Computational and experimental studies on the electrical conductivity of doped polyaniline, polyanisidine and polypyrrole

Issue Date

9-2006

Abstract

Computational and experimental studies were done on polyaniline (PAni), polyanisidine (PAnis) and polypyrrole (PPy) which include the computation of molecular properties and its correlation with the experimental electrical conductivity. The molecular structures of PAni, PAnis and PPy, in their undoped and doped states, were optimized in vacuo using the PM3 semi-empirical method (HyperChem software). The HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energies, HOMO-LUMO energy gap, bandwidth, dipole moment, heat of formation and total energy were computed. The emeraldine salt (doped form) of either PAni or PAnis was modelled as a tetramer for PPy, the polaron (doped form) was modelled as a pentamer. A high electrical conductivity was correlated with low HOMO-LUMO energy gap, high bandwidth and high dipole moment. Results of the computation predict that the perchlorate- and nitrate-doped PAni, PAnis and PPy have a fairly higher conductivity than the chloride-doped polymers. The results were confirmed by the measurement of the electrical conductivity using a two-point probe set-up. The IR results confirm the effect of protonic acid doping on the proportion of the quinoid and benzenoid resonance structures in PAni and PAnis. For PPy, IR spectra confirm the presence of pyrrole rings.

Source or Periodical Title

Materials Research Innovations

ISSN

14328917

Volume

10

Issue

3

Page

376-388

Document Type

Article

Language

English

Subject

Chemical synthesis, Conducting polymers, Electrical conductivity, HyperChem, Polyaniline, Polyanisidine, Polymer doping, Polypyrrole

Identifier

https://doi.org/10.1179/mri.2006.10.3.376

Digital Copy

YES

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