Related Experiment Video
Updated: Jun 9, 2026
16:24
Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
Published on: August 2, 2012
Molecular-level interactions governed by temperature and composition in double salt ionic liquid-water systems
K M Golam Rahman1, Mohammad Hossain1,2, Md Abu Bin Hasan Susan1,3
1Department of Chemistry, University of Dhaka Dhaka 1000 Bangladesh.
RSC Advances
|June 8, 2026
Summary
This study reveals how mixing ionic liquids creates a double salt ionic liquid (DSIL) with unique properties. The DSIL exhibits a more flexible structure and altered interactions with water, impacting its potential for green chemistry and energy storage applications.
Area of Science:
- Physical Chemistry
- Materials Science
- Chemical Engineering
Background:
- Ionic liquids (ILs) are tunable solvents with diverse applications.
- Understanding the thermophysical properties of IL mixtures is crucial for their effective use.
- Double salt ionic liquids (DSILS) offer unique properties derived from their constituent ILs.
Purpose of the Study:
- To investigate the thermophysical and dynamic properties of a novel double salt ionic liquid (DSIL) formed from [C4mim]BF4 and [C4mim][MeSO4].
- To explore the interactions between the DSIL and water across various temperatures and compositions.
- To elucidate the structural changes and molecular dynamics upon DSIL formation and its mixtures with water.
Main Methods:
- Volumetric and viscometric analyses were performed on ILs, DSIL, and DSIL-water binary systems.
- The Vogel-Fulcher-Tammann (VFT) model was used to analyze dynamic viscosity.
- Dynamic light scattering (DLS) was employed to study cluster formation.
Main Results:
- The formation of DSIL ([C4mim](BF4)0.5[MeSO4]0.5) from parent ILs ([C4mim]BF4 and [C4mim][MeSO4]) resulted in a transition from a rigid to a flexible ionic network.
- Positive excess molar volumes and reduced energy barriers for viscous flow were observed, indicating enhanced dynamic disorder.
- DSIL-water mixtures exhibited non-ideal behavior, with structural changes influenced by mole fraction, and DLS revealed distinct cluster sizes.
Conclusions:
- The coexistence of BF4- and [MeSO4]- anions in DSIL disrupts uniform packing, enhancing free volume and dynamic disorder.
- Water addition to DSIL reduces temperature sensitivity of viscosity and alters cluster dynamics.
- The findings provide critical insights into DSIL-water interactions, guiding applications in green chemistry, energy storage, and drug delivery.
Related Concept Videos
01:28Ionic Association
The ionic association is the association of oppositely charged ions in an electrolyte solution to form ion pairs. Bjerrum defined ion pairs as two oppositely charged ions whose electrostatic attraction exceeds the thermal energy of the system, typically expressed as 2kT. Electrostatic attraction depends on ionic charge, separation distance, and the dielectric constant of the medium. Thermal energy, represented by kT, reflects the tendency of ions to move independently due to molecular motion.
02:42Aqueous Solutions and Heats of Hydration
Water and other polar molecules are attracted to ions. The electrostatic attraction between an ion and a molecule with a dipole is called an ion-dipole attraction. These attractions play an important role in the dissolution of ionic compounds in water.
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
02:28Intermolecular Forces in Solutions
The formation of a solution is an example of a spontaneous process, a process that occurs under specified conditions without energy from some external source.
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
When the strengths of the intermolecular forces of attraction between solute and solvent species in a solution are no different than those present in the separated components, the solution is formed with no accompanying energy change. Such a solution is called an ideal solution. A mixture of ideal gases (or gases such as helium and argon,...
03:13Intermolecular Forces
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen bonds, and dispersion...
01:24Solid–Solid Solutions
The temperature-composition phase diagram of two solids, A and B, which are immiscible in the solid phase but form miscible liquids, shows that when the temperature is low, these two exist as separate, pure solids (A and B). As the temperature increases, they transition into a single-phase liquid solution where A and B coexist. Moving from point a1 to a2 in the phase diagram, the composition changes such that solid B begins to separate from the solution, enriching the remaining liquid with A.
02:54Molecular and Ionic Solids
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...