title: Polypyrrole Nanotubes and Their Carbonized Analogs: Synthesis, Characterization, Gas Sensing Properties.
abstract: Polypyrrole (PPy) in globular form and as nanotubes were prepared by the oxidation of pyrrole with iron(III) chloride in the absence and presence of methyl orange, respectively. They were subsequently converted to nitrogen-containing carbons at 650 °C in an inert atmosphere. The course of carbonization was followed by thermogravimetric analysis and the accompanying changes in molecular structure by Fourier Transform Infrared and Raman spectroscopies. Both the original and carbonized materials have been tested in sensing of polar and non-polar organic vapors. The resistivity of sensing element using globular PPy was too high and only nanotubular PPy could be used. The sensitivity of the PPy nanotubes to ethanol vapors was nearly on the same level as that of their carbonized analogs (i.e., ~18% and 24%, respectively). Surprisingly, there was a high sensitivity of PPy nanotubes to then-heptane vapors (~110%), while that of their carbonized analog remained at ~20%. The recovery process was significantly faster for carbonized PPy nanotubes (in order of seconds) compared with 10 s of seconds for original nanotubes, respectively, due to higher specific surface area after carbonization.
authors.affiliation: Department of Physics and Measurements, University of Chemistry and Technology Prague, Prague 6 CZ-166 28, Czech Republic. Jitka.Kopecka@vscht.cz.
authors.forename: Jitka
authors.initials: J
authors.lastname: Kopecká
authors.affiliation: Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, Zlin, CZ-760 01, Czech Republic. mrlik@ft.utb.cz.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Mrlík
authors.affiliation: Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, Zlin, CZ-760 01, Czech Republic. olejnik@ft.utb.cz.
authors.forename: Robert
authors.initials: R
authors.lastname: Olejník
authors.affiliation: Department of Physics and Measurements, University of Chemistry and Technology Prague, Prague 6 CZ-166 28, Czech Republic. kopeckyd@vscht.cz.
authors.forename: Dušan
authors.initials: D
authors.lastname: Kopecký
authors.affiliation: Department of Physics and Measurements, University of Chemistry and Technology Prague, Prague 6 CZ-166 28, Czech Republic. martin.vrnata@vscht.cz.
authors.forename: Martin
authors.initials: M
authors.lastname: Vrňata
authors.affiliation: Faculty of Mathematics and Physics, Charles University in Prague, Prague 8, CZ-180 00, Czech Republic. jprokes@semi.mff.cuni.cz.
authors.forename: Jan
authors.initials: J
authors.lastname: Prokeš
authors.affiliation: Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague 6, CZ-162 06, Czech Republic. bober@imc.cas.cz.
authors.forename: Patrycja
authors.initials: P
authors.lastname: Bober
authors.affiliation: Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague 6, CZ-162 06, Czech Republic. moravkova@imc.cas.cz.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Morávková
authors.affiliation: Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague 6, CZ-162 06, Czech Republic. trchova@imc.cas.cz.
authors.forename: Miroslava
authors.initials: M
authors.lastname: Trchová
authors.affiliation: Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague 6, CZ-162 06, Czech Republic. stejskal@imc.cas.cz.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Stejskal
keywords: carbon nanotube; carbonization; functionalized nanotube; heptane detection; polypyrrole nanotube