Experimental and Ab-Initio Investigation of the Electrical Conductivity of Emeraldine Salt

Ergönenç Yavas Z., Cevher D., Silis H. T., ÇIRPAN A., Gülseren O., Franchini C.

Journal of Physical Chemistry C, vol.127, no.14, pp.6813-6824, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 127 Issue: 14
  • Publication Date: 2023
  • Doi Number: 10.1021/acs.jpcc.2c07962
  • Journal Name: Journal of Physical Chemistry C
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, MEDLINE
  • Page Numbers: pp.6813-6824
  • Middle East Technical University Affiliated: Yes


We present an experimental and first-principles study to describe the changes in the electrical conductivity properties of the Emeraldine Salt (ES) form of polyaniline when using two different synthesis methods. The ES powders obtained by the interfacial synthesis method (PANI-I) exhibit higher electrical conductivity than that of the powders obtained by the conventional method (PANI-C). Investigation of the calculated band structure and density of states together with experimentally obtained optical-absorption spectra and the magnetic measurements indicate that PANI-I differs from PANI-C with respect to its localized defect state type which significantly alters the intrinsic conductivity. Furthermore, comparative studies of bond length, dihedral angles, and relative stabilities of Leucomeraldine Base, Emeraldine Base, ES Bipolaron state (ESB), and Polaron state (ESP) indicate that ESB and ESP states might coexist. Additionally, we confirm that increasing the length of the polymer chain to octamer in the unit cell does not influence the relative stability between ESB and ESP defect states.