Doping of polyaniline by some redox active organic anions

Electropolymerized films of polyaniline (PANI) were doped by electrochemically driven anion exchange with some redox active species bearing anionic sulfogroups: indigotetrasulfonate (ITS), hydroquinone-2,5-disulfonate (HQDS) and 1,2-naphthoquinone-4-sulfonate (NQS). It was shown that ITS and HQDS can be bound by doping into PANI by simple potential cycling, provided in an acid solution containing the corresponding dopants. Both ITS and HQDS retain their own redox activity when bound to PANI and can be released from PANI by potential cycling in the supporting electrolyte. NQS was shown to react with PANI during potential cycling and to increase the redox capacity of PANI itself.