離子液體之熱物性質量測研究

Measurements of the thermodynamic properties of ionic liquids

于雅江風(Ya-Hung Yu)

指導教授 ： 李夢輝

中原大學/工學院/化學工程學系/碩士(2008年)

https://doi.org/10.6840/cycu200800299

摘要

摘要
本實驗量測九個離子液體與兩種雙成份離子水溶液之比熱與電導度，主要量測系統如下: [Bmim][BF4] (1-butyl-3-methylimidazolium tetrafluoroborate), [Bmim][PF6] (1-butyl-3-methylimidazolium hexafluorophosphate), [Bmim][CF3SO3] (1-butyl-3-methylimidazolium trifluoromethanesulfonate), [Bmim][MeSO4] (1-butyl-3-methylimidazolium methylsulfate), [Emim][BF4] (1-ethyl-3-methylimidazolium tetrafluoroborate), [Emim][CF3SO3] (1-ethyl-3-methylimidazolium trifluoromethanesulfonate), [Emim][C2N3] (1-ethyl-3-methylimidazolium dicyanamide), [Emim][ES] (1-ethyl-3-methylimidazolium ethylsulfate), and [Emim][MDEGSO4]) (1-ethyl-3-methylimidazolium 2-(2-methoxyethoxy) ethylsulfate); 及雙成份離子水溶液( [Bmim][BF4]/ H2O和[Bmim][PF6]/ H2O )。比熱主要利用示差掃描熱量計(Differential Scanning Calorimeter, DSC) 量測比熱，溫度範圍為303.2–393.2 K，其不確定性為0.015 (kJkg-1K-1); 並利用電導度計量測電導度，溫度範圍為293.2–353.2 K，其不確定性為0.001 (mScm-1)。本實驗研究值與文獻值有良好之符合性，實驗所量測之離子液體比熱值與電導度值以溫度為變數做迴歸計算，比熱值使用二次方經驗式，雙成份則是利用過剩比熱代入Redlich-Kister展開式予以迴歸計算; 電導度值則是利用修改後之VTF-type (Vogel-Tamman-Fulcher) 方程式得到迴歸值，雙成份則是使用其他學者所提出之模式來建立迴歸計算，迴歸計算值與實驗值亦有良好之符合性。本研究成果可作為工程設計基礎數據與計算依據。

關鍵字

比熱 ； 離子液體 ； 電導度

並列摘要

Abstract
The heat capacities and electrical conductivities of nine pure ionic liquid systems and two binary aqueous solutions of ionic liquids have been measured. The investigated ionic liquid systems were as follows: pure systems [Bmim][BF4] (1-butyl-3-methylimidazolium tetrafluoroborate), [Bmim][PF6] (1-butyl-3-methylimidazolium hexafluorophosphate), [Bmim][CF3SO3] (1-butyl-3-methylimidazolium trifluoromethanesulfonate), [Bmim][MeSO4] (1-butyl-3-methylimidazolium methylsulfate), [Emim][BF4] (1-ethyl-3-methylimidazolium tetrafluoroborate), [Emim][CF3SO3] (1-ethyl-3-methylimidazolium trifluoromethanesulfonate), [Emim][C2N3] (1-ethyl-3-methylimidazolium dicyanamide), [Emim][ES] (1-ethyl-3-methylimidazolium ethylsulfate), and [Emim][MDEGSO4]) (1-ethyl-3-methylimidazolium 2-(2-methoxyethoxy) ethylsulfate); binary aqueous systems (1-butyl-3-methylimidazolium tetrafluoroborate + water, and 1-butyl-3-methylimidazolium hexafluorophosphate + water). The heat capacities were measured over the temperature range from (303.2 to 358.2) K using a differential scanning calorimeter (DSC). The electrical conductivities were measured using a commercial conductivity meter in the temperature range from (293.2 to 353.2) K. The estimated uncertainties of heat capacity CP and electrical conductivity  measurements were 0.015 (kJkg-1K-1) and 0.001 (mScm-1), respectively. For systems in which literature data were available, a comparison was made and the results of this study were in good agreement with the available literature data. The heat capacity and electrical conductivities were presented as a function of temperature. For pure systems of ionic liquids, the temperature dependence of CP values were represented using a second order empirical equation and the temperature dependence of  values were correlated using a modified version of VTF-type (Vogel-Tamman-Fulcher) equation. For the studied binary aqueous solutions, the excess CP values were represented using a typical Redlich-Kister expansion and the  values were correlated using equations from other investigators. The correlations give satisfactory results. The heat capacities and electrical conductivities presented in this work are, in general, of sufficient accuracy for most engineering-design calculations.

並列關鍵字

electrical consuctivity ； ionic liquids ； heat capacity

參考文獻

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