Two-Phase Region in the DTAB/SL Mixed Surfactant System

Abstract

The phase behavior as well as the microstructures of the dodecyltrimethylammonium bromide (DTAB)/sodium laurate (SL) aqueous two-phase system has been studied. By using FF-TEM, dynamic light scattering (DLS), a viscosity meter, and polarization microscopy, the effects of surfactant concentration and mixing ratio, temperature, salt concentration, and additives (octanol and toluene) on the phase separation have been systematically investigated. The phase separation is found to be strongly dependent on the variation of the surfactant aggregates. The different kinds of aqueous surfactant two-phase system can transit between each other upon the variation of the mixing ratio, the change of the salt concentration, and the addition of toluene and octanol.

Extraction of trace acetylspiramycin in real aqueous environments using aqueous two-phase system of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate and phosphate

“…The salting-out ability may also be related to the Gibbs energy of hydration of the ions. Considering the fact that these salts share a common cation but contain different anions, it is easy to see that the salting-out ability of the anions follows the order: CO 3 2-(ΔG hyd = -1315 kJ mol -1 ) > HPO 4 2-(ΔG hyd = -1125 kJ mol -1 ) [25,26]. This order is consistent with the Hofmeister series for the strength of the kosmotropic salts.…”

“…As can be seen, the studied salts' ability to promote phase separation follows the order: Na 2 CO 3 > Na 2 SO 4 > NaH 2 PO 4 . The kosmotropic ions, CO 3 2-, SO 4 2-and H 2 PO 4 -exhibit stronger interactions with water molecules, which are beneficial to the ILATPS formation. The salting-out ability may also be related to the Gibbs energy of hydration of the ions.…”

“…The partitioning of acetylspiramycin was carried out in an aqueous two-phase system (ATPS) formed by a hydrophilic ionic liquid (1-butyl-3-methylimidazolium tetrafluoraborate, [Bmim]BF 4 ) and NaH 2 PO 4 . This ATPS is a simple, non-toxic and effective sample pretreatment technique, which was developed for the simultaneous separation, enrichment and rapid analysis of acetylspiramycin coupled with molecular fluorescence spectrophotometry.…”

“…This ATPS is a simple, non-toxic and effective sample pretreatment technique, which was developed for the simultaneous separation, enrichment and rapid analysis of acetylspiramycin coupled with molecular fluorescence spectrophotometry. Analysis of the liquid-liquid equilibrium of [Bmim]BF 4 -salt ATPS demonstrated that the salting-out ability of different salts may be related to the Gibbs energy of hydration of the ions. The effects of types of salts, concentration of NaH 2 PO 4 , and temperature were analysed.…”

Rheology of Wormlike Micelles: Equilibrium Properties and Shear Banding Transitions

“…The growth of the micelles is assumed to arise from the charge neutralization of the surface potential (as in C) and from the related increase of the ionic strength (as in A). Recent examples studied are the mixtures of sodium dodecylsulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) [81,82], or the mixtures made from cetyltrimethylammonium tosilate and sodium dodecyl benzenesulfonate [83,84].…”