Effects of electrolytes on the surface and micellar characteristics of Sodium dodecyl sulphate surfactant solution

Abstract

The effect of some electrolytes (namely sodium acetate and calcium acetate) on their critical micelle concentration (CMC), have been determined by spectrophotometric, conductometeric and surface tension measurement method at 298K, 308K and 318K. From the surface tension data physico-chemical properties such as surface excess concentration (Γmax) and minimum area per molecule (Amin) at surface have been obtained. From the observed CMC data, free energy of micellization (∆Gmic), entropy change of micellization (∆Smic), and enthalpy change of micellizaton (∆Hmic) for the studied surfactant solutions with or without electrolyte have been obtained. The results have been interpreted in light of inter-molecular interaction.

Effect of Electrolytes on Solution and Interfacial Behaviors of Double Chain Cationic–Nonionic Surfactant Mixtures for Hydrophobic Surface Wetting and Oil/Water Emulsion Stability Applications

“…Addition of salt in surfactant systems is another important approach of reducing the CMC/CVC of binary mixtures where electrolytes normally reduce the electrostatic repulsion among the ionic head groups and thereby reduce the CMC/CVC of the ionic surfactants. 50 Therefore, observing the effect of electrolytes in mixed surfactant systems was carried out so as to In the absence of electrolyte, the lowering of CMC and surface tension for the mixed cationic−nonionic surfactant systems are because of the reduction of electrostatic headgroup repulsion between the cationic surfactant molecules after organizing the nonionic surfactant molecules in between. However, in the presence of electrolyte, further lowering of these parameters can be explained as (i) a compressed electrical double layer (reduction of Debye length, κ −1 ) and (ii) a higher charge shielding effect of multivalent counterions.…”

“…Addition of salt in surfactant systems is another important approach of reducing the CMC/CVC of binary mixtures where electrolytes normally reduce the electrostatic repulsion among the ionic head groups and thereby reduce the CMC/CVC of the ionic surfactants . Therefore, observing the effect of electrolytes in mixed surfactant systems was carried out so as to analyze the influence of mono-, di-, trivalent counterions (shown in Figure a, b) with different concentrations of binary mixtures of igepal and DDAB.…”

Importance of the Nanofluid Preparation for Ultra-Low Interfacial Tension in Enhanced Oil Recovery Based on Surfactant–Nanoparticle–Brine System Interaction

“…In method II, the surfactant mixture is added to the brine solution before the nanoparticles. The presence of electrolytes generates a higher concentration around the surfactant molecules, which promote the reduction of electrostatic forces between the charged hydrophilic components of surfactants, favoring the formation of micelles . Thus, the surfactant is probably adsorbed onto nanoparticles as micelles .…”

“…The presence of electrolytes generates a higher concentration around the surfactant molecules, which promote the reduction of electrostatic forces between the charged hydrophilic components of surfactants, favoring the formation of micelles. 55 Thus, the surfactant is probably adsorbed onto nanoparticles as micelles. 27 This situation is evidenced in the adsorbed amount of the surfactant onto nanoparticles, which is the highest among the evaluated methods.…”

Thermodynamics and Micellar Behavior of Surface-Active Drugs in Aqueous Solution of Electrolytes: Surface Tension Study

“…However, the presence of the electrolyte decreases the max  values and follows the order pure water > NaCl > KCl > RbCl and pure water > MgCl2 > CaCl2 > SrCl2. This is due to the stronger affinity between drug-electrolyte molecules, correlating the increase in the drug hydrophobicity by the electrolyte [13,39]. This suggests that the amphiphilic drug molecules get solubilized into bulk resulting into the lower max  values.…”