Related Experiment Video
Updated: May 20, 2025
08:05
Microtensiometer for Confocal Microscopy Visualization of Dynamic Interfaces
Published on: September 9, 2022
2.3K
Molecular insights: How counterions determine surfactant aggregation
Lili Zhou1, Zhang Liu2, Yilin Wang3
1School of Light Industry Science and Engineering, Beijing Technology and Business University, Beijing 100048, PR China.
Advances in Colloid and Interface Science
|March 29, 2025
Summary
Choosing the right counterion is key to controlling surfactant aggregate morphology and function. This review details how counterions influence structures like micelles and vesicles for tailored applications.
Area of Science:
- Colloid and Surface Science
- Materials Chemistry
Background:
- Surfactant aggregate morphology dictates properties and applications.
- Controlling morphology is crucial for advanced material design.
Purpose of the Study:
- To review the fundamental principles of how counterions influence ionic surfactant aggregation.
- To provide guidance on selecting counterions for desired aggregate structures.
Main Methods:
- Comprehensive literature review on counterion effects in surfactant systems.
- Analysis of factors like charge, polarizability, and hydrophobicity of counterions.
Main Results:
- Counterions (inorganic and organic) significantly modulate surfactant aggregation.
- Diverse aggregate structures (spherical micelles, wormlike micelles, vesicles, coacervates) are formed.
- Counterion properties critically influence headgroup charge neutralization and hydrophobic interactions.
Conclusions:
- Counterion selection is an efficient strategy for tailoring surfactant aggregate morphology.
- Understanding counterion-surfactant interactions enables precise control over material properties.
Related Concept Videos
03:24Common Ion Effect
40.8K
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Châtelier’s principle. Consider the dissolution of silver iodide:
40.8K
01:19Ionic Strength: Effects on Chemical Equilibria
1.3K
The addition of an inert ionic compound increases the solubility of a sparingly soluble salt. For example, adding potassium nitrate to a saturated solution of calcium sulfate significantly enhances the solubility of calcium sulfate. Le Châtelier's principle cannot predict this shift in the equilibrium. Instead, this could be explained in terms of changes in the effective concentration of the ions in solution in the presence of added inert salt.
In this solution, the primary...
In this solution, the primary...
1.3K
01:09Colloidal precipitates
468
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
468
01:17Factors Affecting Activity Coefficient
705
The extended Debye-Hückel equation indicates that the activity coefficient of an ion in an aqueous solution at 25°C depends on three partially interdependent properties: the ionic strength of the solution, the charge of the ion, and the ion size.
The activity coefficient value for an ion is close to one when the solution has almost zero ionic strength, i.e., when the solution shows close to ideal behavior. As the ionic strength of the solution increases from 0 to 0.1 mol/L, a...
The activity coefficient value for an ion is close to one when the solution has almost zero ionic strength, i.e., when the solution shows close to ideal behavior. As the ionic strength of the solution increases from 0 to 0.1 mol/L, a...
705
03:45Formation of Complex Ions
23.1K
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
23.1K
03:22Colloids
17.2K
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles that are visible to the naked eye or can be seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. On the other hand, a solution is a homogeneous mixture in which no settling occurs and in which the dissolved...
17.2K