Hemoglobin-biocatalyzed synthesis of conducting polyaniline in micellar solutions

A new biomimetic route for the synthesis of a conducting complex of polyaniline (PANI)/sodium dodecylsulfate (SDS) is presented. Hemoglobin was used to catalyze the polymerization of aniline in aqueous micellar solutions of surfactants, such as SDS, hexadecyltrimethylammonium bromide (CTAB), and polyoxyethylene (10) isooctylphenyl ether (Triton X-100). The properties of these mimetic enzymatically synthesized PANIs strongly depend on the surfactants used in the formation of micelles as shown by the UV-vis absorption spectroscopy. The micelles formed by strong acid surfactants such as SDS are suitable templates for the enzymatic synthesis of conducting PANI. The pH on polymerization reaction of aniline was studied. The SDS micellar-templated polymerization of aniline is strongly pH-dependent in this case. A wider range at low pH (1.0-4.0) is required to produce the conducting PANI and optimal pH of 2.0. Varying concentrations of aniline, SDS and H2O2 in feed the favorable conditions for the production of PANI were determined. Cyclic voltammetry studies for the characters of PANI/SDS complex indicate the presence of a stable electrochemical active form PANI. (c) 2005 Elsevier Inc. All rights reserved.