Electrical Conductivity in Conjugated Polymers

Abstract

This chapter describes the electrical conductivity in conjugated polymers. The common electronic feature of pristine (undoped) conducting polymers is the rt-conjugated system, which is formed by the overlap of carbon pz orbitals and alternating carbon–carbon bond of length 5.6y. The chemical repeat units of the pristine forms of several families of conducting and semiconducting polymers—that is, trans-polyacetylene [t-(CH)], the leucoemeraldine base (LEB), emeraldine base (EB), and pernigraniline base (PNB) form of polyaniline (PAN), polypyrrole (PPy), polythiophene (PT), poly(p-phenylene) (PPP), and poly(p-phenylene vinylene) (PPV)—are illustrated in the chapter. The conductivities of the pristine electronic polymers are transformed from insulating to conducting through doping. Intrinsically conducting polymers are promising materials for shielding electromagnetic (EM) radiation and reducing or eliminating EM interference (EMI) because of their relatively high CJ and E and their ease of control through chemical processing. Intrinsically conductive polymers, especially polyanilines, can be used in the welding of thermoplastics and thermosets.