کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
202908 460627 2009 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Conductometric studies of aqueous ionic liquids, 1-alkyl-3-methylimidazolium halide, solutions at T = 298.15–328.15 K
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Conductometric studies of aqueous ionic liquids, 1-alkyl-3-methylimidazolium halide, solutions at T = 298.15–328.15 K
چکیده انگلیسی

Electrical conductances of aqueous ionic liquids, 1-butyl-3-methylimidazolium bromide, [BMIm]Br, 1-pentyl-3-methylimidazolium bromide, [PnMIm]Br, 1-hexyl-3-methylimidazolium bromide, [HMIm]Br, 1-butyl-3-methylimidazolium chloride, [BMIm]Cl, and 1-butyl-3-methylimidazolium iodide, [BMIm]I solutions at low concentrations of ionic liquids have been measured at (T = 298.15–328.15 K). The ion association constants, KA, limiting molar conductivities, Λ0 and distance parameters, R were obtained using low concentration Chemical Model (lcCM) conductivity equation for the investigated systems. The results show that the KA values decrease with lengthening alkyl chain and larger size of anion; i.e. Cl−< Br− < I−. Therefore, there is slight ion association effect in [BMIm]Cl at all experimental temperatures. Furthermore, the KA and Λ0 values for the aqueous solutions of ionic liquids increase as the temperature increases. Thermodynamic functions such as Gibbs free energy, enthalpy and entropy of ion pair formation were calculated using KA values. Results also show that ΔHA0 values exhibit weak dependence on the temperature this shows that ion pair formation of ionic liquids in water is the entropy driven process.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Fluid Phase Equilibria - Volume 286, Issue 2, 15 December 2009, Pages 120–126
نویسندگان
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