Related Experiment Video
Updated: Apr 15, 2026
10:23
Synthesis of Cationized Magnetoferritin for Ultra-fast Magnetization of Cells
Published on: December 13, 2016
10.6K
Bioinspired magnetite formation from a disordered ferrihydrite-derived precursor
Archan Dey1, Jos J M Lenders, Nico A J M Sommerdijk
1Laboratory of Materials and Interface Chemistry and Soft Matter CryoTEM Research Unit, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands. N.Sommerdijk@tue.nl.
Faraday Discussions
|April 14, 2015
Summary
Researchers discovered a new bioinspired method for synthesizing magnetite nanocrystals. This process involves ferrihydrite and Fe(II) ions, bypassing green rust with a polypeptide additive for controlled nucleation.
Area of Science:
- Mineralogy
- Materials Science
- Biomineralization
Background:
- Magnetite (Fe3O4) is a technologically important mineral with diverse geological and biological roles.
- Understanding magnetite nucleation is crucial for both natural processes and synthetic applications.
- Current synthesis methods often lack control over particle size and morphology.
Purpose of the Study:
- To elucidate the multi-step nucleation process of magnetite formation from ferrihydrite and Fe(II) ions.
- To investigate the role of intermediate phases, such as green rust, in magnetite crystallization.
- To explore the impact of additives, like polypeptides, on the synthesis pathway and final product.
Main Methods:
- Reacting ferrihydrite (FeH) with Fe(II) ions under controlled pH conditions.
- Utilizing advanced microscopy and spectroscopy to characterize intermediate phases and final products.
- Comparing synthesis routes with and without a polypeptide additive.
Main Results:
- Magnetite formation proceeds via a multi-step nucleation involving FeH-Fe(II) primary particles.
- A transient green rust phase acts as an intermediate, leading to secondary particles for magnetite.
- A polypeptide additive inhibits green rust formation, promoting amorphous FeH-Fe(II) aggregates that transform into magnetite nanocrystals.
Conclusions:
- The study reveals a novel bioinspired crystallization route for magnetite.
- The findings highlight the importance of disordered precursor phases and intermediate transitions in magnetite nucleation.
- This research offers insights into magnetite formation in natural systems and suggests new avenues for sustainable synthesis.
Related Concept Videos
01:31Ferromagnetism
3.6K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
3.6K
01:24Microbes and Other Elemental Cycles
71
Microbial activity plays a pivotal role in the biogeochemical cycling of iron and manganese, especially at the redox gradients characteristic of stratified aquatic environments. These cycles are driven by microbial transformations between oxidized and reduced forms of the metals, allowing organisms to exploit them for metabolic energy and structural purposes.Iron Cycling Across Redox GradientsIn neutral, oxygen-rich surface waters, iron is predominantly found in its oxidized, insoluble ferric...
71
01:18Other Unique Bacteria
557
Magnetic bacteria exhibit a directed movement called magnetotaxis, driven by structures called magnetosomes. These magnetosomes consist of chains of magnetic particles made of either magnetite (Fe₃O₄) or greigite (Fe₃S₄) and are organized in a linear conformation by a protein scaffold within invaginations of the cell membrane. The bacteria align along the north–south magnetic field lines, much like a compass needle. They are typically microaerophilic or anaerobic...
557
01:26Diamagnetism
3.5K
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
3.5K
03:02Colors and Magnetism
14.8K
Color in Coordination Complexes
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...
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...
14.8K
01:30Magnetism
10.1K
Magnets are commonly found in everyday objects, such as toys, hangers, elevators, doorbells, and computer devices. Experimentation on these magnets shows that all magnets have two poles: one is labeled north (N) and the other south (S). Magnetic poles repel if they are alike and attract if unlike. Moreover, both poles of a magnet attract unmagnetized pieces of iron.
An individual magnetic pole cannot be isolated. No matter how small, every piece of a magnet contains a north pole and a south...
An individual magnetic pole cannot be isolated. No matter how small, every piece of a magnet contains a north pole and a south...
10.1K