Temperature Dependence on Density, Viscosity, and Electrical Conductivity of Ionic Liquid 1-Ethyl-3-Methylimidazolium Fluoride

Fengguo Liu,Junli Xu,Zhongning Shi,Ali Kamali,Xiongwei Zhong

doi:10.3390/app8030356

Abstract

Ionic liquids are considered environmentally friendly media for various industrial applications. Basic data on physicochemical properties are significant for a new material, in terms of developing its potential applications. In this work, 1-ethyl-3-methylimidazolium fluoride ([EMIm]F) ionic liquid was synthesized via an anion metathesis process. Physical properties including the density, viscosity, electrical conductivity, and thermal stability of the product were measured. The results show that the density of [EMIm]F decreases linearly with temperature increases, while dynamic viscosity decreases rapidly below 320 K and the temperature dependence of electrical conductivity is in accordance with the VFT (Vogel–Fulcher–Tammann) equation. The temperature dependence of the density, conductivity, and viscosity of [EMIm]F can be expressed via the following equations: ρ = 1.516 − 1.22 × 10−3 T, σm = 4417.1exp[−953.17/(T − 166.65)] and η = 2.07 × 10−7exp(−5.39 × 104/T), respectively. [EMIm]F exhibited no clear melting point. However, its glass transition point and decomposition temperature are −71.3 °C and 135 °C, respectively.

Highlights

Ionic liquids (ILs) are molten salts comprised entirely of cations and anions with a melting point below 100 ◦ C
Tokuda and co-workers [21,22,23] systematically studied the effect of ionic structures, including anionic species, cationic species, and alkyl chain, in imidazolium cation on the physicochemical characteristics characteristics of of ILs
We focused on its physical properties including density, viscosity, conductivity, and thermal stability

Summary

Introduction

Ionic liquids (ILs) are molten salts comprised entirely of cations and anions with a melting point below 100 ◦ C. Tokuda and co-workers [21,22,23] systematically studied the effect of ionic structures, including anionic species, cationic species, and alkyl chain, in imidazolium cation on the physicochemical characteristics characteristics of of ILs. Alkyl-substituted imidazolium cation-based advantages in terms of superior fluidity and conductivity. For the molecular structure of alkyl-substituted imidazolium-based ILs, as shown in is typically methyl and R2 can generally be butyl [24,25,26,27,28,29,30,31], ethyl [32,33,34,35], or octyl [36]. We prepared [EMIm]F ionic liquid via an anion metathesis process

Materials

Synthesis

Physical

Discussion

During cooling from

Conclusions