Mechanism of the Salt Effect on Micellization of an Aminosulfonate Amphoteric Surfactant

Abstract

The critical micellar concentrations (cmc's) of sodium dodecyldiaminosulfonate amphoteric surfactant (C12AS) in aqueous solutions containing seven inorganic salts with chloride anions were measured by tensiometry using the Wilhelmy plate method at 25 °C. The mathematical relationship between the cmc of C12AS and the concentration of an inorganic salt in an aqueous solution was established. The effect of an inorganic salt on micellization of C12AS was also discussed. The results show that the dependence of the cmc of C12AS on an inorganic salt within the range of the effective concentration of the inorganic salt investigated in this experiment can be well described by the linear equation. The decrease of the cmc with an inorganic salt may be mainly attributed to the salting-out effect of the hydrophobic moiety of C12AS. Except for the salting-out effect, the causes can be partly from the vital contributions of both the electrostatic interaction between ionic heads of C12AS and the hydration of inorganic ions in the process of micellization. Also, the type of inorganic ion can affect the process of micellization. The data of Gibbs energy changes show that there is a spontaneous process of micellization, and the addition of an inorganic salt in an aqueous solution is favorable thermodynamically to the process of micellization.

Thermogelling, ABC Triblock Copolymer Platform for Resorbable Hydrogels with Tunable, Degradation‐Mediated Drug Release

“…[20] This early gelation effect was also particularly evident with the PDN formulation, possibly due to its slightly longer PNIPAAM block length compared to CDN and LGDN. [21] …”

Experimental Investigations of Behaviour of Biosurfactants in Brine Solutions Relevant to Hydrocarbon Reservoirs

“…The results of Greenzyme and rhamnolipid solubility in brine of varied composition and concentration are related to salting-in and salting-out effects [2,38,39]. The observed solubility of Greenzyme in all the investigated solutions indicate its tolerance to high salinity conditions which may be related to its high hydrophilicity.…”

Investigation of mixed micellization study of sodium dodecyl sulfate and tetradecyltrimethylammonium bromide mixtures at different compositions: Effect of electrolytes and temperatures

“…[29] The cmc values of SDS/SDS + TTAB mixture were observed to be declined in the presence of electrolytes (Tables 1 and 2) illustrating the impact on the micellization phenomenon. [33][34][35][36][37][38] The monomeric ionic surfactants form an ionic monolayer having own potential energy and thickness. [39] which declines with the insertion of salts and lowers the electrostatic repulsive force amongst the polar heads consequently cmc reduces.…”

“…[39] which declines with the insertion of salts and lowers the electrostatic repulsive force amongst the polar heads consequently cmc reduces. [34][35][36][37][38] The repulsion among the polar heads of the ionic surfactants is the postponing energy for micellization of ionic surfactants [40][41][42] which reduces in the presence of electrolytes. The extent of the interaction amongst the studied ingredients can be assessed from the deviation of experimental cmc values from the corresponding cmc id values.…”

“…The estimation of different thermodynamic parameters for micellization of different surfactants in various electrolyte mediums is also reported in the literature. [34][35][36][37][38] The values of ΔS o m were positive in all solvent exploited for both distinct and mixed systems ( Table 4). monomeric form.…”