Claims
- 1. A composition of matter: said composition comprising; magnetic nanoparticle compositions having shell/core structures.
- 2. The composition of claim 1.; wherein said magnetic nanoparticles have a diameter range of up to about 100 nm.
- 3. The composition of claim 1.; wherein said shell has a thickness of up to about 10 nm.
- 4. The composition of claim 1.; wherein said magnetic nanoparticles are passivated magnetic nanoparticles.
- 5. The composition according to claim 1.; where said core is selected from the group consisting of; iron, cobalt, nickel, or alloys thereof or equivalents thereof.
- 6. The composition of claim 1.; wherein said shell is selected from the group consisting of: group 6 or group 8 transition metal oxides.
- 7. The composition of claim 6.; wherein said metal oxides are selected from the group consisting of: the oxides of chromium, molybdenum, tungsten, iron, cobalt, or nickel or equivalents thereof.
- 8. A composition of matter: said composition comprising; passivated magnetic nanoparticles having a shell and core structure with a diameter of up to about 100 nm, and a shell thickness of up to about 10 nm.
- 9. A composition of matter according to claim 8.; wherein said core is iron and said shell is selected from the group consisting of: the oxides of chromium, molybdenum, tungsten, iron, cobalt, or nickel or equivalents therof.
- 10. A method of making passivated shell/core magnetic nanoparticle compositions; comprising the steps of:
(1) making compositions comprising:
(a) aqueous metal salt solutions for making said core; (b) aqueous metal salt solutions for making said shell; (c) aqueous sodium borohydride solutions for reducing said metal salts in solutions (a) and (b); (d) surfactants dissolved in organic solvents; (2) making said core by mixing solutions (a), (c), and (d) above; (3) making said shell by mixing solutions (b), (c), and (d) above; (4) making said shell/core composition by mixing (2) and (3) above and passivating said product thereof by exposure to an oxidizing medium.
- 11. The method of claim 10; wherein said core metal is selected from the group consisting of iron, cobalt, or nickel, or alloys thereof or equivalents thereof.
- 12. The method of claim 10, wherein said shell is selected from the group consisting of; group 6 or group 8 transition metal oxides.
- 13. The method of claim 10; wherein said metal oxides are selected from the group consisting of: the oxides of chromium, molybdenum, tungsten, iron cobalt, or nickrl or equivalents thereof.
- 14. The method of claim 10; wherein said passivated nanoparticle composition has a diameter of up to about 50 nm.
- 15. The method of claim 10; wherein said shell has a diameter of up to about 10 nm.
- 16. The method of claim 10; wherein said surfactants are selected from the group consisting of: trialkylammonium salts, nonylphenolpolyethoxylates, sodium dodecylbenzenesulfonates, or bis (2-ethylhexyl)sulfosuccinate ester.
- 17. The method of claim 16, wherein said surfactant is selected from the group consisting of: cetyltrimethylammonium bromide or nonylphenolpolyethoxylate 4 or 7.
Parent Case Info
[0001] This patent application is based on provisional U.S. patent application serial No. 60/370,693 filed Apr. 9, 2002.
Provisional Applications (1)
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Number |
Date |
Country |
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60370693 |
Apr 2002 |
US |