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We report the effect of shape anisotropy and material properties on the directed assembly of binary suspensions composed of magnetizable ellipsoids. In a Monte Carlo simulation, we implement the ellipsoid-dipole model to calculate the pairwise dipolar interaction energy as a function of position and orientation. The analysis explores dilute suspensions of paramagnetic and diamagnetic ellipsoids with different aspect ratios in a superparamagnetic medium. We analyze the local order of binary structuresas a function of particle aspect ratio, medium permeability, and dipolar interaction strength. Our results show that local order and symmetry are tunable under the influence of a uniform magnetic field when one component of the structure is dilute with respect to the other. The simulation results match previously reported experiments on the directed assembly of binary suspension of spheres. Additionally, we report the conditions on particle aspect ratios and medium properties for various structures with rotational symmetries, as well as open and enclosed structures under the influence of a uniform magnetic field.
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This content will become publicly available on October 8, 2026
Directed assembly of binary suspensions of magnetizable ellipsoids
We investigate the effect of particle anisotropy and magnetic properties on the directed assembly of binary suspensions of magnetizable ellipsoids in a two-dimensional confinement. A suspension of paramagnetic spheres and diamagnetic ellipsoids in a superparamagnetic medium is subjected to a uniform magnetic field that is perpendicular to the assembly plane. We implement the ellipsoid-dipole model in a Monte-Carlo simulation to analyze the effects of particle aspect ratio, medium permeability, and relative particle concentrations on the assembly of binary suspensions of ellipsoids. We validate the simulations by comparing the orientational symmetry of binary structures of magnetizable spheres with previously reported experiments. Simulation results for a binary suspension of paramagnetic and diamagnetic spheres show structures with tunable orientational symmetry as medium permeability increases. Additionally, the results for the directed assembly of paramagnetic spheres and diamagnetic ellipsoids show tunable open-packed triangular enclosures and interconnected chain-like structures with different local order. The simulation results show the potential for customizing the assembled structures by tuning both medium and particle magnetic properties in binary colloidal suspensions.
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- Award ID(s):
- 2338064
- PAR ID:
- 10652658
- Publisher / Repository:
- Soft Matter
- Date Published:
- Journal Name:
- Soft Matter
- Volume:
- 21
- Issue:
- 39
- ISSN:
- 1744-683X
- Page Range / eLocation ID:
- 7662 to 7672
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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