Magneto dielectric polymer nanocomposites and method of making

Patent metadata

Field	Value
Publication number	US-9384877-B2
Application number	US-201514685031-A
Country	US
Kind code	B2
Filing date	Apr 13, 2015
Priority date	May 27, 2010
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

In accordance with the present invention, novel superparamagnetic magneto-dielectric polymer nanocomposites are synthesized using a novel process. The tunability of the dielectric/magnetic properties demonstrated by this novel highly-viscous solvent-free polymer nanocomposite that is amenable to building 3D electromagnetic structures/devices by using processes such as 3D printing, compression molding or injection molding, when an external DC magnetic field is applied, exceeds what has been previously reported for magneto-dielectric polymer nanocomposite materials.

First claim

What is claimed is:

1. A method of preparing a superparamagnetic polymer nanocomposite material, the method comprising:
coating single-domain magnetic nanoparticles with surfactants;
dissolving a low-loss polymer and the coated magnetic nanoparticles in a solvent, wherein the solvent has a vaporizing temperature that is lower than the curing temperature of the low-loss polymer;
magnetically stirring the dissolved low-loss polymer and coated magnetic nanoparticles to obtain a dissolved low-loss polymer nanocomposite having substantially uniform dispersion;
heating the dissolved low-loss polymer nanocomposite in a vacuum oven to a temperature that is above the vaporizing temperature of the solvent and below the curing temperature of the low-loss polymer and pulsing the vacuum of the vacuum oven during the heating of the dissolved low-loss polymer nanocomposite to vaporize the dissolved low-loss polymer nanocomposite to remove the solvent, without curing the low-loss polymer nanocomposite, to obtain a solvent-free low-loss polymer nanocomposite; and
curing the solvent-free low-loss polymer nanocomposite obtain a superparamagnetic polymer nanocomposite material.

2. The method of claim 1 , wherein the single-domain magnetic nanoparticles are selected from Fe 3 O 4 nanoparticles and CoFe 2 O 4 nanoparticles.

3. The method of claim 1 , wherein the single-domain magnetic nanoparticles are Fe 3 O 4 nanoparticles having an average size of approximately 8 nm.

4. The method of claim 1 , wherein the single-domain magnetic nanoparticles are CoFe 2 O 4 nanoparticles having an average size of approximately 10 nm.

5. The method of claim 1 , wherein the surfactant is selected from oleylamine and oleic acid.

6. The method of claim 1 , wherein the solvent-free low-loss polymer contains about 25% butadiene resin.

7. The method of claim 1 , wherein the single-domain magnetic nanoparticles comprise a plurality of individual magnetic nanoparticles and wherein coating the magnetic nanoparticles with surfactants further comprises substantially encapsulating and isolating each of the individual magnetic nanoparticles.

8. The method of claim 1 , wherein the vaporizing temperature of the solvent is between about 40° C. and 50° C., under vacuum.

9. The method of claim 1 , wherein the curing temperature of the low-loss polymer is between about 100° C. and 110° C., under vacuum.

Assignees

• Weller Thomas
• Wang Jing
• Srikanth Hariharan
• Morales-Silva Cesar A
• Repa Kristen L S
• Pal Susmita
• Univ South Florida

Inventors

• Weller Thomas
• Wang Jing
• Srikanth Hariharan
• Morales-Silva Cesar A
• Repa Kristen L S
• Pal Susmita

Classifications

• H01B3/006 Primary

  Other inhomogeneous material · CPC title

• H01F41/005

  Impregnating or encapsulating (insulating of windings H01F41/12) · CPC title

• C08K9/04

  Ingredients treated with organic substances {(treated with macromolecular compounds C08K9/08)} · CPC title

• C08K2201/011

  Nanostructured additives · CPC title

• H01F1/01

  of inorganic materials (H01F1/44 takes precedence) · CPC title