Physicochemical properties of switchable-hydrophilicity solvent systems: N,N-Dimethylcyclohexylamine, water and carbon dioxide

For switchable hydrophilicity solvent (SHS) systems (N,N-Dimethylcyclohexylamine (DMCA), water, and carbon dioxide): the density, viscosity, refractive index and conductivity at (283.15-308.15) K and 0.1 Mpa, were measured. The apparent molar volumes were determined as a function of composition at each temperature from experimental data. Based on Masson's equation limiting apparent molar volumes and Masson's coefficient Sy describing the character of interactions were calculated. The relative viscosity values were adjusted to obtain the viscosity B coefficients and dB/dT values. It has been observed that there exist strong solute-solvent and solute-solute interactions in these systems, and DMCAH-bicarbonate salt acts as structure-maker in aqueous solvent. (C) 2019 Elsevier Ltd.