The Influence of Dissolved Electrolytes on the Miscibility of Binary Liquid Systems with Closed Miscibility Gaps

Abstract

Electrolytes J Liquids J Solutions J ThermodynamicsThe dependence of the upper and lower critical solution temperatures T, of the systems (1) oxolane + water, and (2) 2-butoxyethanol + water on the mole fraction xEl of dissolved 1-1,2-1, and 3-1 electrolytes has been investigated. The material stability of the homogeneous state of both systems is extremely sensitive to small electrolyte concentrations so that the observed shift of T, may be interpreted as the result of a perturbation of the mutual solvation of both non-electrolytes by ion solvation. Cations destabilize homogeneity in the order Me+ < Me2+ <Me3+. The nature of the anions, however, for which the order CI-> Br-> I-> NO, > C 1 0~ is established, determines whether the closed miscibility gap expands, shrinks, or is shifted to higher temperatures with increasing xEl. The importance of the anions is evident from a comparison of MgClz and Mg(CIO,),, for which the lower critical solution temperatures of oxolane + water at xEl = 0.003 differ by about 70 K.

Stability of Dilute Colloidal Silica Suspensions in the Vicinity of the Binodal Curve of the System 2-Butoxyethanol/Water

“…The experimen-C 4 E 1 /water, SiO 2 mixtures to lower values compared with tal basis for this finding is broadened by the results reported the system C 4 E 1 /water [T P (C 4 E 1 /water) 0 T P (C 4 E 1 /water, in this contribution: The stability of the dilute dispersion of SiO 2 ) É 1 K]. This is in agreement with the literature (14 homogeneous suspension. The C 4 E 1 minority phase b is free of colloidal particles.…”

Flow battery recharging by thermoresponsive liquid–liquid phase separation

“…The binary mixtures of water–LT and water–BE have an LCST at 34 °C (ref. 21) and 48 °C, 24,25 respectively. For the redox species, ferro-/ferricyanide ions (Fe(CN) 6 4−/3− ) were used.…”

“…Furthermore, the effect of inorganic salts on the cloud point depends on the ionic species. 24,25,30,31 In previous studies of diverse research elds, many solvent systems have been reported to show the LCST or UCST behaviors, which include not only molecule solvents 21,24,25,31 but also ionic liquids 22,23,30,[32][33][34][35][36][37][38][39] and polymers. 23,[40][41][42] The large number of candidates for the electrolyte components enable the exible tuning of the operation temperature, which will contribute to the utilization of low-grade heat sources in a wide temperature range.…”