Bipolaron saturation in polypyrrole

Preparation and electrochemical performances of graphene/polypyrrole nanocomposite with anthraquinone-graphene oxide as active oxidant

“…4d that, GPy shows signals with high intensity and narrow linewidth, suggesting the presence of polarons as charge carriers [44]. Interestingly, a sharp decrease of ESR intensity is observed for AQ(D)S-GPy compared with GPy, suggesting the doping effect of AQ(D)S. It has been investigated that higher doping level leads more and more to double charging of the same chain segments so that bipolarons are formed and the ESR intensity falls [45,46]. Thus we attribute the decline in ESR intensity of AQ(D)S-GPy to the transition of the nature of charge carriers from the polarons to bipolarons.…”

Theoretical Modeling of the Doping Process in Polypyrrole by Calculating UV/Vis Absorption Spectra of Neutral and Charged Oligomers

“…[49][50][51] In the oligomer studies the issue of bipolaron formation was not addressed and the interpretation of polymer results remains controversial. 8,12,13,16,17,20,22,23,25,[52][53][54][55] Electronic structures of PPy and OPs have been investigated theoretically before; 20,[56][57][58][59][60][61][62][63][64][65][66][67][68][69][70] however, we are not aware of calculations of absorption spectra during the doping process of pyrrole oligomers or polymers. We have recently calculated such spectra for polyenes 71 and OTs.…”

Characterization and electrical properties of conductive polymer/colloidal graphite oxide nanocomposites

“…It can be seen in Fig. 7 that, undoped and doped PPy/CGO nanocomposites show signals with high intensity and narrow linewidth, suggesting the presence of polarons as charge carriers [34]. Furthermore, the higher ESR intensity of doped PPy/CGO nanocomposites, compared with the undoped one, implies the higher density and mobility of polarons, which contributes to the enhanced conductivity of doped PPy/CGO nanocomposites as shown in Table 1.…”