Study of apparent molar volumes of ether functionalized ionic liquids with three ether solvents

The density of two functionalized ionic liquids (FILs) 1-methoxyethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([MOEmim][NTf 2 ] and 1-methoxyethyl-2,3-dimethylimidazolium bis[(trifluoromethyl)sulfonyl]imide [MOEmmim][NTf 2 ]) have been measured with ether solvents proprylene glycol monomethyl ether (PEGMME), diethylene glycol dimethyl ether (DEGDME), tetraethylene glycol dimethyl ether (TEGDME) at diluted concentration range. The determined temperature range is from 293.15 to 328.15 K at atmospheric pressure. The measured densities are used for the calculation of apparent molar volumes, V ϕ /m 3 ·mol −1 , at the temperature range. The effects of the ether ( O ) and methyl ( CH 3 ) introduction on imidazolium cation are discussed for the density and apparent molar volume in deeply. The Redlich-Rosenfeld-Meyer (RRM) equation was used for the fitting of apparent molar volumes, V ϕ /m 3 ·mol −1 , for the six studied dilute solutions. The infinite dilution apparent molar volumes, V ϕ /m 3 ·mol −1 , and limiting apparent molar expansibility, E Φ 0 / c m 3 · m o l - 1 · K - 1 ${E_{\mathrm{\Phi }}^0/{\mathrm{c}\mathrm{m}}^3·{\mathrm{m}\mathrm{o}\mathrm{l}}^{-1}·\mathrm{K}}^{-1}$ , have been obtained and discussed from the RRM equation and polynomial equation. The thermal expansion coefficients, α/K −1 , have also been calculated and discussed from density for the studied dilute solutions in the temperature range.