Metal nanoparticle-decorated nanotubes for gas sensing

Patent metadata

Field	Value
Publication number	US-2018313775-A1
Application number	US-201715582172-A
Country	US
Kind code	A1
Filing date	Apr 28, 2017
Priority date	Apr 28, 2017
Publication date	Nov 1, 2018
Grant date	—

Abstract

Disclosed herein are embodiments of compositions for gas sensing and sensors utilizing the same. In one embodiment, a composition comprises carbon nanotubes and and polymer-coated metal nanoparticles bound to the carbon nanotubes.

First claim

What is claimed is:

1 . A composition comprising:
carbon nanotubes having an average degree of functionalization with carboxylic acid groups and/or hydroxyl groups that is less than 3 percent by weight (wt %) based on a total weight of the carbon nanotubes; and polymer-coated metal nanoparticles bound to the carbon nanotubes.

2 . The composition of claim 1 , wherein the polymer-coated metal nanoparticles are non-covalently bound to the carbon nanotubes.

3 . The composition of claim 1 , wherein the carbon nanotubes are substantially free of carboxylic acid functional groups and hydroxyl functional groups.

4 . The composition of claim 1 , wherein the carbon nanotubes comprise single-walled carbon nanotubes or multi-wall carbon nanotubes.

5 . The composition of claim 1 , wherein the polymer-coated metal nanoparticles each comprise a metallic core and a polymer layer covalently bound to the metallic core.

6 . The composition of claim 5 , wherein the polymer layer comprises a hydrophobic polymer.

7 . The composition of claim 5 , wherein the metallic core comprises a metal selected from a group consisting of palladium, iridium, rhodium, platinum, and gold.

8 . The composition of claim 5 , wherein the polymer layer comprises poly(vinylpyrrolidinone), and wherein the metallic core comprises palladium.

9 . The composition of claim 1 , wherein the composition is dispersed in an organic solvent.

10 . A sensor for detecting gas, the sensor comprising:
an electrode assembly comprising electrodes; and a gas-adsorbing material disposed between the electrodes of the electrode assembly, wherein the gas-adsorbing material comprises:
carbon nanotubes; and
polymer-coated metal nanoparticles bound to the carbon nanotubes.

11 . The sensor of claim 10 , wherein the electrode assembly is operatively coupled to a processing device, wherein the processing device is to measure changes in resistivity of the gas-adsorbing material that result from gas molecules adsorbed to the gas-adsorbing material.

12 . The sensor of claim 11 , wherein the sensor has detection limit of 100 ppm during operation in an ambient environment having a relative humidity from 0% to 80%.

13 . The sensor of claim 11 , wherein the sensor is adapted to selectively detect methane.

14 . The sensor of claim 10 , wherein the polymer-coated metal nanoparticles are non-covalently bound to the carbon nanotubes.

15 . The sensor of claim 10 , wherein an average degree of functionalization of the carbon nanotubes with carboxylic acid groups and/or hydroxyl groups is less than 3 wt % based on a total weight of the carbon nanotubes.

16 . A method of producing metal nanoparticle-decorated carbon nanotubes, the method comprising:
forming a reaction mixture by combining a first solution with a second solution, wherein the first solution comprises polymer-coated metal nanoparticles comprising metallic nanoparticles coated with a polymer, and wherein the second solution comprises carbon nanotubes; and heating the reaction mixture to a temperature greater than a glass transition temperature of the polymer for a time sufficient to cause the polymer-coated metal nanoparticles to bind to the carbon nanotubes forming the metal nanoparticle-decorated carbon nanotubes.

17 . The method of claim 16 , wherein the polymer-coated metal nanoparticles are fully-formed prior to forming the reaction mixture.

18 . The method of claim 17 , wherein the polymer-coated metal nanoparticles are non-covalently bound to the carbon nanotubes.

19 . The method of claim 16 , wherein an average degree of functionalization of the carbon nanotubes with carboxylic acid groups and/or hydroxyl groups is less than 3 wt % based on a total weight of the carbon nanotubes.

20 . The method of claim 16 , further comprising:
dispersing the metal nanoparticle-decorated carbon nanotubes in a non-aqueous solvent-based ink.

Assignees

• Palo Alto Res Ct Inc

Inventors

• Iftime Gabriel
• Smith Clinton
• Schwartz David Eric
• Zhang Yong
• Vedharathinam Vedasri

Classifications

• B22F1/102

  Metallic powder coated with organic material · CPC title

• B01J20/3204

  Inorganic carriers, supports or substrates · CPC title

• B01J20/327

  Polymers obtained by reactions involving only carbon to carbon unsaturated bonds · CPC title

• G01N33/0009

  General constructional details of gas analysers, e.g. portable test equipment (devices for withdrawing samples in the gaseous state G01N1/22) · CPC title

• G01N27/04 Primary

  by investigating resistance · CPC title