Masters Theses


Zhe-Fei Li


"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.


Blum, Frank D.

Committee Member(s)

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


Materials Science and Engineering

Degree Name

M.S. in Materials Science and Engineering


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


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


xi, 50 pages

Note about bibliography

Includes bibliographical references.


© 2008 Zhe-Fei Li, All rights reserved.

Document Type

Thesis - Restricted Access

File Type




Subject Headings

Conducting polymers
Gas detectors
Nanostructured materials
Polymers -- Structure

Thesis Number

T 9879

Print OCLC #


Electronic OCLC #


Link to Catalog Record

Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.

Share My Thesis If you are the author of this work and would like to grant permission to make it openly accessible to all, please click the button above.