Electrically conductive nanocomposite material

• US 9,287,023 B2
• Filed: 01/23/2013
• Issued: 03/15/2016
• Est. Priority Date: 04/17/2002
• Status: Active Grant

• Current Assignee: Conductive Composites Company, LLC
• Original Assignee: Conductive Composites Company, LLC
• Inventors: Hansen, George Clayton, Hansen, Nathan D., Hansen, Lauren
• Primary Examiner(s): Nguyen, Khanh Tuan
• Application Number:
  US13/747,647
• Publication Number:
  US 20130134364A1
• Time in Patent Office: 1,147 Days
• Field of Search: 252/62.54, 428/294.4, 428/295.1, 428/605, 501/35
• US Class Current: 1/1
• CPC Class Codes: B29C 70/14 oriented
• CPC Class Codes: B29C 70/882 partly or totally electrically conductive, e.g. for EMI shielding conductive floors or floor coverings H05F3/025; EMI shielding in general H05K9/00
• CPC Class Codes: D04H 3/002 Inorganic yarns or filaments
• CPC Class Codes: D04H 5/00 Non woven fabrics formed of mixtures of relatively short fibres and yarns or like filamentary material of substantial length
• CPC Class Codes: H01B 13/00 Apparatus or processes specially adapted for manufacturing conductors or cables
• CPC Class Codes: Y10T 428/249931 Free metal or alloy fiber
• CPC Class Codes: Y10T 428/249933 Fiber embedded in or on the surface of a natural or synthetic rubber matrix

Abstract

An electromagnetically active composite has an electrically-nonconductive host matrix and electrically-conductive nanostrand bodies embedded in a substantially uniform distribution throughout the host matrix. Each of the nanostrand bodies comprises a volume containing at least one nanostrand of filamentary metal. Adjacent nanostrand bodies that are sufficiently mutually proximate will interact electromagnetically with each other. The filamentary metal of the one or more nanostrands in each of the nanostrand bodies occupies a deminimus fraction of the overall volume occupied by the at least one nanostrand that comprises each of the nanostrand bodies. The filamentary metal is chosen from among the group of metals that includes nickel, nickel aluminides, iron, iron aluminides, alloys of nickel and iron, and alloys of nickel and copper. Individual nanostrands of the nanostrand bodies have an average diameter in a range of from about 10 nanometers to about 4000 nanometers, and the average diameter of the nanostrand bodies is in a range of from about one micron to about 3000 microns.

Claims

1. A method for imparting electromagnetic activity to an electrically-nonconductive host matrix, the method comprising the steps of:

forming open structure, electrically-conductive nanostrand bodies, the nanostrand bodies comprise branched, three-dimensional, open chains;

combining said nanostrand bodies with the host matrix; and

distributing said nanostrand bodies uniformly throughout the host matrix with adjacent of said nanostrand bodies being sufficiently mutually proximate to interact electromagnetically, and the open chains of the nanostrand bodies remain uncollapsed following the step of combining and the step of distributing.

2. A method as recited in claim 1, further comprising the step of minimizing shear forces imposed on said nanostrand bodies by the host matrix, the step of minimizing shear forces comprises at least one of lowering viscosity of the host matrix and controlling the shear velocity of the host matrix.

3. A method as recited in claim 2, wherein said step of lowering viscosity of the host matrix comprises at least one of increasing temperature of the host matrix and adding a solvent to the host matrix.

4. A method as recited in claim 2, wherein said step of controlling shear velocity comprises at least one of controlling mixing time and controlling mixing speed dependent on the volume of the nanostrand bodies and the host matrix as combined.

5. A method as recited in claim 1, wherein said step of forming is conducted using a metal selected from the group consisting of nickel, nickel aluminides, iron, iron aluminides, alloys of nickel and iron, and alloys of nickel and copper.

6. A method as recited in claim 1, wherein each of said nanostrand bodies comprises a volume containing at least one nanostrand of filamentary metal, said at least one nanostrand has an average diameter in a range of from about 10 nanometers to about 4000 nanometers, and the average diameter of said nanostrand bodies is in a range of from about one micron to about 3000 microns.

7. A method for forming an electrically-conductive preform for use in imparting electromagnetic activity to a composite structure, the method comprising the steps of:

forming open structure electrically-conductive nanostrand bodies, the nanostrand bodies comprise branched, three-dimensional, open chains;

suspending said nanostrand bodies in a fluid carrier;

delivering said nanostrand bodies suspended in said fluid carrier against a forming surface; and

drying said fluid carrier from said nanostrand bodies delivered against said forming surface.

8. A method as recited in claim 7, further comprising a step of introducing a gelling agent to said fluid carrier.

9. A method as recited in claim 7, wherein said fluid carrier is water.

10. A method as recited in claim 7, wherein said fluid carrier is a solvent.

11. A method as recited in claim 7, wherein said step of forming is conducted using a metal selected from the group consisting of nickel, nickel aluminides, iron, iron aluminides, alloys of nickel and iron, and alloys of nickel and copper.

12. A method as recited in claim 11, wherein each of said nanostrand bodies comprises a volume containing at least one nanostrand of filamentary metal, said at least one nanostrand has an average diameter in a range of from about 10 nanometers to about 4000 nanometers, and the average diameter of said nanostrand bodies is in a range of from about one microns to about 3000 microns.