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US 2022/0093295 A1Published application
Magnetic beads, method of making and method of use thereof
AssigneeNanophase Technologies Corporation
InventorsHarry W. Sarkas, Kevin Cureton
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Abstract
Magnetic beads comprise a plurality of magnetic nanoparticles, dispersed in a non-magnetic matrix. The magnetic beads have an average particle size of 0.1 μm to 100 μm. The matrix may comprise an inorganic metal oxide or a polymer. The magnetic beads have a specific surface area of at least 40 m2/g.
Claims20
Magnetic beads, comprising:
- (i) a plurality of magnetic nanoparticles, dispersed in (ii) a non-magnetic inorganic oxide matrix,
- wherein the magnetic beads have an average particle size of 0.1 μm to 100 μm, the magnetic nanoparticles have an average particle size of 20 nm to 50 nm,
- the non-magnetic inorganic oxide matrix contains neither Group I nor Group II elements, and does not contain boron, and
- the magnetic beads contain at least 75% by weight of the plurality of magnetic nanoparticles, and retain a saturation magnetization of at least 75% of the bulk saturation of the magnetic nanoparticles, based on the weight of the magnetic beads.
1 more element
Magnetic beads, comprising:
- (i) a plurality of magnetic nanoparticles, dispersed in (ii) a non-magnetic inorganic oxide matrix,
- wherein the magnetic beads have an average particle size of 0.1 μm to 100 μm,
- the magnetic nanoparticles have an average particle size of 20 nm to 50 nm,
- the magnetic beads have a specific surface area of at least 40 m2/g, and
- the magnetic beads contain at least 75% by weight of the plurality of magnetic nanoparticles, and retain a saturation magnetization of at least 75% of the bulk saturation of the magnetic nanoparticles, based on the weight of the magnetic beads.
2 more elements
Magnetic beads, comprising:
- (i) a plurality of magnetic nanoparticles, dispersed in (ii) a polymer matrix,
- wherein the magnetic beads have an average particle size of 0.1 μm to 100 μm, and
- the polymer matrix does not contain moieties of a PEG functionalized surfactant.
A method of making magnetic beads, comprising:
- forming a solid dispersion comprising magnetic nanoparticles dispersed in a matrix;
- and
- grinding the solid dispersion, to form magnetic beads having an average particle size of 0.1 μm to 100 μm.
Dependencies are inferred from the claim text.