Related Experiment Video
Updated: Feb 14, 2026
Magnetic and Thermal-sensitive PolyN-isopropylacrylamide-based Microgels for Magnetically Triggered Controlled Release
Published on: July 4, 2017
Tunable clustering of magnetic nanoparticles in microgels: enhanced magnetic relaxivity by modulation of network
1DWI Leibniz Institute for Interactive Materials e.V., Forckenbeckstr. 50, Aachen, 52074, Germany.
Abstract:
In the present work we used microgels as colloidal containers for the loading of hydrophobic magnetic nanoparticles using the solvent exchange method. We varied systematically two parameters: (i) the crosslinking degree of microgels (1-4.5 mol% crosslinker) and (ii) loading of hydrophobic magnetite nanoparticles (d = 7 nm) in microgels (2-10 wt%). The experimental data show that the interplay between these two parameters provides efficient control over the clustering of magnetic nanoparticles in the microgel structure. Transverse magnetization relaxation measurements indicate that the formation of nanoparticle clusters in microgels induces non-linear enhancement of the relaxivity with the increase of nanoparticle loading in microgels. The results suggest that the modulation of the microgel network architecture can be efficiently applied to trigger self-assembly processes inside microgels and design hybrid colloids with unusual morphologies and properties.
Related Concept Videos
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
01:30Magnetism
An individual magnetic pole cannot be isolated. No matter how small, every piece of a magnet contains a north pole and a south...
01:18Magnetic Flux
Suppose a surface is divided into elements of area dA. For each element, the component of the magnetic field that is normal to the...
01:17Magnetic Damping
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
01:19Magnetic Declination
01:18Magnetic Force
The magnetic force acting on a moving charge...