Alkyl-chain length effect on physicochemical properties and molecular interactions for binary mixtures of N-ethylimidazole with n-alcohols at 298.15 K

In order to explore the alkyl chain effect of n-alcohols on physicochemical properties and molecular interactions of binary mixtures of N-ethylimidazole (abbreviated to N-Eim here after) with n-alcohols, based on our previous research of the binary mixture of N-Eim + methanol, for the new binary mixtures of N-Eim + ethanol, + 1-propanol, + 1-butanol, over a full molar fraction range and at 298.15 K and atmospheric pressure, the density rho, sound velocity u, absolute viscosity eta, and their derived properties including the isentropic compressibility kappa S, excess molar volume VmE , excess sound velocity uE, excess isentropic compressibility kappa SE, absolute viscosity deviation Delta eta, excess logarithmic absolute viscosity ln eta E, Gibbs energy of activation of viscous flow Delta G*, and the excess Gibbs energy of activation of viscous flow Delta G*E were measured, calculated and analyzed. It was found that, with n of n-alcohols increasing, the molecular interaction between unlike molecules is, for the mixtures of N-Eim + methanol, + ethanol, stronger than that between like ones, and for the mixture of N-Eim + 1-propanol, similar to that between like ones, while for the mixture of N-Eim + 1-butanol, weaker than that between like ones. A stronger molecular interaction between unlike molecules domains the magnitudes of VmE , kappa SE and uE for the mixtures of N-Eim + methanol, + ethanol, while more effective molecular accumulations in the mixtures domain them for the mixtures of N-Eim + 1-propanol, + 1-butanol. Absolute viscosity and its derived properties are more sensitive to molecular interactions than density, sound velocity and their derived properties for the four mixtures.