The effects of temperature, alkyl chain length, and anion type on thermophysical properties of the imidazolium based amino acid ionic liquids

Ionic liquids are promising materials for several applications. Amino acid based ionic liquids (AAILs) as a sort of a new generation of ionic liquids are recently proposed taking advantage of hydrogen bonding group and low toxicity. Three types of AAILs are examined in this work; namely 1-Octyl-3-Methylimidazolium Glycine [OMIM][Gly], 1-Octyl-3-Methylimidazolium Alanine [OMIM][Ala] and 1-Octyl-3-Methylimidazolium Proline [OMIM][Pro]. The pH and molar conductivity are measured at ambient conditions for AAILs aqueous solutions at different concentrations; specifically 1, 10, 20, and 30 wt.%. The experimental results show that all AAILs solutions are alkaline (pH>7) where [OMIM][Pro] has the highest pH compared to its counterparts. The trend is reversed for molar conductivity as [OMIM][Gly] showed the highest molar conductivity. These results are attributed to the smaller size of [Gly] compared to [Pro] and [Ala]. However, adding AAILs increases the molar conductivity of the water.

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“…where their values were also comparatively lower than published data for AAILs with short alkyl chain length [21]. Papancea et.…”

Section: Introductioncontrasting

confidence: 58%

pH and electrical conductivity measurements of aqueous solutions of amino acid-based ionic

et al. 2021

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“…At infinite temperature, interactions contributing to the viscosity at room temperature in RTILs are no longer effective and the value of ∞ is purely governed by geometric structure of the RTIL ions. Therefore, it may be representative of a structural contribution of the ions to the viscosity [28,33]. Indeed, at high temperature, interactions that contribute to viscosity such as Van der Waals interaction force between long alkyl chains, H-bonding of anions, and molar weight of the component ions) are no longer effective.…”

Section: Resultsmentioning

confidence: 99%

Effect of the chain lengthening on transport properties of imidazolium-based ionic liquids

Khalil

Chaabene

AZAR

et al. 2020

Fluid Phase Equilibria

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The objective of this work is to study the effect of the lengthening of the linear alkyl chain of the imidazolium cation on some transport properties. We focused on hydrophobic ionic liquids based on bis(trifluoromethanesulfonyl)imide anion. Among the different properties, we measured at the viscosity and ionic conductivity of four different 1-alkyl-3-methylimidazolium ionic liquid in the temperature range between 293 to 333K. Thus, Electrochemical windows of these ionic liquids and the diffusion coefficient of ferrocenemethanol (FcMeOH) in the four ionic liquids were studied using cyclic voltammetry at 298K. The FcMeOH diffusion coefficient was found to be higher in shorter alkyl chain ionic liquids.

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“…In this context, it is essential to study the effect of the alkyl chain length of the phosphonium cations on their physicochemical properties and its effect on the electrochemical performance when using them as electrolytes, specifically, due to the influence that it has on the transport properties [30,31] and even on electrochemical stability [16] …”

Section: Introductionmentioning

confidence: 99%

Four Phosphonium‐based Ionic Liquids. Synthesis, Characterization and Electrochemical Performance as Electrolytes for Silicon Anodes

et al. 2022

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Herein, we describe the synthesis, characterization and electrochemical performance of four phosphonium‐based ionic liquids (ILs) as electrolytes, Physicochemical properties such as viscosity, density, ionic conductivity, and thermal stability of ILs and conventional organic solvent ethylene carbonate (EC)/diethyl carbonate (DEC) were experimentally determined at different temperatures. All ILs showed thermal stability greater than 300 °C, surpassing the stability of the conventional organic solvent, whose flash points were 145 and 23 °C for EC and DEC, respectively. Nevertheless, at room temperature, all ILs are much more viscous than EC/DEC. The composite Si ‐[P2224][FSI] (triethyl‐n‐butylphosphonium bis(fluoromethylsulfonyl)imide) and Si‐EC/DEC anodes exhibit initial specific capacities at 0.15 A/g of 2409 and 2631 mAh/g, respectively. This demonstrates that despite the inferior transport properties of ILs, short alkyl‐substituted phosphonium ILs like [P2224][FSI] are potentially competitive for the new generation of electrolytes for LIBs. NMR, DSC, TGA, and galvanostatic discharged/charged were used as characterization techniques.

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The effects of temperature, alkyl chain length, and anion type on thermophysical properties of the imidazolium based amino acid ionic liquids

Cited by 37 publications

References 72 publications

pH and electrical conductivity measurements of aqueous solutions of amino acid-based ionic

pH and electrical conductivity measurements of aqueous solutions of amino acid-based ionic

Effect of the chain lengthening on transport properties of imidazolium-based ionic liquids

Four Phosphonium‐based Ionic Liquids. Synthesis, Characterization and Electrochemical Performance as Electrolytes for Silicon Anodes

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