Method for preparation of various carbon allotropes based magnetic adsorbents with high magnetization

Patent metadata

Field	Value
Publication number	US-10166529-B2
Application number	US-201414215463-A
Country	US
Kind code	B2
Filing date	Mar 17, 2014
Priority date	Mar 15, 2013
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A process for the production of coating graphene, and other carbon allotropes, onto carbon-coated magnetic nanoparticles while maintaining high magnetic moment and adsorption properties is disclosed.

First claim

What I claim is:

1. A method for producing carbon allotrope-coated magnetic particles comprising:
providing a magnetic metal-containing precursor;
heating the magnetic metal-containing precursor in a furnace to form a plurality of individual carbon-coated magnetic particles;
collecting the plurality of individual carbon-coated magnetic particles from the furnace;
treating the plurality of individual carbon-coated magnetic particles with sonic energy in a sonication reactor to de-agglomerate the plurality of individual carbon-coated magnetic particles; and
after the treating of the plurality of individual carbon-coated magnetic particles with the sonic energy, removing the carbon-coated magnetic particles from the sonication reactor, and then contacting each of the plurality of individual carbon-coated magnetic particles with carbon allotropes in a vessel,
for a time sufficient so as to obtain a plurality of individual carbon allotrope-coated carbon-coated magnetic particles having a magnetization from 20 emu/g to 140 emu/g and surface area from 200 m 2 /g to 1000 m 2 /g,
wherein the carbon allotropes are selected from the group consisting of graphene, graphene oxide, graphite, graphite oxide, carbon fiber, activated carbon, and carbon nanotubes, and
wherein the plurality of individual carbon-coated magnetic particles and the carbon allotropes are independent from each other and do not interact with each other until they are contacted with one another.

2. The method according to claim 1 , wherein the magnetic metal comprises one or more metal selected from the group consisting of iron, cobalt, nickel, gadolinium, neodymium, and samarium.

3. The method according to claim 1 , wherein the magnetic metal comprises iron.

4. The method according to claim 1 , wherein the magnetic metal-containing precursor comprises ferrocene.

5. The method according to claim 1 , wherein the plurality of individual carbon allotrope-coated carbon-coated magnetic particles comprises particles having a particle size ranging from 20 nm to 100 nm.

6. The method according to claim 1 , wherein the plurality of individual carbon allotrope-coated carbon-coated magnetic particles comprise particles having magnetization of at least 40 emu/g.

7. The method according to claim 1 , wherein the plurality of individual carbon allotrope-coated carbon-coated magnetic particles are substantially free of iron oxides and iron carbides.

8. A method for producing carbon allotrope-coated ferromagnetic particles comprising:
providing an iron-containing precursor;
heating the iron-containing precursor in a furnace to form a plurality of individual carbon-coated iron magnetic particles;
collecting the plurality of individual carbon-coated iron magnetic particles from the furnace:
treating the plurality of individual carbon-coated iron magnetic particles with sonic energy in a sonication reactor to de-agglomerate the plurality of individual carbon-coated iron magnetic particles; and
after the treating of the plurality of individual carbon-coated iron magnetic particles with the sonic energy, removing the carbon-coated magnetic particles from the sonication reactor, and
then contacting the plurality of individual carbon-coated iron magnetic particles with carbon allotropes in a vessel,
for a time sufficient so as to obtain a plurality of individual carbon allotrope-coated carbon-coated iron magnetic particles having a magnetization from 20 emu/g to 140 emu/g and surface area from 200 m2/g to 1000 m2/g,
wherein the carbon allotropes are selected from the group consisting of graphene, graphene oxide, graphite, graphite oxide, carbon fiber, activated carbon, and carbon nanotubes, and
wherein the plurality of individual carbon-coated iron magnetic particles and the carbon allotropes are independent from each other and do not interact with each other until they are contacted with one another.

9. The method according to claim 8 , wherein the iron-containing precursor comprises ferrocene.

10. The method according to claim 8 , wherein the plurality of individual carbon allotrope-coated carbon-coated magnetic particles comprises particles having a particle size ranging from 20 nm to 100 nm.

11. The method according to claim 8 , wherein the plurality of individual carbon allotrope-coated carbon-coated iron magnetic particles comprise particles having magnetization of at least 40 emu/g.

12. The method according to claim 8 , wherein the plurality of individual carbon allotrope-coated carbon-coated iron magnetic particles are substantially free of iron oxides and iron carbides.

Assignees

• Honda Motor Co Ltd

Inventors

• Harutyunyan Avetik

Classifications

• B82Y25/00

  Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance · CPC title

• B01J20/3289

  Coatings involving more than one layer of same or different nature · CPC title

• B01J20/28009

  Magnetic properties · CPC title

• H01F1/0054

  Coated nanoparticles, e.g. nanoparticles coated with organic surfactant · CPC title

• B01J20/3078

  Thermal treatment, e.g. calcining or pyrolizing · CPC title