Thermophysical study of binary mixtures of 1-butyl-3-methylimidazolium nitrate ionic liquid + alcohols at different temperatures

Abstract

New experimental data of density and viscosity for the binary mixtures of 1-butyl-3-methylimidazolium nitrate ([Bmim][NO3]) with + 2-propanol, 2-butanol and 2-pentanol are reported over the entire range of mole fraction at T = (293.15–323.15) K. To elucidate possible intermolecular interactions between the chemical species present in solutions, the excess molar volume, VmE thermal expansion coefficient, α excess thermal expansion coefficient, αE the isothermal coefficient of excess molar enthalpy, ∂HmE/∂PT,x partial molar volume, Vi¯ and deviation in viscosity, Δη were calculated. The excess molar volume of the binary mixture is negative over the entire mole fraction range and becomes more negative with increase in the temperature. Deviation in the viscosity is negative over the whole range of composition and decreases with increasing temperature. The obtained excess molar volume and deviation in viscosity were fitted to the Redlich–Kister polynomial equation. The experimental results have been discussed regarding molecular interactions and the formation of complex between unlike molecules. Influences of temperature and carbon chain length of alcohols were discussed.