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Specific chemistry of added salt has a strong effect on the solubility of chemicals. In this work we measure the effect of several inorganic 1:1 salts on the aqueous solubility of n-hexane. For KCl, NaCl, and NaBr, our data agree with previous measurements. The effect of NaNO3 is measured for the first time. Based on our data, we report the Setchenov salting-out constants and discuss the specific effect of added salt on the solubility of n-hexane. We apply the ePC-SAFT equation of the state to correlate our data and report parameters of this equation. Calculated results reproduce the experimental data quite well.

For the development of novel liquid extraction systems, systematic experimental data and methods of predicting liquid−liquid equilibria are required. In this work, we report experimental data for a family of aqueous biphasic systems (ABSs) containing 1-butyl-3-methylimidazolium bromide/chloride, 1hexyl-3-methylimidazolium bromide/chloride, and 1-methyl-3octylimidazolium bromide/chloride in the presence of an inorganic salt (K 2 HPO 4 or K 3 PO 4 ) and assess the predictive capabilities of the ePC-SAFT equation of state in its classical form. The experimental binodal data for eight ABSs have been obtained in a broad concentration range. Although the ePC-SAFT gives a good description of the properties of binary systems, the deviations between experimental and predicted tie lines for the ternary ABSs are significant and the predictions are not quantitative. Improvement in the electrostatic term of the model is required for better performance. We systematically study the partitioning of L-tryptophan, taken as a model solute, and discuss the effect of the alkyl chain length of the imidazolium cation [C n mim] + and the specific effect of the anion of ionic liquids (ILs) (chloride versus bromide). We show that the alkyl chain length of [C n mim] + has almost no effect on the partition coefficients of L-tryptophan (K Trp ) in the ABSs with K 3 PO 4 , while lower K Trp values are found for ILs with the [C 4 mim] + cation for the ABSs with K 2 HPO 4 . A substantial specific effect of the anion of ILs is only observed when the salting-out effect of the inorganic salt is most pronounced, i.e., in the case of the ABSs with K 3 PO 4 . It should be specially mentioned that K Trp values are higher for the ABSs studied in this work in comparison with the available literature data for other IL−salt−water ABSs. This fact implies that the investigated ABSs have high potential for the extraction of biocomponents.

The specific chemistry of added salt has a strong effect on the aggregation of surfactants. Although the molecular mechanism of this effect is still debated in the literature and there is no generally accepted quantitative theory, substantial progress has recently been achieved in the molecular thermodynamic modeling of ion-specific effects for solutions of ionic surfactants. In this work, we extend our previous aggregation model of ionic surfactants to solutions of nonionic surfactants in the presence of salts. Within this model, the specificity of ions is reflected by the difference in ionic diameters, the dispersion interaction with the micelle, and an effective parameter δ± that takes into account the hydration/dehydration of an ion in the micellar corona and is specific to every ion–surfactant head pair. The effect of specific salt on the hydrophobic contribution to the aggregation free energy is described via the Setchenov salting-out constants. We apply the model for sugar-based surfactants: n-alkyl glucosides and N-acyl-N-methylglucosides. This choice is motivated by the importance of this family of surfactants in biotechnology. We report the set of model parameters, including the Setchenov constants, for the surfactants in this family in combination with a number of 1:1 salts and illustrate good performance of the model in the description of the specific effect of added salt on the critical micelle concentration (CMC) and the growth of micellar aggregates.