ISSN:
1435-1536
Keywords:
Electrophoretic light scattering
;
potentiometric titration
;
surface charge density
;
fractional binding
;
dodecyldimethylamine oxide
;
sodium dodecyl sulfate
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Electrophoretic light-scattering measurements and potentiometric titrations were carried out on aqueous mixtures of dodecyldimethylamine oxide and sodium dodecyl sulfate. The electrophoretic mobility and the surface charge density of the micelles were always negative, ranging from −2.5 to −3.1×10−4 cm2V−1s−1, and −0.033 to −0.045 cm−2, respectively, for all surfactant mixing ratios, indicating the specific adsorption of Cl−, in addition to Na+, on micelles. The solution pH, as well as the aggregation number previously reported, displayed maxima at intermediate surfactant mole fractions, that is, the non-ideal behavior. The fractional adsorption of Na+ per surfactant molecule in the micelles increased gradually with mixing fraction up to 0.82 atX=[SDS]/([SDS]+[C12DAO])=1, while that of Cl− decreased from 0.25 atX=0 to zero atX〉0.4.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00655688
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