Graphite encapsulated nanophase particles produced by a tungsten arc method
AssigneeNorthwestern University
InventorsVinayak P. Dravid, Mao-Hua Teng, Jonathon J. Host, Brian R. Elliott, D. Lynn Johnson, Thomas O. Mason, Julia R. Weertman, J.-H. Hwang
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Abstract
A method of synthesizing encapsulated nanocrystals inside protective shells is disclosed. This method produces nanocrystals of metals, alloys, and compounds which are individually encapsulated by protective graphite shells which completely separate the nanocrystals from the environment. A separation method is also disclosed which eliminates most of all other debris except the encapsulated nanocrystals from the preparation product.
Claims12
A method of producing graphite encapsulated nanocrystals, comprising the steps of:
- a) setting up a tungsten cathode to be spaced from an anode formed of a metal, alloy or ceramic compound, said anode having magnetic or electronic properties, and held in a graphite crucible within an arc chamber;
- b) filling said arc chamber with an inert gas;
- c) providing an electric arc between said cathode and said anode;
- d) creating particles of said metal in nanocrystalline form encapsulated by said graphite;
- e) collecting said particles;
- and
- f) washing and separating said particles.
A method of producing graphite encapsulated nickel nanocrystals comprising the steps of:
- a) setting up a tungsten cathode spaced from a nickel anode in a graphite crucible;
- said cathode, anode and crucible being in an arc chamber;
- b) filling said arc chamber with He;
- c) creating an arc in said arc chamber with about 20 DC volts and about 130 amps of current;
- d) directing a stream of He at said arc at a velocity of between 20-60 m/s and creating a pressure of 200 torr in said arc chamber;
- and,
- e) depositing, collecting and separating said graphite encapsulated nickel nanocrystals.
Dependencies are inferred from the claim text.