Determination of critical micelle concentration in the thionin—sodium dodecyl sulphate micellar system

The values of the apparent dissociation constants of the azo dye 4-(2-pyridylazo)-resorcinol (PAR) have been found in the presence of sub- and supercritical concentrations of the anionogenic tenside sodium dodecyl sulphate (SDS) and the effects of the strong electrolytes NaCl and NaNO3 were also evaluated. In both electrolytes, the pKan values initially are independent of the SDS concentration and then increase. Spectrophotometric and surface tension measurements were employed to determine the critical micelle concentration (cmc) of SDS alone and in the presence of PAR and the given electrolytes. The determined cmc values were in the range 0.20–3.02 mmol l-1 and dependent on the type and concentration of the particular additive.

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An improved method for the spectrophotometric determination of fluoride by addition of sodium dodecyl sulphate to the fluoride/lanthanum (III)/Alizarin fluorine blue system

Analytica Chimica Acta ◽

10.1016/s0003-2670(00)86285-6 ◽

1985 ◽

Vol 178 ◽

pp. 331-335 ◽

Cited By ~ 13

Author(s):

M.E. Léon-González ◽

M.J. Santos-Delgado ◽

L.M. Polo-diez

Keyword(s):

Spectrophotometric Determination ◽

Sodium Dodecyl Sulphate ◽

Sodium Dodecyl ◽

Improved Method

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Diffusion Interactions of Some Biologically Important Transition Metal Complexes on Micellar Properties of Sodium Dodecyl Sulphate

Journal of Scientific Research ◽

10.3329/jsr.v4i1.7989 ◽

2011 ◽

Vol 4 (1) ◽

pp. 135

Author(s):

M. A. Hossain ◽

M. A. Rahman ◽

M. A. Subhan

Keyword(s):

Critical Micelle Concentration ◽

Metal Complexes ◽

Hydrophobic Interaction ◽

Sodium Dodecyl Sulphate ◽

Sodium Dodecyl ◽

Specific Conductance ◽

Micellar Aggregates ◽

Counter Ions ◽

Rate Of Increase ◽

Anionic Micelle

The specific conductance of aqueous solutions of sodium dodecyl sulphate (SDS) was measured from 20 to 35 ºC with an interval of 5 °C in the absence and presence of metal complexes such as [Cr(acac)2(H2O)2]Cl, K3[Fe(C2O4)3] and (NH4)4[Co(C6H5O7)2] at concentrations ranging from 2.0 × 10-4 to 8.0 x 10-4 M. The specific conductance rapidly increased at the pre-micellar region with increasing of temperature and concentration of SDS, but after critical micelle concentration (CMC) the rate of increase was slower. As the concentrations of metal complexes [Cr(acac)2(H2O)2]Cl, K3[Fe(C2O4)3] and (NH4)4[Co(C6H5O7)2] increased, the CMC of SDS decreased exponentially, which was sharp with increasing temperature. The CMC decreases due to the formation of pre-micellar aggregates of the positive counter ions of the complexes with dodecyl sulphate ions (DS-) and hydrophobic interaction between ligands of complexes and hydrophobic tail of SDS. The pre-micellar aggregate formation was essentially influenced by the counter ions binding abilities to the anionic micelle. The effect of metal complexes on lowering the CMC of SDS was found to follow the order [Cr(acac)2(H2O)2]Cl < K3[Fe(C2O4)3] < (NH4)4[Co(C6H5O7)2]. Thermodynamics of metal complexes with SDS and parameters of micellization ΔG°mic, ΔH°mic and TΔS°mic were calculated.Keywords: Surfactants; Sodium dodecyl sulphate; Critical micelle concentration; Pre-micellar aggregate; Hydrophobic interaction.© 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.7989J. Sci. Res. 4 (1), 135-141 (2012)

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