| Abstract: | The electron spin resonance spectra of various acid-doped polyanilines were studied. There are three significant changes in the ESR spectra upon acid-doping as the acid concentration of the doping solution is varied from pH<3 to pH>1: (1) The linewidth decreases by a factor of three. (2) The intensity increases. (3) The spin density increases by a factor of twenty. By comparing the variation of the electric conductivity with the variation of the spin density upon acid-doping, it is proposed that the polyaniline prepared by chemical oxidation consists of various oxidized and reduced units, and that the pi-electron rearrangement upon acid-doping results in highly conductive radical cations. |
