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Driving self-assembly and emergent dynamics in colloidal suspensions by time-dependent magnetic fields
James E Martin1, Alexey Snezhko
1Sandia National Laboratories, Albuquerque, NM 87185, USA.
Reports on Progress in Physics. Physical Society (Great Britain)
|November 6, 2013
Summary
Researchers explore self-assembly of magnetic particles using alternating magnetic fields. This review covers diverse structures, dynamic behaviors, and novel material properties driven by these fields in suspensions and at interfaces.
Area of Science:
- Physics
- Materials Science
- Soft Matter Physics
Background:
- Magnetic particle suspensions offer a versatile platform for studying self-assembly.
- Alternating magnetic fields provide a powerful external stimulus to control particle behavior.
- The complexity of particle shapes, field configurations, and confinement influences assembly outcomes.
Purpose of the Study:
- To review recent advancements in the driven self-assembly of magnetic particle suspensions.
- To explore the diverse structures and emergent behaviors induced by alternating magnetic fields.
- To highlight the properties of novel materials formed through these self-assembly processes.
Main Methods:
- Utilizing alternating magnetic fields (uniaxial, biaxial, triaxial) to drive particle assembly.
- Investigating spherical and anisometric magnetic particles.
- Examining suspensions in bulk fluids and at soft interfaces (air-liquid, liquid-liquid).
Main Results:
- Formation of static/quasistatic structures like sheets, networks, and foams.
- Emergence of complex collective behaviors and flow patterns (advection, vortex lattices) in bulk fluids.
- Development of dynamic interfacial assemblies with phenomena like self-propulsion and surface mixing.
Conclusions:
- Alternating magnetic fields enable a broad range of self-assembled structures and dynamic phenomena in magnetic suspensions.
- Out-of-equilibrium interfacial assemblies exhibit remarkable properties, including active behaviors.
- This field offers pathways to novel functional materials through controlled self-organization.
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