Square-Wave Voltammetry of ClO[sub 4][sup −]-Doped Poly(phenylenesulfidephenyleneamine)

Abstract

The ClO4−ClO4− -doped poly(phenylenesulfidephenyleneamine) (PPSA) was electrochemically prepared and investigated with cyclic and square-wave voltammetry (SWV). The unusual electrochemical behavior of PPSA indicates that the dopant ClO4−ClO4− anions are bound in two energetically different sites. In the so-called binding site, the ClO4−ClO4− anion is coulombically attracted to the positively charged S or N sites on one chain and simultaneously hydrogen bonded with the N-H group on a neighboring polymer chain. This strong interaction causes a reorganization of the polymer chains upon cycling in 0.2MLiClO4/acetonitrile,0.2MLiClO4/acetonitrile, resulting in the formation of a networked structure linked together by these ClO4−ClO4− coulombic/hydrogen bonding “bridges.” However, in the “nonbinding site,” the ClO4−ClO4− anion is very weakly bound, involves only the electrostatic interaction, and can be reversibly exchanged when the doped polymer is reduced. The use of SWV also allows us to differentiate between these two types of sites in the bulk and at the surface. © 2001 The Electrochemical Society. All rights reserved.