A group contribution method to estimate the densities of ionic liquids

“…ILs have been accepted as a new class of "green" solvents for practical applications because of their unique combination of low volatility, negligible vapor pressure, chemical stability, high conductivity, wide electrochemical window, ability to dissolve organic and inorganic solutes and gases, and tunable solvent properties. 1,2,6 The last mentioned is probably the most attractive feature because it permits the desired properties to be adjusted depending on the application simply by means of a slight structural modification of the cation or the anion.…”

Section: Introductionmentioning

confidence: 99%

Effect of Temperature, Anion, and Alkyl Chain Length on the Density and Refractive Index of 1-Alkyl-3-methylimidazolium-Based Ionic Liquids

et al. 2015

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The density and refractive index of 15 room temperature ionic liquids (ILs) grouped according to whether they had the same cation or anion have been measured at atmospheric pressure in a temperature range from 293.15 K to 343.15 K. Changes in the physical properties have been quantified as a function of temperature and alkyl chain length for each cation or anion family. It has been observed that ionic liquid density increases when the alkyl length of the cation decreases but not with the molecular weight of the anion. We have proposed a new method to assign the ionic volume of each component in an IL that explains the trend, followed by all experimental data in this work, and allows us to predict the molecular volume and density of many ILs prior to synthesis. It was also seen that the refractive index increases as alkyl chain length of the cation increases. The temperature-dependent correlation between density and refraction index for the ILs studied has been quantified.

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“…The study was based on an assumption proposed by Rebelo et al [55,56] that the molar volume of the ILs can be obtained from the efective molar volumes of the ions considering the ionic liquid as an "ideal" mixture. Qiao et al [30] introduced the interaction between several substitutes on the same center in the partition of groups. For that, the same group structure atached to diferent substitutes may have diferent group values.…”

Section: Estimation By Group Contribution Methods (Gcmsmentioning

confidence: 99%

Predicting Density and Refractive Index of Ionic Liquids

Montalbán¹,

Collado-González²,

Baños³

et al. 2017

Progress and Developments in Ionic Liquids

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The determination of the physicochemical properties of ionic liquids (ILs), such as density and refractive index, is essential for the design of processes that involve ILs. Density has been widely studied in ILs because of its importance whereas refractive index has received less atention even though its determination is rapid, highly accurate and needs a small amount of sample in most techniques. Due to the large number of possible cation and anion combinations, it is not practical to use trial and error methods to ind a suitable ionic liquid for a given function. It would be preferable to predict physical properties of ILs from their structure. We compile in this work diferent methods to predict density and refractive index of ILs from literature. Especially, we describe the method developed by the authors in a previous work for predicting density of ILs through their molecular volume. We also correlate our experimental measurements of density and refractive index of ILs in order to predict one of the parameters knowing the other one as a function of temperature. "s the measurement of refractive index is very fast and needs only a drop of the ionic liquid, this is also a very useful approach.

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A group contribution method to estimate the densities of ionic liquids

Cited by 65 publications

References 18 publications

Physical properties of 3-methyl-N-butylpyridinium tricyanomethanide and ternary LLE data with an aromatic and an aliphatic hydrocarbon at T=(303.2 and 328.2)K and p=0.1MPa

Physical properties of 3-methyl-N-butylpyridinium tricyanomethanide and ternary LLE data with an aromatic and an aliphatic hydrocarbon at T=(303.2 and 328.2)K and p=0.1MPa

Effect of Temperature, Anion, and Alkyl Chain Length on the Density and Refractive Index of 1-Alkyl-3-methylimidazolium-Based Ionic Liquids

Predicting Density and Refractive Index of Ionic Liquids

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