Masters Theses

Zhe-Fei Li

Abstract

"A single-step, bottom-up technique based on a nanostructured conducting polymer has been used to fabricate sensors. Small amounts of aqueous solutions of aniline, a dopant, and an oxidant were placed on an interdigitated electrode array. Ultraviolet (UV)-irradiation of the solutions enhanced polymerization, yielding a highly porous film of polyaniline nanofibers with mean diameters of around 100 nm and lengths on the order of 1 µm. Solutions that were not irradiated formed bulk-like polyaniline films. Nanofibers and bulk polyaniline sensors were exposed to vapors in an argon carrier gas including: chloroform, a weak proton donor; toluene, a vapor that causes polymer swelling; and triethylamine, which alters the doping level. Because of their higher surface areas, the response times of the fiber sensors were faster than those of conventional bulk polyaniline sensors. Sensors were also fabricated from polyaniline/metal nanocomposites using the same one-step technique. The response of the polyaniline/Ag nanocomposite sensor was about a factor of 2-3 times faster than the polyaniline nanofiber sensor exposed to gaseous triethylamine, probably due to the strong interaction between nitrogen atoms and the metal nanoparticles. The thermal stability of polyaniline and its composites was studied by thermogravimetric analysis. These results suggest methods for the advancement of simple and environmentally-friendly production of nanostructured polyaniline-based sensors and electronic devices"--Abstract, page iv.

Advisor(s)

Blum, Frank D.

Committee Member(s)

Bertino, Massimo F.
Schwartz, Robert W.
Kim, Chang-Soo

Department(s)

Materials Science and Engineering

Degree Name

M.S. in Materials Science and Engineering

Sponsor(s)

National Science Foundation (U.S.)
Missouri University of Science and Technology. Department of Materials Science and Engineering
Missouri University of Science and Technology. Department of Chemistry

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2008

Journal article titles appearing in thesis/dissertation

  • One-step fabrication of a polyaniline nanofiber gas sensor
  • Simple way to fabricate polyaniline/metal nanocomposite devices for gas sensing application

Pagination

xi, 50 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2008 Zhe-Fei Li, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Conducting polymersGas detectorsNanostructured materialsPolymers -- Structure

Thesis Number

T 9879

Print OCLC #

785624753

Electronic OCLC #

905977998

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