Flexible, semiconducting nanocomposite materials based on nanocrystalline cellulose and polyaniline

Patent metadata

Field	Value
Publication number	US-9384867-B2
Application number	US-201214007060-A
Country	US
Kind code	B2
Filing date	Mar 28, 2012
Priority date	Mar 29, 2011
Publication date	Jul 5, 2016
Grant date	Jul 5, 2016

Abstract

A new approach is conceived for the development of organic polymeric conducting materials synthesized from nanocomposites of nanocrystalline cellulose (NCC) and polyaniline (PANI). The process involves oxidative-radical polymerization of aniline in the presence of NCC using either in situ or emulsion polymerization. The resulting NCC-PANI nanocomposite material can be obtained in film or powder form and exhibits electrical conductive properties typical of semiconducting materials. Unlike PANI, a brittle conductive polymer, NCC-PANI nanocomposite materials can be engineered to possess significant flexibility, strength and/or hardness as a result of the NCC acting as a reinforcing scaffold. Depending on the preparation conditions, electrical conductivities for the NCC-PANI nanocomposite materials prepared according to this disclosure range from 9.98×10 −5 to 1.88×10 −2 S·cm −1 ; they could also have hardness ≧0.189 GPa or be formed into flexible films of tensile strength of the order of 9.74 MPa and stretch of the order of 0.54%. These unique electrical and mechanical properties render these materials suitable for use in a variety of value-added industrial products, such as batteries, electronics, electrical sensors, separation membranes, anti-static coatings for aerospace applications, as well as anti-corrosive coatings for automotives and other industrial applications.

First claim

The invention claimed is:

1. A nanocomposite of polyaniline and nanocrystalline cellulose (NCC) wherein said nanocrystalline cellulose (NCC) forms a scaffold of the composite and said polyaniline occupies voids of said scaffold, wherein said scafiold is defined by a naturally formed ordered arrangement in a helical assembly of a chiral neniatic liquid crystal phase of NCC, and wherein said nanocrystalline cellulose (NCC) comprises crystallites having a cross-section dimension of 5-14 nm and a length of 20-100 nm.

2. A nanocomposite according to claim 1 , wherein said polyaniline is granular.

3. A nanocomposite according to claim 1 , wherein said polyaniline is fibrillar.

4. A nanocomposite according to claim 1 , wherein said polyaniline in said composite is formed by polymerization of aniline in the presence of said nanocrystalline cellulose (NCC).

5. A nanocomposite according to claim 4 , wherein said polymerization is in situ polymerization.

6. A nanocomposite according to claim 4 , wherein said polymerization is emulsion polymerization.

7. A nanocomposite according to claim 1 , having an electrical conductivity in a range from 9.98×10 −5 to 1.88×10 −2 S·cm −1 .

8. A process for producing a nanocomposite of polyaniline and nanocrystalline cellulose (NCC) comprising polymerizing aniline in the presence of nanocrystalline cellulose (NCC), wherein said NCC forms a scaffold of the composite and the aniline polymerizes in the voids of the scaffold, wherein said scaffold is defined by a naturally formed ordered arrangement in a helical assembly of a chiral nematic liquid crystal phase of NCC, and wherein said nanocrystalline cellulose (NCC) comprises crystallites having a cross-section dimension of 5-14 nm and a length of 20-100 nm.

9. A process according to claim 8 , wherein said polymerization is in situ polymerization.

10. A process according to claim 8 , wherein said polymerization is emulsion polymerization.

11. A process according to claim 8 , wherein said polymerization is carried out in the presence of a protonic acid.

12. A process according to claim 8 , wherein said polymerization is carried out in the presence of an oxidant.

13. A process according to claim 8 , wherein said polymerization is carried out at a mass ratio of NCC to aniline of 2:1.

14. A process according to claim 8 , wherein said polymerization is carried out in the presence of a protonic acid and an oxidant in an aqueous vehicle at a mass ratio of NCC to aniline of 2:1 and a mole ratio of aniline to oxidant of 1:1.

15. A nanocomposite according to claim 1 , having an electrical conductivity in a range from 9.98×10 −5 to 1.88×10 −2 S·cm −1 .

16. A nanocomposite according to claim 6 , having an electrical conductivity in a range from 9.98×10 −5 to 1.88×10 −2 S·cm −1 .

Assignees

• Hamad Wadood Yasser
• Atifi Siham
• Fpinnovations

Inventors

• Hamad Wadood Yasser
• Atifi Siham

Classifications

• C08L1/04

  Oxycellulose; Hydrocellulose {, e.g. microcrystalline cellulose} · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• H01B1/20 Primary

  Conductive material dispersed in non-conductive organic material {(organic macromolecular compounds or compositions C08)} · CPC title

• C08L79/02

  Polyamines · CPC title