Solubilities of AOT Analogues Surfactants in Supercritical CO₂ and HFC-134a Fluids

Abstract

A series of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) analogue surfactants [sodium dibutyl sulfosuccinate (DBSS), sodium dipentyl sulfosuccinate (DPSS), sodium dihexyl sulfosuccinate (DHSS), and sodium dioctyl sulfosuccinate (DOSS)] were synthesized and characterized with 1 H NMR and elemental analysis. The solubilities of surfactants in supercritical CO 2 (scCO 2 ) and supercritical 1,1,1,2-tetrafluoroethane (HFC-134a) fluids at a temperature range from (308 to 338) K and under pressures of (10 to 30) MPa were measured using a static method coupled with gravimetric analysis. The solubilities of these surfactants are much higher in HFC-134a fluid as compared with that in scCO 2 . The solubilities increased with increasing temperature and pressure for both scCO 2 and HFC-134a fluids. The solubilities in scCO 2 increased with increasing carbon atom number of surfactant, whereas they decreased with increasing carbon atom number of surfactant in HFC-134a. The density of scCO 2 was simulated with the Peng-Robinson (P-R) equation. The experimental data were used to validate the accuracy of the P-R equation.

Solubilities of l-Proline in Subcritical HFC-134a and Supercritical CO2 Fluids

“…However, HFC-134a is a polar solvent that has a strong solvent power for polar solutes. Since the dipole−dipole force between polar solute and HFC-134a promotes dissolution, the solubility of l -proline in HFC-134a is higher than in scCO 2 …”

“…The P-R equation can apply to many complex systems based on supercritical fluids. In previous work, 32 we have derived a P-R equation.…”

Amphiphile self-assemblies in supercritical CO2 and ionic liquids

“…His research interests include properties of green solvent systems and applications of green solvents in green chemistry. microemulsions, [28][29][30][31][32][33][34][35][36][37] and their applications in nanoparticle synthesis [38][39][40][41][42][43][44][45][46][47] and chemical reactions. [48][49][50][51][52] Since 2009, much effort has been devoted to the formation, properties and applications of scCO 2 -continuous microemulsions.…”

Phase equilibrium for surfactant Ls-54 in liquid CO2 with water and solubility estimation using the Peng–Robinson equation of state

“…Many papers on the design of CO 2 -compatible surfactants and formation of water-in-CO 2 microemulsions have since emerged. The most effective compounds reported to stabilize water-in-CO 2 microemulsions are the partially or fully fluorinated surfactants [16-18], especially the fluorinated sodium bis(2-ethylhexyl)sulfosuccinate (AOT) analogue [19, 20]. …”