Related Experiment Video
Updated: Aug 7, 2026
08:44
Assembly and Characterization of Polyelectrolyte Complex Micelles
Published on: March 2, 2020
Double electron electron resonance as a method for characterization of micelles
Sharon Ruthstein1, Alexey Potapov, Arnold M Raitsimring
1Department of Chemical Physics, Weizmann Institute of Science, Rehovot, 76100, Israel.
The Journal of Physical Chemistry. B
|July 21, 2006
Summary
Double electron electron resonance (DEER) can determine micelle properties like volume and aggregation number. This study demonstrates DEER
Area of Science:
- Colloid and Surface Science
- Polymer Chemistry
- Biophysical Chemistry
Background:
- Micelles are crucial self-assembled structures in various applications.
- Understanding micelle dimensions and aggregation is key to controlling their properties.
- Pluronic block copolymers form micelles with distinct hydrophilic and hydrophobic regions.
Purpose of the Study:
- To investigate the utility of Double Electron Electron Resonance (DEER) for characterizing micelle properties.
- To determine the volume and aggregation number of Pluronic block copolymer micelles.
- To assess the impact of Pluronic composition on micelle structure.
Main Methods:
- Utilized Double Electron Electron Resonance (DEER) spectroscopy.
- Employed the hydrophobic spin probe 4-hydroxy-tempo-benzoate (4HTB).
- Analyzed micelles of Pluronic block copolymers (L64, P123, F127) in frozen solutions.
Main Results:
- DEER successfully determined hydrophobic core radii and aggregation numbers for F127 and L64 micelles.
- Pluronic P123 micelles exhibited a rod shape, transitioning to spherical upon 4HTB addition.
- Micelle structure integrity was confirmed after rapid freezing.
Conclusions:
- DEER is a viable technique for quantifying micelle dimensions and aggregation.
- Pluronic block copolymer micelle properties are dependent on their specific PEO and PPO content.
- The study provides valuable insights into micelle self-assembly and characterization.
More Related Videos
Related Concept Videos
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...
01:17Electron Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals
Ideally, an unpaired electron shows a single peak in the EPR spectrum due to the transition between the two spin energy states. However, coupling interactions can occur between the spins of the unpaired electron and any neighboring spin-active nuclei. This hyperfine coupling results in hyperfine splitting, where the EPR signal is split into multiplets. The signals split into 2nI + 1 peaks, where n is the number of equivalent nuclei and I is the nuclear spin. These splitting patterns provide...
01:12Double Resonance Techniques: Overview
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
01:21Chemical Ionization (CI) Mass Spectrometry
The molecular ion peak of a molecule in the mass spectrum provides vital information for molecular identification. However, conventional electron impact ionization can lead to the rapid dissociation of some molecular ions before they reach the detector. A milder ionization method is required to increase the lifetime of such ionized analyte molecules. Chemical ionization (CI) is a gas-phase protonation reaction useful for mass-analyzing analyte molecules that are easily protonated to yield the...
01:20¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...