Effect of Morphology on the Response of Polyaniline-Based Conductometric Gas Sensors: Nanofibers vs. Thin Films
Guofeng Li, C Martinez, J Janata, J A. Smith, M Josowicz, Stephen Semancik
Mixtures of methanol with increasing fractions of formic acid were used to progressively transform the morphology of polyaniline starting from nanofibers to compact conventional films. It was demonstrated that the methanol/formic acid mixture could be used as a viable solvent system for nanostructured polyaniline to achieve sufficient processability while to great extent maintaining its microstructure. In addition, the effects of morphology on the response of polyaniline-based conductometric sensors to neutral gas molecules were examined. Although the nanofiber films demonstrated faster responses, they were found to have lower sensitivity than conventional thin films. It appears that creating high surface area nanofibril structures in polyaniline film does not effectively enhance sensor sensitivity due to the relatively open structure of polymeric materials and the adverse contribution from the interfibrillar contact resistance associated with nanofiber films.
Electrochemical and Solid State Letters
chemical sensor, morphology, polyaniline
Created October 1, 2004, Updated February 17, 2017