CONTROL OF MATERIALS AND POROUS MAGNETIC PARTICLES

• US 20090179171A1
• Filed: 05/16/2007
• Published: 07/16/2009
• Est. Priority Date: 07/19/2004
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Segal, Ester, Sailor, Michael J., Vecchio, Kenneth S., Bhatia, Sangeeta N., Park, Ji-Ho, Derfus, Austin M.
• Granted Patent: US 8,377,147 B2
• Time in Patent Office: Days
• US Class Current: 252/62.51R
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: H01F 1/0063 in a non-magnetic matrix, e.g. granular solids granular films H01F10/007
• CPC Class Codes: H05B 6/02 Induction heating
• CPC Class Codes: Y10T 428/29 Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/32 Composite [nonstructural laminate] of inorganic material having metal-compound-containing layer and having defined magnetic layer

Abstract

The present invention uses externally applied electromagnetic stimulus to control and heat porous magnetic particles and material associated with the particles. The particles contain magnetic material, such as superparamagnetic iron oxide and are associated with a material. Application of a DC magnetic field allows them to be moved with their associated material, and application of an AC RF electromagnetic field allows them to be heated with their associated material. The material can be associated with the particles by being contained in the pores of the particles, or in other cases the particles can adhere to the associated material, which can be an aqueous droplet. The present invention also provides a multi-layer porous magnetic particle. The particle includes a host layer having pores sized to accept magnetic nanoparticles. Magnetic nanoparticles are infused within pores of the host layer An encoding layer includes pores that define a spectral code. The pores in the encoding layer are sized to substantially exclude the magnetic nanoparticles. The encoding layer can also be a multi-layer, exhibiting, for example, a complex spectral code.

Claims

1. A method for control of associated material, the method comprising steps of:

providing a porous microparticle with magnetic material within its pores;

associating the associated material with the porous microparticle;

with an external magnetic field, controlling the porous microparticle to thereby control the associated material.

2. The method of claim 1, wherein said step of controlling comprises applying an AC radio frequency electromagnetic field to heat the porous microparticles and thereby heat the associated material.

3. The method of claim 2, wherein the porous microparticles comprises multiple porous layers, a first layer containing a spectral code and a second layer hosting the magnetic material.

4. The method of claim 3, wherein said step of associating comprises infusing the associated material into the pores of the second layer.

5. The method of claim 2, wherein said step of associating comprises adhering the porous microparticle to an aqueous droplet.

6. The method of claim 1, wherein the porous microparticles comprises multiple porous layers, a first layer containing a spectral code and a second layer hosting the magnetic material.

7. The method of claim 1, wherein said step of controlling comprises applying a DC magnetic field to move the particles and thereby move the associated material.

8. The method of claim 7, wherein said step of associating comprises infusing the associated material into the pores of the porous microparticle.

9. The method of claim 7, wherein said step of associating comprises adhering the porous microparticle to an aqueous droplet.

10. The method of claim 7, wherein the porous microparticles comprises multiple porous layers, a first layer containing a spectral code and a second layer hosting the magnetic material.

11. A magnetic porous particle, comprising:

a host layer having pores sized to accept magnetic nanoparticles;

magnetic nanoparticles infused within pores of the host layer;

an encoding layer having pores that define a spectral code, the pores in the encoding layer being sized to substantially exclude the magnetic nanoparticles.

12. The particle of claim 11, wherein the encoding layer comprises multiple layers that exhibit a complex spectral code.

13. The particle of claim 11, wherein the magnetic particles comprises superparamagnetic particles.

14. The particle of claim 11, wherein the pores of the encoding layer are sized to accept infusion of an associated material smaller than the magnetic nanoparticles.