Volumetric and Acoustic Properties of Binary Mixtures of the Ionic Liquid 1-Butyl-3-methylimidazolium Tetrafluoroborate [bmim][BF4] with Alkoxyalkanols at Different Temperatures

Densities, rho, and speeds of sound, u, of the solutions of the room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate [bmim][BF4] in ethylene glycol monomethyl ether (EGMME), diethylene glycol monomethyl ether (di-EGMME), and triethylene glycol monomethyl ether (tri-EGMME) have been measured over the whole composition range at T = (288.15 to 318.15) K. The density values have been used to calculate excess molar volumes, V-E, whereas speeds of sound results were used to calculate excess isentropic compressibilities, K-S,m(E). Excess properties are fitted to the Redlich-Kister polynomial equation to obtain the binary coefficients and the standard errors. The data obtained were analyzed to determine the effect of (i) temperature and (ii) the alkyl chain length of the alkoxyalkanols. Also, these results have been interpreted in terms of molecular interactions occurring in the binary mixtures of the present study.