Please use this identifier to cite or link to this item: http://scholarbank.nus.edu.sg/handle/10635/91425
Title: Co-existence of external protonation and self-doping in polyaniline
Authors: Neoh, K.G. 
Kang, E.T. 
Tan, K.L. 
Issue Date: 1-Sep-1993
Source: Neoh, K.G.,Kang, E.T.,Tan, K.L. (1993-09-01). Co-existence of external protonation and self-doping in polyaniline. Synthetic Metals 60 (1) : 13-21. ScholarBank@NUS Repository.
Abstract: Polyaniline which possesses two simultaneous modes of doping, external doping by ClO4 - anions and self-doping by -SO3 - groups, has been synthesized by three different methods. In each of the methods, the self-doping is accomplished by the copolymerization of metanilic acid and aniline using either (NH4)2S2O8 or Fe(ClO4)3·9H2O as oxidant. In method I external protonation by HClO4 occurs during the polymerization process while in methods II and III treatment by HClO4 is carried out after the polymerization step. The effects of oxidant/monomer ratio and metanilic acid/aniline ratio on the physicochemical properties of the copolymers are investigated and comparisons are made with the self-doped polymer obtained from the sulfonation of polyaniline. Experimental techniques used for characterization of the polymers include X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) absorption spectroscopy, ultraviolet-visible (UV-Vis) absorption spectroscopy, elemental analysis, thermogravimetry and four-probe measurements. Under the conditions investigated, self-doping can constitute up to about half of the doping of a 50% protonated polymer. The external dopant, ClO4 - anions, are thermally less stable than the -SO3 - groups of the incorporated metanilic acid units. The latter as well as the -SO3 - groups covalently bonded to emeraldine base through sulfonation undergo thermal decomposition at a lower temperature than metanilic acid itself. © 1993.
Source Title: Synthetic Metals
URI: http://scholarbank.nus.edu.sg/handle/10635/91425
ISSN: 03796779
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

Page view(s)

37
checked on Feb 17, 2018

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.