Ionic liquid improves the laccase-catalyzed synthesis of water-soluble conducting polyaniline

The laccase-catalyzed polymerization of aniline in sodium dodecyl benzene sulfonate (SDBS) micellar solution was studied in the absence and presence of an ionic liquid tetramethylammonium trifluoromethanesulfonate ([TMA]TfO). It was found that [TMA]TfO was able to lessen the negative effect of SDBS on the laccase activity, especially at high levels, and prevent the association of anilinium cation and SDBS anion. It was also found that low level of [TMA]TfO is beneficial to the synthesis of conducting polyaniline (PANI) probably due to the extension of the lifetime of aniline cation radicals by [TMA]TfO. In the presence of [TMA]TfO, all the polymerization systems were visually clear, and a maximum yield of water-soluble conducting PANI could be obtained at low level of [TMA]TfO and near the critical micelle concentration of SDBS.