An Isotropic Model for Micellar Systems:  Application to Sodium Dodecyl Sulfate Solutions

Abstract

A theoretical description of ionic micellar solutions, which are considered as a mixture of two fully dissociated electrolytes with a common ion, is proposed. The solution is modeled within the framework of an improved primitive model, in which the solution permittivity as well as the charge and size of the solutes are allowed to vary with surfactant concentration. The MSA theory is used to estimate the electrostatic interactions, and the Carnahan-Starling approximation is employed to evaluate the hard-sphere contributions to the osmotic and activity coefficients. The experimental osmotic coefficients of sodium dodecyl sulfate (SDS) solutions are reproduced by using a value of 1.9 + 4CT nm for the micellar radius, CT being the total surfactant molar concentration. This is the only adjustable parameter in the theory, and the agreement with published estimations of the size of SDS micelles is excellent.

MS2 and Qβ bacteriophages reveal the contribution of surface hydrophobicity on the mobility of non‐enveloped icosahedral viruses in SDS‐based capillary zone electrophoresis

“…Prior CZE analyses, the CMC of SDS in the BGE was estimated by dynamic light scattering and zeta potential measurements in the presence of SDS at 0.1, 1, 2, 4, 6, 8 or 10 mM (see Supporting Information). Colloids appeared from [SDS] = 4–6 mM, exhibiting a hydrodynamic diameter of 4 ± 1 nm and a negative zeta potential of about ‐61.5 ± 4.1 mV, corresponding well to SDS micelles . The CMC of SDS in the BGE used here was thus considered near 5 mM, in agreement with Kremser et al .…”

Antibacterial Efficacy of Gold and Silver Nanoparticles Functionalized with the Ubiquicidin (29–41) Antimicrobial Peptide

“…The mean hydrodynamic diameters, determined by DLS, showed no significant changes in stabilized SDSnanoparticles. Molero formation at concentrations below 8 mM has no significant increase on micellar diameter [33]. Measured diameters were 12.3 ± 3.9 nm and 14.4 ± 4.3 nm for AgNP and AgNP-UBI and 14.5 ± 5.7 and 16.5 ± 6.2 nm for AuNP and AuNP-UBI, respectively (Figure 2(a)).…”

A comparison study between sodium dodecyl sulfate and sodium dodecyl sulfonate with respect to the thermodynamic properties, micellization, and interaction with poly(ethylene glycol) in aqueous solutions

“…These properties are indispensable to test various theories and models of surfactant solutions [1][2][3]. However, in colloidal chemistry, these thermodynamic properties seem to be rarely determined experimentally, in contrast to electrolyte solution chemistry or biology [4].…”