The phase behavior of binary liquid mixtures of the ionic liquids (ILs) 1,3dimethylimidazolium bis((trifluoromethyl) sulfonyl) amide (C 1 mimNTf 2 ) and 1-methyl-3propyl imidazolium bis ((trifluoromethyl) sulfonyl) amide (C 3 mimNTf 2 ) with n-alkyl alcohols (C n OH; 3 ≤ n ≤ 8) was investigated. The phase diagrams are obtained by applying the cloud-point method on a set of synthetically prepared samples. Partial miscibility with an upper critical solution temperature (UCST) was observed. The study focuses on the determination of the liquid−liquid phase behavior in a temperature range of (267−423) K at atmospheric pressure. UCSTs were observed in between 280 K and 415 K. The results are complementing prior measurements on similar IL-C n OH systems concerning ILs with longer side chain. A numerical analysis of the phase diagrams on the basis of Ising criticality was applied presuming the validity of the rectilinear diameter or a nonlinear diameter as requested by the theory of complete scaling. The results (UCST, critical composition, width, and diameter) of the coexistence curves are compared with prior discussed results for higher C x mimNTf 2 systems.

Systematic investigations on the liquid–liquid phase behavior of binary mixtures of ionic liquids (IL) of the type 1-alkyl-3-methylimidazolium bis­((trifluoromethyl)­sulfonyl)­amide (C x mimNTf2, x = 2, 4, 6, 8, and 10) with n-heptanol and its branched isomers 3-ethyl-3-pentanol and 2,4-dimethyl-3-pentanol have been performed. The phase diagrams were determined at atmospheric pressure in the temperature range (T) of 263–448 K by applying the cloud point method. The phase diagrams are analyzed in terms of well-established numerical concepts based on Ising criticality. The results are discussed, and trends and explanations for the shifts of the range of solubility are given. The systems show partial miscibility with upper critical solution temperatures. Comparing the solutions in branched alcohols with those in the linear isomer, the critical solution points are found to be remarkably shifted toward higher temperatures and lower IL contents. The trend becomes more pronounced for ILs with shorter alkyl side chains where also a change of the shape of the phase diagrams is observed.