Molecular-Scale Solvation Structures of Ionic Liquids on a Heterogeneously Charged Surface
Kenichi Umeda1,2,3, Kei Kobayashi1, Taketoshi Minato4,5
1Department of Electronic Science and Engineering, Kyoto University, Katsura, Nishikyo, Kyoto 615-8510, Japan.
The Journal of Physical Chemistry Letters
|September 7, 2020
Summary
This study reveals sub-nanoscale solvation structures on charged surfaces using advanced atomic force microscopy. It shows how ions and water interact differently on positive and negative surface areas, crucial for ionic liquid device development.
Area of Science:
- Materials Science
- Surface Chemistry
- Physical Chemistry
Background:
- Understanding ionic liquid solvation is key for functional device applications.
- Previous work established atomic-scale solvation measurements using AFM and MD simulations.
- Verifying molecular distribution on heterosurfaces is essential for practical use.
Purpose of the Study:
- To unveil local solvation structures on a heterogeneously charged phyllosilicate surface.
- To investigate molecular distribution in ionic liquid and pure liquid solutions.
- To identify preferential adsorption and orientation of ions on charged surfaces.
Main Methods:
- Utilized ultralow noise 3D frequency-modulation atomic force microscopy (3D-FM-AFM).
- Integrated molecular dynamics (MD) simulations for comprehensive analysis.
- Identified adsorbed ion species based on molecular size and orientation.
Main Results:
- Demonstrated preferential adsorption of anions and cations onto oppositely charged surfaces.
- Showcased distinct orientations and water miscibility for adsorbed ions.
- Revealed the formation of neutral intermediate regions at boundary areas in ionic liquid and KCl solutions.
Conclusions:
- The study provides critical insights into sub-nanoscale solvation on heterogeneous surfaces.
- Experimental verification of molecular distribution is achieved.
- This technique is vital for advancing ionic liquid-based functional devices.
Related Concept Videos
03:13Intermolecular Forces
67.6K
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...
67.6K
02:55Solubility of Ionic Compounds
67.5K
Solubility is the measure of the maximum amount of solute that can be dissolved in a given quantity of solvent at a given temperature and pressure. Solubility is usually measured in molarity (M) or moles per liter (mol/L). A compound is termed soluble if it dissolves in water.
67.5K
03:00Solubility
20.4K
Solution, Solubility, and Solubility Equilibrium
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules,...
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules,...
20.4K
02:42Aqueous Solutions and Heats of Hydration
17.0K
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...
17.0K
02:54Molecular and Ionic Solids
19.5K
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...
19.5K
02:28Intermolecular Forces in Solutions
37.8K
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,...
37.8K