Hemoglobin-biocatalyzed Synthesis of Conducting Molecular Complex of Polyaniline and Lignosulfonate

A new biocatalyst route for the synthesis of a conducting polyaniline (PANI)/lignosulfonate (LGS) complex was presented. Four different catalysts such as hemoglobin (Hb), 5, 10, 15, 20-tetrakis (meso-hydroxyphenyl) porphyrin, iron (II) tetrasulfophthalocyanine and ferric chloride were used to polymerize aniline in the presence of a natural polyelectrolytes template LGS. The experimental results show that Hb is an effective catalyst in this case and the synthesis is simple, and the conditions are mild in that the polymerization may be carried out in lower pH (1.0–4.0) buffered solution and optimal pH of 2.0. Varying concentrations of aniline, LGS and H2O2 in feed the favorable conditions for the production of PANI were determined. UV-vis absorption, FTIR, elemental analysis, conductivity, cyclic voltammetry and thermogravimetric analyses confirm the formation of thermally stable and electroactive PANI.