Polyaniline/carbon nanotube sheet nanocomposites

Patent metadata

Field	Value
Publication number	US-10464271-B2
Application number	US-201313987706-A
Country	US
Kind code	B2
Filing date	Aug 24, 2013
Priority date	Aug 27, 2012
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

A method allows for preparation of CNT nanocomposites having improved mechanical, electrical and thermal properties. Structured carbon nanotube forms such as sheet, yarn, and tape are modified with π-conjugated conductive polymers, including polyaniline (PANI), fabricated by in-situ polymerization. The PANI modified CNT nanocomposites are subsequently post-processed to improve mechanical properties by hot press and carbonization.

First claim

What is claimed is:

1. A method for forming a carbonized carbon nanotube nanocomposite, the method comprising:
stretching a carbon nanotube material up to a 33% strain to form a stretched carbon nanotube material;
immersing the stretched carbon nanotube material in a monomer solution, wherein monomer of the solution physically adsorbs onto carbon nanotube surfaces of the stretched carbon nanotube material;
polymerizing the monomer in-situ to form a layer of π-conjugated conductive polymer on the carbon nanotube surfaces of the stretched carbon nanotube material, wherein the π-conjugated conductive polymer essentially locks the stretched structure of the carbon nanotube material, and wherein the π-conjugated conductive polymer layer has a thickness from 3 nm to 20 nm;
hot pressing the stretched carbon nanotube material having the π-conjugated conductive polymer formed on the carbon nanotube surfaces thereof to form a consolidated carbon nanotube composite; and
carbonizing the consolidated carbon nanotube composite at a temperature of about 800° C. in an inert atmosphere to form the carbonized carbon nanotube nanocomposite.

2. The method of claim 1 , wherein the carbon nanotube material is selected from the group consisting of a carbon nanotube sheet, a carbon nanotube tape, and a carbon nanotube yarn.

3. The method of claim 1 , wherein the monomer is aniline.

4. The method of claim 1 , wherein the solution is an acidic aqueous solution and the monomer is aniline.

5. The method of claim 4 , wherein the π-conjugated conductive polymer is polyaniline (PANI).

6. The method of claim 5 , wherein the PANI polymer layer thickness is controlled by adjusting the polymerization time and the aniline concentration in the acidic aqueous solution.

7. The method of claim 1 , wherein the hot pressing step occurs at a temperature between 25° C. and 300° C. and a pressure between 1 MPa and 2 GPa.

8. The method of claim 1 , wherein the inert atmosphere is of nitrogen gas.

9. The method of claim 1 , wherein the carbon nanotube material is a carbon nanotube sheet.

10. The method of claim 9 , wherein the stretching of the carbon nanotube sheet prior to the in-situ polymerization step is performed in a dry environment.

11. The method of claim 1 , wherein the stretching of the carbon nanotube material prior to the in-situ polymerization step is performed in a solvent.

12. The method of claim 11 , wherein the solvent is selected from the group consisting of acetone, methanol, N-methylpyrrolidone, and ethanol.

13. The method of claim 1 , wherein the consolidated carbon nanotube composite has a tensile strength from 239 MPa/(g/cm 3 ) to 484 MPa/(g/cm 3 ).

14. The method of claim 1 , wherein the hot-pressed and carbonized carbon nanotube nanocomposite has a Young's Modulus from 9.0 GPa/(g/cm 3 ) to 17.1 GPa/(g/cm 3 ).

15. The method of claim 1 , wherein the stretched carbon nanotube material includes a delocalized π electron system on the carbon nanotubes thereof.

16. The method of claim 1 , wherein the hot pressing step reduces the thickness of the stretched carbon nanotube material having the π-conjugated conductive polymer formed on the carbon nanotube surfaces thereof by 10% to 50%.

17. A method for forming a carbonized carbon nanotube nanocomposite, the method comprising:
providing a carbon nanotube material;
wetting the carbon nanotube material with acetone;
stretching the acetone wetted carbon nanotube material up to a 33% strain to form a stretched carbon nanotube material having an extended, delocalized π electron system on carbon nanotubes thereof;
immersing the stretched carbon nanotube material in a monomer solution, wherein dispersion interactions between the monomer in the monomer solution and the extended delocalized π electron system of the stretched carbon nanotube material causes the monomer to be adsorbed onto carbon nanotube surfaces of the stretched carbon nanotube material;
polymerizing the monomer in-situ to form a layer of π-conjugated conductive polymer on the carbon nanotube surfaces of the stretched carbon nanotube material, wherein the π-conjugated conductive polymer essentially locks the stretched structure of the carbon nanotube material, wherein the π-conjugated conductive polymer layer has a thickness from 3 nm to 20 nm;
hot pressing the stretched carbon nanotube material having the π-conjugated conductive polymer formed on the carbon nanotube surfaces thereof to form a consolidated carbon nanotube composite; and
carbonizing the consolidated carbon nanotube composite at a temperature of about 800° C. in an inert atmosphere to form the carbonized carbon nanotube nanocomposite.

Assignees

• Nat Institute Of Aerospace Associates
• Nasa

Inventors

• Kim Jae-Woo
• Siochi Emilie J
• Wise Kristopher E
• Connell John W
• Lin Yi
• Wincheski Russell A
• Working Dennis C

Classifications

• H01B1/24 Primary

  the conductive material comprising carbon-silicon compounds, carbon or silicon · CPC title

• B29C2071/022

  Annealing · CPC title

• B29C70/682

  Preformed parts characterised by their structure, e.g. form · CPC title

• B29C70/42

  for producing articles of definite length, i.e. discrete articles · CPC title

• B29C70/887

  locally reinforced, e.g. by fillers (filler concentrated near the surface B29C70/64) · CPC title