Related Experiment Video
Updated: Jan 23, 2026
10:42
Pretreatment of Lignocellulosic Biomass with Low-cost Ionic Liquids
Published on: August 10, 2016
18.9K
DTAB micelle formation in ionic liquid/water mixtures is determined by ionic liquid cation structure.
Minh T Lam1, William D Adamson1, Shurui Miao1
1School of Chemistry and University of Sydney Nano Institute, The University of Sydney, NSW 2006, Australia.
Journal of Colloid and Interface Science
|June 5, 2019
Summary
Ionic liquids (ILs) influence micelle formation differently than expected. Mixing ILs with water alters critical micelle concentration (CMC) and micelle shape by incorporating IL cations into micelles, impacting surfactant behavior.
Area of Science:
- Physical Chemistry
- Supramolecular Chemistry
- Materials Science
Background:
- Ionic liquids (ILs) exhibit unique properties due to their ionic nature and nanostructure.
- The behavior of surfactants in ILs deviates from that in aqueous solutions, presenting a challenge in understanding micellization.
- Controlling micelle formation is crucial for applications in drug delivery, catalysis, and nanotechnology.
Purpose of the Study:
- To investigate the effect of mixing ionic liquids (ILs) with water on the critical micelle concentration (CMC) and micelle morphology of dodecyltrimethylammonium bromide (DTAB).
- To elucidate the role of ILs' amphiphilic nanostructure and cation incorporation in driving micellization.
- To compare the behavior of IL-water mixtures with traditional aqueous electrolytes.
Main Methods:
- Determined CMCs and micelle sizes of DTAB in water-IL mixtures (EAN, EtAN, PAN) across a wide composition range.
- Utilized various techniques to determine CMCs and critically evaluated their strengths.
- Employed small-angle neutron scattering (SANS) to determine micelle morphology.
Main Results:
- In water-rich mixtures, ILs act as simple electrolytes, lowering CMC and promoting sphere-to-rod transitions.
- IL cations incorporate into micelles at moderate concentrations, causing a CMC minimum and halting sphere-rod transitions.
- At higher IL concentrations, IL nanostructure increases alkyl chain solubility, raising the CMC.
Conclusions:
- The amphiphilic nanostructure of ILs, not just their ionic strength, dictates micellization behavior.
- Mixing ILs with water offers a tunable environment to control surfactant self-assembly.
- Understanding these interactions is key to designing novel IL-based solvent systems for tailored micellar properties.
Related Concept Videos
02:42Ionic Crystal Structures
16.9K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
16.9K
03:10Ionic Radii
33.3K
Ionic radius is the measure used to describe the size of an ion. A cation always has fewer electrons and the same number of protons as the parent atom; it is smaller than the atom from which it is derived. For example, the covalent radius of an aluminum atom (1s22s22p63s23p1) is 118 pm, whereas the ionic radius of an Al3+ (1s22s22p6) is 68 pm. As electrons are removed from the outer valence shell, the remaining core electrons occupying smaller shells experience a greater effective nuclear...
33.3K
00:42Ionic Bonds
129.5K
Overview
When atoms gain or lose electrons to achieve a more stable electron configuration they form ions. Ionic bonds are electrostatic attractions between ions with opposite charges. Ionic compounds are rigid and brittle when solid and may dissociate into their constituent ions in water. Covalent compounds, by contrast, remain intact unless a chemical reaction breaks them.
Opposing Charges Hold Ions Together in Ionic Compounds
Ionic bonds are reversible electrostatic interactions between ions...
When atoms gain or lose electrons to achieve a more stable electron configuration they form ions. Ionic bonds are electrostatic attractions between ions with opposite charges. Ionic compounds are rigid and brittle when solid and may dissociate into their constituent ions in water. Covalent compounds, by contrast, remain intact unless a chemical reaction breaks them.
Opposing Charges Hold Ions Together in Ionic Compounds
Ionic bonds are reversible electrostatic interactions between ions...
129.5K
02:54Molecular and Ionic Solids
20.0K
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...
20.0K
02:48Ionic Bonding and Electron Transfer
48.9K
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
48.9K
03:34Ionic Compounds: Formulas and Nomenclature
86.3K
An element composed of atoms that readily lose electrons (a metal) can react with an element composed of atoms that readily gain electrons (a nonmetal) to produce ions through complete electron transfer. The compound formed by this transfer is stabilized by the electrostatic attractions (ionic bonds) between the oppositely charged ions.
86.3K