ELECTROCHEMICAL SYNTHESIS AND PROPERTIES OF POLY(AZURE B)

A blue poly(azure B) film has been synthesized using repeated potential cycling between -0.25 and 1.10 V (versus SCE). The electrolytic solution consisted of 2.5 mmol dm-3 azure B, 0.5 mol dm-3 NaCl and 0.2 mol dm-3 NaH2PO4 at the pH range of 2.0 to 11.0. The in situ visible spectrum during electrolysis of azure B shows that the intensity at 740 nm peak increases with increasing numbers of potential cycles, which is attributable to the formation of poly(azure B). The wavelength of its corresponding absorption peak is 98 nm longer than that of azure B. The polymerization rate is strongly affected by pH values. The anodic peak potential and cathodic peak potential of the poly(azure B) in a olution ofpH 3.0 are not affected by increasing the scan rate from 25 to 600 mVs-1, Poly(azure B) has good electrochemical reversibility and fast charge transfer characteristic in the pH range of 2.0 and 11.0. The conductivity of poly(azure B) is 1.5 × 10-4 Scm-1.According to the differences between FTIR spectra of poly(azure B) and azure B, an electrochemical polymerization mechanism of azure B is proposed in this paper.``