Enzymatic synthesis of conducting polyaniline in micelle solutions

Peroxidase-catalyzed template-guided polymerization of aniline has been carried out in aqueous micellar solutions of surfactants, such as sodium dodecylbenzenesulfonate, (SDBS), hexadecyltrimethylammonium bromide (CTAB), and polyoxyethylene(10) isooctylphenyl ether (Triton X-100). The properties of these enzymatically synthesized polyanilines strongly depend on the structure of the surfactants used in the formation of micelles as shown by the UV-vis-near-IR absorption spectroscopy. The micelles formed by strong acid surfactants such as SDBS are suitable templates for the enzymatic synthesis of conducting polyaniline. In solution, the micelles may serve as nanoreactors for the aniline monomer prior to the reaction and provide the necessary low-pH local environment for the growth of conducting polyaniline. The formation of low-pH local environment is further confirmed by the pH change of the bulk solution after the loading of aniline onto the micelles. FTIR, NMR, and LrV-vis-near-IR absorption spectroscopy as well as cyclic voltammetry are used in the characterization of the synthesized polyaniline. The enzymatically synthesized SDBS micellar polyanilines are electrically active and soluble in organic solvents such as DMSO and DMF in emeraldine base form.