Aggregation structure in {water + tert-butanol + benzyl alcohol} ternary solution: Measurements of density and conductivity

Abstract In this work, the densities of {water + tert-butanol (TBA) + benzyl alcohol (BA)} ternary solutions were measured, from which the formation and structure transition in {water + TBA + BA} ternary solutions were investigated and discussed. In {water + TBA + BA} ternary solution, at fixed mole number of BA molecules, the BA molecules in the system first present as free BA molecules and BA/TBA dimers, while further increase of TBA concentration would result in the interactions of BA molecules with different types of TBA/water aggregates that was directly reflected by the change of the volumetric properties. Moreover, the change of molar conductivity Λm(NaBr) of NaBr and the maximum absorbance length of methyl orange λmax in ternary system have been determined at different fixed values of TBA concentrations, where various changes of Λm(NaBr) and λmax with BA mass fraction were displayed due to the formation and transition of different microstructures. The results reported herein suggested that the fine structure transitions in hydrotrope solutions can be well reflected by the variance of thermodynamic properties, which may provide an efficient way to investigate the structure change in aqueous hydrotrope solution.