Conducting polymer nanofiber sensors

• US 20050126909A1
• Filed: 12/11/2003
• Published: 06/16/2005
• Est. Priority Date: 12/11/2003
• Status: Active Grant

• Current Assignee: Aerospace Corporation, Regents of the University of California (University of California)
• Original Assignee: Aerospace Corporation
• Inventors: Huang, Jiaxing, Virji, Shabnam, Kaner, Richard B., Weiller, Bruce H.
• Granted Patent: US 7,226,530 B2
• Time in Patent Office: Days
• US Class Current: 204/418
• CPC Class Codes: G01N 27/126 comprising organic polymers
• CPC Class Codes: G01N 27/127 comprising nanoparticles
• CPC Class Codes: Y10S 977/953 Detector using nanostructure
• CPC Class Codes: Y10S 977/957 Of chemical property or presence

Abstract

Polymer nanofibers, such as polyaniline nanofibers, with uniform diameters less than 500 nm can be made in bulk quantities through a facile aqueous and organic interfacial polymerization method at ambient conditions. The nanofibers have lengths varying from 500 nm to 10 μm and form interconnected networks in a thin film. Thin film nanofiber sensors can be made of the polyaniline nanofibers having superior performance in both sensitivity and time response to a variety of gas vapors including, acids, bases, redox active vapors, alcohols and volatile organic chemicals.

Claims

1. A sensor for sensing the presence of a chemical vapor, the sensor adapted for interconnecting to an electrical monitor for measuring a reaction of the sensor to the chemical vapor, the sensor comprising,

a positive terminal, the positive terminal being conductive,

a negative terminal, the negative terminal being conductive, the terminals adapted for interconnection to the electrical monitor, and

a film of organic conductive polymer nanofibers extending between the positive and negative terminal for producing a change in conductivity between the positive terminal and the negative terminal as monitored by the electrical monitor when the film is exposed to the chemical vapor.

2. The sensor of claim 1 wherein,

the positive terminal and the negative terminal are made of gold.

3. The sensor of claim 1 wherein the positive terminal and the negative terminal are made of gold and the conducting polymer is polyaniline, the sensor further comprising,

a thiol surface layer disposed between the terminals and the film.

4. The sensor of claim 1 wherein,

the polymer nanofibers are selected from the group consisting of polyaniline nanofibers, polypyrrole nanofibers, polythiophene nanofibers, polytoluidine nanofibers, polyanisidine nanofibers, polymethylaniline nanofibers, polyethylaniline nanofibers, poly2-alkoxyanilines nanofibers and poly2,5-dialkoxyanilines nanofibers.

5. The sensor of claim 1 wherein,

the polymer nanofibers are polyaniline nanofibers, and

the chemical vapor is selected from the group consisting of an acid vapor and a basic vapor.

6. The sensor of claim 1 wherein,

the polymer nanofibers have diameters less than 500 nm and lengths less than 10 μ

m.

7. The sensor of claim 1 wherein,

the polymer nanofibers are polyaniline nanofibers having diameters less than 500 nm and lengths less than 10 μ

m.

8. The sensor of claim 1 wherein,

the polymer nanofibers are polyaniline nanofibers having distributed diameters of 50 nm.

9. The sensor of claim 1 wherein,

the polymer nanofibers are polyaniline nanofibers having distributed diameters of 30 nm.

10. The sensor of claim 1 wherein,

the polymer nanofibers are polyaniline nanofibers having distributed diameters of 120 nm.