Solid-state NMR study of N-15 labelled polyaniline upon reaction with DPPH

Z D Zujovic, M R Gizdavic-Nikolaidis, P A Kilmartin, Hicham Idriss, S D Senanayake, G A Bowmaker

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25 Citations (Scopus)

Abstract

The quantitative investigation of the radical scavenging properties of polyaniline (PANI) upon reaction with excess of the stable DPPH radical (a 4:1 ratio of DPPH to aniline units in the polymer) was carried out using N-15 and C-13 solid state NMR spectroscopy. During the process the polyaniline was oxidised so that the imine content increased from 45 to 65%. The extent of oxidation measured by NMR was confirmed by N1s XPS analysis. However, within a 30 min reaction time, about 85% of the DPPH radicals were scavenged as monitored by the decay in its EPR signal. This is about 20 times greater than the fraction of DPPH required to oxidize PANI from an imine content of 45-65%. An identification of further redox processes is required to explain the high degree of radical scavenging. At the same time, there was no evidence of significant chemical binding or trapping of DPPH in the PANI structure. (c) 2005 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)1166-1171
Number of pages6
JournalRussian Polymer News
Volume47
Issue number4
Early online date18 Jan 2006
DOIs
Publication statusPublished - 8 Feb 2006

Keywords

  • polyaniline
  • DPPH
  • solid-state NMR
  • polymers
  • biocompatibility
  • antioxidants
  • mechanisms
  • actuators
  • powder

Cite this

Zujovic, Z. D., Gizdavic-Nikolaidis, M. R., Kilmartin, P. A., Idriss, H., Senanayake, S. D., & Bowmaker, G. A. (2006). Solid-state NMR study of N-15 labelled polyaniline upon reaction with DPPH. Russian Polymer News, 47(4), 1166-1171. https://doi.org/10.1016/j.polymer.2005.12.058