2,2-Difluoroethanol (DFE) is an important aliphatic fluorine-containing chemical intermediate. During its preparation, an azeotropic mixture of DFE and water is formed. To recover DFE from its aqueous solution, liquid−liquid extraction was applied in this work with isopropyl acetate (IPAc) and ethyl acetate (EtAc) as the extractants. The liquid−liquid equilibrium (LLE) experimental data for these ternary mixtures (EtAc/IPAc + DFE + water) was determined at 298.15 and 308.15 K under 101.3 kPa.To access the extraction performance of extractants EtAc and IPAc, the selectivity (S) and distribution coefficient (D) were calculated from the measured data. The results showed that the S and D values of IPAc were higher than those of EtAc, implying that IPAc is a suitable extractant. The Othmer−Tobias, Bachman, and Hand methods were applied to examine the reliability of the LLE experimental values. The UNIQUAC and NRTL models were adopted to fit the measured LLE data, and the calculated values of the root-mean-square deviation for the two models were less than 0.003.

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Several additives (NaSal, 1SHNC, and 2SHNC) were added into aqueous solutions of a cationic surfactant, 3-tetradecyloxy-2-hydroxy-propyl trimethyl ammonium bromide (R 14 HTAB). The mixed solutions were investigated using rheological measurements, molecular dynamics (MD) simulations, cryogenic transmission electron microscopy (cryo-TEM), 1 H NMR, and Fourier transform infrared (FTIR) spectroscopy. The results demonstrated that the zero-shear viscosity (η 0 ) increased with increasing salt concentrations until reaching a maximum and then decreased. The variations in viscosity were related to transformation of the micellar configuration and were confirmed by cryo-TEM and MD simulations. The ability of the three organic salts to enhance the viscoelasticity of R 14 HTAB solutions is in the order of NaSal < 1SHNC < 2SHNC. The synergistic interaction between counterions and surfactant molecules was analyzed using 1 H NMR spectrograms, FTIR spectroscopy, and MD simulations. These findings provide new insight into the self-assembly and bulk properties of ionic surfactant/organic salt mixtures.

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