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Concomitant processes in the redox switching of polyaniline
Author(s) -
Gospodinova Natalia,
Mokreva Pavlina,
Terlemezyan Levon
Publication year - 1996
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/(sici)1097-0126(199609)41:1<79::aid-pi599>3.0.co;2-b
Subject(s) - polyaniline , redox , materials science , concomitant , chemistry , polymer , composite material , polymerization , mathematics , statistics , metallurgy
It is shown for the first time that the redox switching of polyaniline (PANI) under voltammetric conditions is accompanied by the following processes: oxidation of PANI by atmospheric oxygen in the range of low potentials ( E < 0.2 V); reduction with addition of aniline (post‐polymerization) at E > 0.2(5) V, which in the range 0.2(5) < E < 0.5 V compensates entirely for the oxidation over the timescale of the cyclic voltammogram. These processes determine: (a) the existence of the emeraldine (conducting) state in a potential window (instead of at a defined potential); (b) the fundamental asymmetry in the redox behaviour of PANI; (c) the difference in the rates of the oxidation and reduction transients and (d) the dependence of the electrochemical activity of PANI on the pH of the medium.