systems and becomes affected by the water/ET ratio.