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

We present an experimental and first-principles study to describe the changes in the electrical conduct i v i t y 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 conduct i v i t y 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.

Automated summary

We conducted an experimental and first-principles study to investigate the changes in electrical conductivity properties of polyaniline Emeraldine Salt (ES) form synthesized using two different methods. The ES powders obtained through interfacial synthesis (PANI-I) exhibited higher electrical conductivity compared to the powders obtained through conventional synthesis (PANI-C). The study suggests that PANI-I differs from PANI-C in terms of its localized defect state, which significantly affects its intrinsic conductivity. Additionally, the study compared the bond lengths, dihedral angles, and relative stabilities of different states of the polymer and found that the ES Bipolaron state (ESB) and Polaron state (ESP) may coexist, and increasing the length of the polymer chain does not influence the relative stability between ESB and ESP defect states.