Synthesis and use of aramid nanofibers

Patent metadata

Field	Value
Publication number	US-10160833-B2
Application number	US-201313871106-A
Country	US
Kind code	B2
Filing date	Apr 26, 2013
Priority date	Apr 26, 2012
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

Dissociation of a macroscale version of an aramid fiber leads to the nanofiber form of this polymer. Indefinitely stable dispersions of uniform high-aspect-ratio aramid nanofibers (ANFs) with diameters between 3 and 30 nm controlled by the media composition and up to 10 μm in length are obtained. ANFs can be processed in transparent thin films using layer-by-layer assembly (LBL) with superior mechanical performance.

First claim

What is claimed is:

1. A transparent film comprising a layer-by-layer assembled composite comprising a plurality of deposited layers, said layers comprising hydrolyzed aramid nanofibers and a crosslinker,
wherein said aramid nanofibers have diameters of 3 to 50 nm and lengths of 0.1-10 micrometers, and wherein said composite is 10 to 2,000 deposited layers.

2. The film of claim 1 , wherein said composite is 10 to 1,000 deposited layers.

3. The film of claim 1 , wherein said composite is 100 to 500 deposited layers.

4. A hierarchical transparent film comprising:
at least one layer comprising hydrolyzed aramid nanofibers and a crosslinker, wherein the aramid nanofibers have diameters of 3 to 50 nm and lengths of 0.1-10 micrometers; and
at least one layer of a polymeric material, wherein said polymeric material comprises polyurethane or polyacrylic acid.

5. A transparent film comprising a layer-by-layer assembled composite comprising a plurality of deposited layers, said layers comprising hydrolyzed aramid nanofibers and a crosslinker,
wherein said aramid nanofibers have diameters of 3 to 50 nm and lengths of 0.1-10 mmicrometers, wherein said crosslinker is glutaraldehyde.

Assignees

• Univ Michigan Regents

Inventors

• Kotov Nicholas A
• Yang Ming
• Cao Keqin
• Thouless Michael D
• Arruda Ellen M
• Waas Anthony M
• Siepermann Carlos A Pons
• Anderson Ryan M

Classifications

• D06M13/123

  Polyaldehydes; Polyketones · CPC title

• C08L77/10

  Polyamides derived from aromatically bound amino and carboxyl groups of amino-carboxylic acids or of polyamines and polycarboxylic acids · CPC title

• D01F6/605

  from aromatic polyamides · CPC title

• C08G69/32 Primary

  from aromatic diamines and aromatic dicarboxylic acids with both amino and carboxylic groups aromatically bound · CPC title

• Y10T428/268

  Monolayer with structurally defined element · CPC title