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

Abstract

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 ρ, sound velocity u, absolute viscosity η, and their derived properties including the isentropic compressibility κS, excess molar volume VmE, excess sound velocity uE, excess isentropic compressibility κSE, absolute viscosity deviation Δη, excess logarithmic absolute viscosity lnηE, Gibbs energy of activation of viscous flow ΔG*, and the excess Gibbs energy of activation of viscous flow ΔG*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, κSE 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.