Issue 81, 2017, Issue in Progress

Dye-stimulated control of conducting polypyrrole morphology


Azo dyes represent important structure-guiding agents which exhibit non-covalent interactions of various types (ionic and hydrogen bonding, π–π stacking, hydrophobic interactions, etc.) allowing for their self-assembly in aqueous solutions and the subsequent formation of seeds or templates for the preparation of supramolecular structures of conducting polymers, especially polypyrrole (PPy). Three azo dyes (Acid Red 1, Orange G and Sunset Yellow FCF) bearing hydrophilic functional groups, with mutually different positions on a hydrophobic naphthylphenyldiazene skeleton, were used as structure-guiding agents in the synthesis of highly organized supramolecular structures of PPy in aqueous media. The synthesized polymers were studied by scanning electron microscopy, energy dispersive X-ray, and Fourier-transform infrared and Raman spectroscopies. Measurement of the conductivity revealed a moderate value of conductivity (around units of S cm−1) and reduced stability indicated by relatively fast conductivity decay. Infrared spectroscopy indicated a lower doping level of all PPy prepared in the presence of tested dyes compared to that of standard globular PPy. In contrast, Raman spectroscopy, which is a surface-sensitive method, indicated a slightly higher protonation level compared to that of standard globular PPy or nanotubular PPy synthesized in the presence of the well-known structure-guiding agent methyl orange. This discrepancy in the obtained doping levels is discussed and some consequences between the doping level of PPy and its conductivity are also pointed out.

Graphical abstract: Dye-stimulated control of conducting polypyrrole morphology

Article information

Article type
08 Sep 2017
17 Oct 2017
First published
06 Nov 2017
This article is Open Access
Creative Commons BY license

RSC Adv., 2017,7, 51495-51505

Dye-stimulated control of conducting polypyrrole morphology

S. Valtera, J. Prokeš, J. Kopecká, M. Vrňata, M. Trchová, M. Varga, J. Stejskal and D. Kopecký, RSC Adv., 2017, 7, 51495 DOI: 10.1039/C7RA10027B

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity