Related Experiment Video
Updated: Aug 3, 2026
10:53
Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by π-π Stacking Interactions
Published on: October 10, 2016
The Structure of Nonionic Micelles in Less Polar Solvents
1Rutherford Appleton Laboratory, ISIS Facility, Chilton, Didcot, Oxon, United Kingdom
Journal of Colloid and Interface Science
|January 15, 1997
Summary
Small angle neutron scattering reveals how solvent polarity affects nonionic micelle structure. Adding glycerol or sorbitol to water changes micelle size, shape, and flexibility, impacting their behavior in solution.
Area of Science:
- Colloid and Surface Chemistry
- Materials Science
- Physical Chemistry
Background:
- Nonionic surfactants form micelles in solution, whose properties are sensitive to solvent composition and temperature.
- Understanding micelle structure and behavior is crucial for applications in detergency, drug delivery, and materials self-assembly.
Purpose of the Study:
- To investigate the structural and geometrical changes of nonionic micelles (C12EO8, C12EO6, C16EO8) in less polar solvents.
- To determine the influence of glycerol, sorbitol, and ethylene glycol on micelle aggregation number, headgroup hydration, and shape.
Main Methods:
- Small angle neutron scattering (SANS) was employed to probe micelle structure.
- Couette shear flow alignment was used in conjunction with SANS for specific micelle systems.
Main Results:
- In glycerol/water mixtures, increasing glycerol content increased micelle aggregation number and decreased headgroup hydration for C12EO8.
- Micelle size increased with glycerol addition, linked to headgroup dehydration and proximity to the lower consolute boundary.
- Sorbitol or glycerol addition to C16EO8/water mixtures resulted in less anisotropic, more labile micelles, exhibiting flexibility and shear-induced transformations.
Conclusions:
- Solvent composition significantly impacts nonionic micelle structure and dynamics.
- Dehydration of ethylene oxide headgroups plays a key role in micelle behavior changes with solvent polarity and temperature.
- Micelles exhibit complex responses to shear, including shape changes and increased flexibility, depending on the surfactant and solvent system.
Related Concept Videos
03:37Molecular Shape and Polarity
Dipole Moment of a Molecule
03:22Colloids
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...
03:00Solubility
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, atoms, and/or ions)...
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, atoms, and/or ions)...
02:05Entropy and Solvation
The process of surrounding a solute with solvent is called solvation. It involves evenly distributing the solute within the solvent. The rule of thumb for determining a solvent for a given compound is that like dissolves like. A good solvent has molecular characteristics similar to those of the compound to be dissolved. For example, polar solutions dissolve polar solutes, and apolar solvents dissolve apolar solutes. A polar solvent is a solvent that has a high dielectric constant (ϵ ≥ 15); an...
01:29The Colloidal State
The formation of a colloidal system is exemplified by an aqueous solution containing Cl− ions is introduced to another containing Ag+ ions, resulting in the precipitation of solid AgCl as extremely tiny crystals. Instead of settling out as a filterable precipitate, these crystals remain suspended in the liquid, showcasing a colloidal system.A colloidal system involves colloidal particles within the approximate range of 1 to 1000 nm in at least one dimension, dispersed in a medium called the...
01:30Micelles
Micelle formation is an intricate process that hinges on the properties of amphiphilic or amphipathic molecules and the conditions of the system in which they are found. Amphiphilic molecules, which have both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts, play a critical role in this process.In aqueous environments, these molecules arrange themselves such that their hydrophilic heads are turned towards the water phase, while their hydrophobic tails are oriented away...